BIOL30010: Staying Alive - The behaviour, psychology and ecology of predator-prey interactions

SA4: Discuss what's the best background sample to be, including the issues with determining this and some examples to illustrate...

• A random one? (Endler 1978 etc.) • But not all random samples are equally cryptic (Merilaita et al. 1999, etc.) • If you match a rare background sample, you won't match most places you sit on • Testing the idea that it's best to be the most likely background sample; Is this moth a common or a random sample of the background? Not all samples are equally cryptic. If random could be a rare sample, but then wouldn't match. If common then would look similar to background.

SA6: Describe the research findings by Quiroga et al., (2005) on how the brain reacts to images of female actors...

• A single unit of cells in the left posterior hippocampus was activated exclusively by different views of Jennifer Aniston • "the unit did not respond to pictures of Jennifer Aniston together with Brad Pitt" • A single unit of cells in the right anterior hippocampus responded to pictures of Halle Berry • "Strikingly, this cell also responds to a drawing of her, to herself dressed as Catwoman and to the letter string 'Halle Berry'"

SA1: Provide the definition(s) for prey...

• An animal taken by a predator as food • An animal that is hunted & killed for food by another animal

SA7: Describe pursuit-deterrence signals, including the research findings by Cresswell (1994) to illustrate this...

• An aposematic signal need only signal unprofitability, not toxicity • Skylarks sing when chased as indicates high quality individual so predator gives up chase • Found that Merlins chased non-or poorly singing skylarks for longer periods compared to skylarks that sang well

SA7: Describe the inducible defences in Daphnia as an example of an awkward shape...

• An example of phenotypic plasticity as an enlarged head cap & spines grow • Only occurs if larvae develop in water containing chemicals from its predator (the tadpole shrimp)

SA8: Describe the 'confusion effect'...

• An important benefit of animals being in a group (especially in a large group) • It is a "reduced attack-to-kill ratio experienced by a predator resulting from an inability to single out & attack individual prey in a group" (Krause & Ruxton 2002)."

SA6: Describe the use of Masquerade to avoid recognition, including the past issue in terms of evidence and an example to illustrate this...

• Animal resembles an inedible object so that it will be misidentified (not-recognised) by potential predators or prey • Assumed to be true (but until 2010) no direct evidence that misidentification is involved, as opposed to failed detection, thus unclear if masquerade or background matching was the reason for success • E.g. Stick insect could be misidentified as stick or not detected against "sticky" background

SA11: Describe the trade-offs and use of prey colouration for confusing predators...

• Aposematic colouration reduces probability of attack but makes prey more conspicuous • Although distance-dependent defensive colouration can mitigate this trade-off. • Minimise effect/cost of trade off (plastic phenotypes) & also inducible defences.

SA1: Describe Predator-Prey (PP) interactions and name some examples...

• Are exploitative interactions e.g. Herbivory, Parasitism & Predation • Exploitative: fitness of one individual goes up at the cost of fitness to another individual only one benefits

SA4: Describe what do we mean by camouflage?

• Avoiding detection & recognition despite being "in plain sight"

SA7: Identify and describe the research on desperate predators, including the methods used and the findings...

• Barnett et al. (2012) used domestic chicks & dead mealworms, injected mealworms with water (defended), 1% quinine solution (mildly defended) or 3% quinine (moderately defended), these were discriminable with added colour cues • Allowed birds to learn difference & then birds given restricted diet so they dropped below free-feeding mass (FFM) • Found the hungry birds ate more defended prey

SA7: Identify and describe the research on distance-dependent defensive coloration in a certain amphibian, including the methods used and the findings...

• Barnett et al. (2017) used plasticine model frogs which were either: natural pattern (yellow & black); aposematism (plain yellow), & camouflage (brown-&- black). • Placed model frogs on natural leaf litter, leaf litter pictures, cleared leaf litter, or pictures of the average background colour as part of a randomized block design & recorded avian predation in rainforrest. • Found brown-&-black frog survival was background-dependent as survived best on leaf litter & leaf litter pictures, while yellow-backed frog survival was background-independent • Found the natural frog pattern's survival was more like the camo pattern as survived the best on leaf litter & leaf litter pictures

SA7: Identify and describe the research on distance-dependent aposematism in caterpillars, including the methods used and the findings...

• Barnett et al. (2018) looked at the Cinnabar moth caterpillar which eats ragwort & obtains toxic alkaloids • Calculated stimulation of a bird's red-green opponent colour channel when viewing caterpillar & ragwort stem from near & far (the luminance channel shows a similar pattern) • Found that although the caterpillars' stripes are highly salient /easily seen at close range, when viewed from a distance the colours blend together to match closely those of the background

SA5: Identify and describe the research on insect camouflage through distraction of birds, including the methods used and the findings...

• Dimitrova et al., (2009) had Blue tits looking for artificial prey on backgrounds of varying contrasts • The artificial prey had similar pattern to background • Found it took longer for the birds to find high contrast on high contrast, & also found high contrast survive better on low contrast too counter-intuitive

SA11: Describe the use of limited attention in terms of trade-offs, including the research finding by Milinski (1984) as an example to illustrate this...

• Direct mechanism that drives a trade-off between feeding & predation (not just activity that can drive predation-feeding trade-off) • Find it harder to detect predators when own prey confusing • E.g. Found sticklebacks as foragers find it harder to detect predators when attacking more confusing (larger) groups

SA8: Identify and describe the research on the change in motion unpredictably in a particular insect, including the methods used and the findings...

• Domenici et al. (2008) used wind stimuli at different angles on cockroaches in a circular arena & video recorded the behavioural responses to calculate the escape trajectories • Found true randomness not optimal, because that includes movement towards the threat • Found that each cockroach has a limited set of preferred escape directions, but switches between them

SA8: Describe some of examples for colour change to illustrate the issue with determining if the response is actually Protean...

• E.g. Cuttlefish can change colour but does this confuse predator & so is the change Deimatic or Protean? • E.g. Cryptic grasshoppers flash bright underwings when they fly off -> startle predator -> cover wings when land • Change appearance unpredictably - issue of does the colour change fool a predator

SA12: Describe an example to illustrate the translocation of consumed nutrients across habitat boundaries, also identify and describe research on this as evidence, including the methods used and the findings... Hint: 🌳∞🏞→ 🐟☖ + 🐻🐟 → 🐟<(⚰)→🏞or🌳🌳🌳

• E.g. Salmon when at adult stage bring biomass (from sea) back to stream & die in stream; but also get eaten by bears & about 50% gets taken onto land - well-studied effect of terrestrial predators consuming salmon • The terrestrial predators take carcasses (or nutrients they have consumed) on to land. • Quinn et a., (2009) used small platform viewing stands >20m in large stream side trees (to avoid affecting bears' behaviour) & used binoculars to observe brown bears preying on chum salmon, & when bears caught a fish the location of where the bear consumed it was mapped. • Examined fish carcass & recorded species, sex, distance from stream bank & whether it was consumed near the stream or in the forest. • Also tagged salmon with plastic disk tags to fin & later during observations noted the locations of living tagged fish & removed tags from dead ones including recording the cause of death. • Found 49% of salmon killed by bears were taken into the forest, while 68% of tagged salmon killed were missing (thus potentially being lost in the forrest).

SA7: Describe the various reasons why it is important for prey using aposematism to be conspicuous... Also, describe why being maximally conspicuous may not be the best...

• Easy to discriminate from background & can be seen from afar • Facilitates predator decision-making (saves predator's time) • Easy to discriminate from palatable prey • Reduces likelihood of error when attacking • Facilitates predator learning • Facilitates predator memory • Being maximally conspicuous isn't always best as some predators are naïve, while some are desperate & some predators are immune

SA2: Identify and describe the research on the albatross lévy results and other results being re-examined, including the methods used and the findings...

• Edwards et al., (2007) used a new, high-resolution data set of wandering albatross flights • Found gamma distribution not Lévy • Also reanalysed original albatross data & found "the extremely long flights, essential for demonstrating Lévy flight behaviour, were spurious" - so no evidence of Levy • Also reanalysed data from deer & bumblebees, but also not actually showing Lévy flights with new method of analysis • Thus critical of graphical log-log plotting method (originally used in past research) as not giving correct results

SA5: Identify and describe the research on disruptive coloration mechanism used by snakes etc, including the methods used and the findings...

• Egan et al., (2016) timed how long it took humans to spot artificial snakes on artificial leaf backgrounds either with or without shadows • The artificial snakes had two main colours & different variations in edge enhancement with control lacking the edge enhanced • Displayed these on computer screen; found it took longer to find snake with enhanced edges

SA1: Describe how predator-prey interactions are not just one behavioural event by describing the events involved...

• Encounter - before this don't know location • Detection - when close enough to prey • Recognition- recognise predator cues & prey cues • Deciding to attack prey - depends on cost • Capture - probability of this, want to max success rate

SA11: Identify and describe the research on the effect of light intensity on Guppy mate-attraction trade-off, including the methods used and the findings...*

• Endler (1987) used combination of large-scale lab & field observations • Predation increases with light intensity, males respond by reducing displays but maintain 'sneaky' copulations • Displays minimum at noon as males adjust behaviour to avoid predation through conspicuousness • Display colour decreases as light intensity increase • Sneaky mating = constant, but display more successful than sneaky

SA11: Identify and describe the research on Guppy mate-attraction trade-off, including the methods used and the findings...*

• Endler 1978: Cross population comparison of male guppy colour patterns in Trinidad • Physical barriers create variation in predation risk as further upstream = less predators • Found more predators -> smaller colour patches, decreased number of spots & less iridescence

SA5: Identify and describe in detail the research on false edges and low-level vision, including the methods used and the findings....

• Espinosa & Cuthill (2014) hid objects in pattern on computer e.g. hide circle on dark, white, or boundary between square & background • Predicted treatment that matches square in foreground & colour of background should do best • Found treatment hardest to find was treatment that matched foreground & background (so Cott correct) • Also found took longer to find, & missed more, cryptic targets when they matched two different objects than merely matching two different colours as interferes with perceptual grouping (so Cott was once again right)

SA7: Describe the explanation by Fisher (1930) on how post-ingestion toxicity evolve (e.g. how do the genes for toxicity spread when toxic animal eaten)...

• Evolves as siblings survive aka kin selection • Family grouping effects as predicted toxic animals would be aggregated e.g. batch of toxic caterpillar siblings on plant • If one dies, the other kin benefit, so gene spreads • Predator could use spatial cue (e.g. don't eat / avoid stuff that eats toxic plants) or the phenotype

SA14: Identify and describe the research on how the success imperfect Batesian mimicry may be frequency dependent, including the methods used and the findings...

• Finkbeiner et al., (2018) Carried out artificial butterfly experiments in Costa Rica & Ecuador. • Field sites chosen based on the known presence of Adelpha butterflies & active avian predators • Used artificial butterfly models in predation studies, A. iphiclus was the presumed toxic model, & A. serpa was the putative non-toxic Batesian mimic. • Evidence of avian attack, indicated by beak imprints on the plasticine abdomen. • Made 500 individuals of each phenotype for each field site & five of each of the butterfly phenotypes were set in alternating order & at least 4 m apart, & ~1 m above the ground • Artificial butterfly models were exposed to predators for 4 days, checked daily for avian predator attacks, & then removed • Butterfly abundance data for A. iphiclus & A. serpa were collected using a combination of trapping, netting, sighting/observation & larval collection on hosts. • Found in Costa Rica, where both species share similar abundances, predators more readily attack artificial butterfly models of the presumed mimic, A. serpa. • Found in Ecuador, where A. iphiclus (model) is significantly more abundant, both species are equally protected from predation. • Evidence that imperfect Batesian mimicry is frequency-dependent on the relative abundance of models & mimics in natural populations

SA7: Identify and describe the research on stotting and hunt success, including the methods used and the findings...

• FitzGibbon & Fanshawe (1988) observed Thomson's gazelles & their predators on long, intermediate & short-grass plains, if predators killed a gazelle = successful hunt • Found that gazelles more likely to stot to coursing predators e.g. wild dogs, than they were to stalking predators e.g. cheetahs • Found Wild dogs more likely to chase non-stotting gazelle & hunts were more successful on non-stotting gazelle

SA7: Identify (if possible) various examples of animals, plants and fungi that use toxins and antifeedants as secondary defences.... Hint: ⊠≈≈ 👑🐍 🐌 🕷 🐸 🐡 🍃🍇 🌸 🌳🍄 etc.

Animals, in order of toxicity: Box Jellyfish, King Cobra, Marbled Cone Snail, Blue-Ringed Octopus, Death Stalker Scorpion, Stonefish, Brazilian wandering spider, Inland Taipan, poison dart frog, puffer fish. • The plants are: castor oil plant (contains ricin), belladonna, deadly nightshade, oleander, hemlock, yew. • The fungi are, left to right: Satan's bolete, fool's webcap, deadly webcap, fly agaric, panther cap, Amanita virosa, death cap. • For some, the toxin is used for hunting, with defence a secondary advantage

SA8: Identify and describe the research on if eyespots deter predators, including the methods used and the findings...

• Kodandaramaiah et al. (2009) attached real butterfly wings to piece of wood, with dead mealworm attached between the wings • Presented two prey specimens in each trial, one with eyespot & other with painted-over eyespot, on log to great tits • Found eyespot-less prey was attacked first in 25 trials (out of 32 trials) so the birds avoided eyespotted prey

SA13: Provide the definition for regime shifts...

• Large, abrupt, persistent changes in the structure & function of an ecosystem

SA8: Identify and describe the research on change in motion unpredictably as a form of protean behaviour, including the methods used and the findings...

Herbert-Read et al. (2016) looked fish motion before & after attack (entropy) by analysing movements of Pacific blue-eyes when startled • Used a stimulus to mimic the strike of an aerial predator, which was introduced when the fish were in different locations within the arena. • Observed (filmed) how the fish's behaviour varied with the distance or direction they were facing in relation to the threat. • Found the fish's movement path increased in complexity after the "attack", as the fish's movements become less predictable in response to the perceived threat

SA2: Identify the two main methods / categories used to maximise encounter rates with prey as well as the research questions that they correspond to...

1. Active search • What's the best search strategy? 2. Sit-and-wait • How to avoid detection & what is best location?

SA3: Describe the different assumptions for detection on encountering conspicuous prey as well as cryptic prey in different scenarios, including some example to illustrate this, as well as what the shape of the response depends on...

1. Conspicuous prey: • Step function - the greater the distance the lower the probability of detection as predicted by models (not realistic for open habitats) • E.g. when there is a barrier detection is high when prey & predator on same side but drops when prey on other side • Sigmodal function - have gradual decrease in probability of detection • Exponential curve - have sharp decrease in probability of detection 2. Cryptic prey • Probability of detection either gets shifted to left (i.e. need to be close to detect) or the probability is always below 1 (e.g mimicry so predator has to be on top of prey to detect it) • Also has step function, sigmodal & exponential curve • Shape of response depends on habitat (e.g. effect of turbidity), the sensory systems of the predator (e.g visual effects will be different to olfactory cues over distance)

SA8: Briefly describe the main features of protean behaviour, including who came up with this idea...

Change unpredictably: • In motion - change direction suddenly (zig-zag) • In form (shape shifting) - don't send consistent signals • Humphries & Driver, (1970)

• Spines and hairs (pictures)

Irritant or 'urticating' hairs (from Urtica dioica, the stinging nettle) contain toxins. Electron micrograph of urticating hairs of tarantula

SA6: Describe how "complexity" of background etc. could be possibly quantified...

Quantifying "complexity" - no direct way to measure it but quantify it via "Sub-band entropy" - "Visual clutter" • Entropy measure of disorder in a system • Feature congestion metrics - more compression if more repetition in image • Areas in matrix change brightness rapidly, can also measure colour congestion, can measure line orientation and so capture how busy

SA14: Describe the possible reasons/advantages for prey or predators using thanatosis / "playing dead", including some brief research examples to back these ideas up... Hint:

Reasons/advantages if prey: • Lack of movement doesn't attract attention of predators, while if unexpected shpe may not be recognised by predators • If already seen then less likely to be eaten as dead associated with being parasitised or diseased e.g. texas horned lizards display thanatosis & also squirt noxious smelling blood at predators (Sherbrooke et al., 2010) - so possible costs to predator • Less likely to be killed if perceived as dead, while also allowing the prey to escape as may save energy for escape • Could be a prelude to startle behaviour to suprise predator so prey can escape e.g. Sherbrooke & Mason (2005) found texas horned lizards squirting blood caused negative attack responses in cayotes • Or could be warning colours on underside • Could be a signal to conspecifics that a predator is about (altruistic) • Could be used to prolong mating e.g. nursery web spider males fake dath to mate longer (Hansen et al., 2008) Reasons/advantages if predator: • Predator may play dead to ambush prey? Other reason: • Non-adaptive (pathological response to extreme stress) - seen in humans

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SA4: Describe the original definition of crypsis, including the disagreements over this, and the new suggested definition...

• "Cryptic prey resemble random samples of the visual background": (Endler 2006 - 1978) • Not masquerade (mimicry of particular objects) • Many now disagree with Endler's definition • "all traits that reduce an animal's risk of becoming detected when it is potentially perceivable to an observer" (Stevens & Merilaita 2009) • Not just being a 'random background sample', but still excludes mimicry - crypsis is about avoiding detection, not recognition

SA9: Describe the three different theories on how to pursue prey & intercept a target, including the problems associated with these... Hint:

• 1) Pure pursuit: Always fly toward target (deviation angle = 0), visual acuity is best for judging distance • 2) Deviated pursuit: Estimate target's future position (deviation angle constant, >0 i.e non-zero angle of target, so a straighter path to intercept) constant angle to right or left • For Pure & Deviated, the predator appears more to the side (90 degrees) to the target at the start, then falls behind (>90 degrees) until interception behind target • 3) Constant bearing (parallel): Most direct path, good for predictable target paths, prey stays in same visual position as predator moves so less clear predator is moving towards prey i.e. relative position of predator stays the same in target's visual field so 'motion camouflage' (line-of-sight angle constant) • Problem: pursuit & capture of moving prey is often limited by biomechanical constraints

SA3: Describe the findings from loads of research studies on predator and prey movement 'games', including the issues with some of these, and the findings of research looking at natural systems...

• 100s of studies find prey move to low predator density patches (when predators unresponsive) • Many studies (if include those on optimal foraging) find predators move to high prey density patches (when prey unresponsive) • But very few studying systems where both predators & prey are allowed to move between patches (Lima 2002) despite most common in real world • If +ve correlation between predators & prey: predators are 'winning', if -ve, prey are 'winning' • Find in natural systems both relationships & no correlation (Sih 2005) • May find no correlation as not enough selection pressure on predator or prey (e.g prey maybe tracking resources in environment) • Or could be due to both predators & prey equally effective at responding to each other spacially • Little work on this type of system

SA11: Describe the trade-off in terms of when to flee...

• A trade-off between minimising being detected & having a head start • Movement breaks crypsis so might never be discovered, but predator may get closer, & increased chance of capture if there's detection • Cryptic animal stay still but if predator close when flee → movement early → escape but detected • Best to stay still → max avoidance & detection • Best to flee → minimise capture

SA4: Identify and describe the research on cat coloration as evidence for Thayer's idea, including the methods used and the findings...

• Allen et al. (2011) • Look at correlation; pattern of different cat species & the habitat they occupied • Looked at phylogeny & describe pattern in way they develop via diffusion of chemicals to lay down patterns in womb • Use equations to define coat patterns • Found remaining correlation was associated with habitat type (e.g. Jaguars & dappled light)

SA14: Identify and describe the research on the influence of density on frequency-dependent selection by wild birds feeding on artificial prey, including the methods used and the findings....

• Allen et al., (1998): used a cross-over experimental design at 16 separate sites, with prey being cylindrical 'baits' of pastry that were brown or green • At each site, prey populations were presented either with initial frequencies of 90% brown prey & 10% green, or with 10% brown prey & 90% green • Six sequential feeding trials were performed at the given prey frequency & the frequency was then crossed-over & another six sequential feeding trials were completed. • Modelled relative selective preference for brown baits over green ones using estimates of the log relative risk ratio • Found (via ANOVA) highly significant difference among sites with different prey densities • Found prey density had a very strong influence as when in low-density sites, the common colour is eaten disproportionately more than the rare colour (apostatic selection), & when in high-density sites the rare colour is eaten disproportionately more than the common (anti-apostatic selection) - wot steady change occuring between the sites • Found that selection by wild birds feeding on brown & green pastry prey is frequency-dependent & that the strength & direction of this selection changes with prey density in a gradual & predictable way

SA13: Identify and describe the research on the potential conservation effects of predator-mediated coexistence on the herbivore richness and abundance in benthic eelgrass communities, including the methods used and the findings... Hint: 🚫=🐟 ≀⃤ + 💩 𝐕𝐒 🐟 [≀] + 💩 𝐕𝐒 🐟 _≀_

• Amundrud et al., (2015): Field experiment used artificial sea grass units (ASUs) made of frayed rope to mimic seagrass & randomly assigned these to one of 3 predator exposure treatments: (I) a full predator exclusion cage (mesh holes 4mm in diameter), (II) a partial predator exclusion cage (with 2 20x9cm windows) & (III) an uncaged ASU • For full & partial cage treatments, slow-release fertiliser satchels were placed outside the cages, while controls had empty satchels • Found top-down processes indirectly altered herbivore community structure due to indirect predator effects as they were mediated by changing species interactions among mesograzers (i.e. caused shifts in mesograzer community assemblage) • Found predators significantly affected the abundance of each mesograzer species & increased total mesograzer abundance • Found predators increased local mesograzer richness by indirectly increasing the abundance & incidence of rare species & decreasing (supressing) the abundance of common species

SA7: Describe the use of facultative aposematism AKA distance-dependent coloration...

• An aposematic signal which is only revealed when predator discover prey / is close enough • Combines crypsis at a distance with an aposematic signal when a predator close e.g. spatial frequency blending (mix fine & course detail)

SA1: Provide the definition(s) for a predator...

• Animal that hunts, kills, & eats other animals • "an organism that primarily obtains food by the killing & consuming of other organisms" especially: "an animal that preys on other animals"

SA1: Describe predator-prey interactions before animals were around by using phagocytosis in unicellular organisms as an example to illustrate this...

• Animals are multicellular eukaryotic organisms, but what looks very much like predation occurs between unicellular organisms too. • Happens with non-animals (multi-cellular) e.g. single cell amoeba eating other organism

SA6: Identify some of the possible ideas / theories that may explain imperfect mimicry...

• Animals have differences in perception from humans • Lots of alternative profitable prey • Costs of misclassifying as tasty is very high • Rapid decision-making needed • Biases in learning ("overshadowing")

SA12: Describe in detail the predator effects on nutrient dynamics (in relation to predator-prey interactions) including some examples to illustrate this.... Hint: 🌾🌾⟲ (×5) 🐃 🐃 🐃 🐃 🐃 v.s. 🌾🌾⟲ (×2) 🐃⤻🐆

• Any effect of predators on prey numbers, which prey sizes & species, distribution, etc. will affect availability of nutrients • Just having a change in animal species composition, fewer prey & another species (the predator), will shift the balance of nutrients in animal biomass relative to available nutrients & those in plants • E.g. If no predators & more prey → more nutrients go up & back down • E.g. if more predators & fewer prey → nutrients go into predator & go back down again • The effects will often have a behavioural basis • Many mechanisms possible, much research done in aquatic systems (or related to aquatic systems) • Although nutrient dynamics sounds complicated, many of these mechanisms are simple, & often have a behavioural basis at the level of the individual predator & prey

SA12: Describe the nonlethal effects of predation, including some examples...

• Any interaction between predator & prey, where the prey does detect the predator but that does not result in death of the prey, can have nonlethal effects. • Aka 'nonconsumptive' or 'sublethal' effects as an indirect effect of predators • Broadly, any plastic change in prey due to predators • E.g. inducible defences in Daphnia • E.g. Stress from out running predators etc.

SA2: Describe the ecological impact of search behaviour and the frequent assumption in models, including the findings of two research pieces as examples to illustrate this...

• Assume prey density is proportional to encounter rate with predators • Mols et al., (2004) looked at Great tit & density caterpillar prey • Found when prey density doubled the encounter rate increased only by 72%, also search time didn't decrease as much • Travis & Palmer (2005) used spatially explicit model of predator moving in a grid wrapped into donut shape so finite amount of space & no boundary (I.e. avoids boundary effect) • Varied spatial correlation in predator search (movement) & prey density to look at % increase in encounter • Found doubling of prey density from 4 to 8 only increases encounter rate by 25%, but doubling from 32 to 74 causes a 104% encounter rate increase • Indicates increase encounter rate in relation to prey density is dependent on prey abundance & aggregation

SA13: Identify the two main types of intraguild predation, and provide an example for each of theses.... Hint: 🐇⇉ 🐱 or 🐺 but 🐺→🐱 vs ▻<> ⇉ 🐟 or 🐡 but 🐟 ⇄ 🐡

• Asymmetric (unidirectional) e.g. Lynx & Coati kill & eat hare, while Lynx can also kill & eat Coati • Symmetric (mutual) - often age (size) structured e.g. large fish species predate each other & also eat smaller fish species

SA4: Identify and describe some of the camouflage strategies....

• Background matching - "Blending in" to prevents detection • Disruptive camouflage - Breaks up shape & form, prevents identification • Masquerade (a form of mimicry) - Makes you look like something irrelevant, promotes incorrect identification

SA6: Describe the differences between masquerade and background matching...

• Background matching requires the background to be present • Masquerade can work without the background (Skelhorn et al. 2010) because it's a classification error not a failed detection • Indeed the error may be more likely if the background isn't present (Skelhorn & Ruxton 2010)

SA7: Identify and describe the research on distance-dependent coloration, including the methods used and the findings....

• Barnett & Cuthill (2014) used paper moth-like targets pinned to tree bark, & baited with dead mealworms, to free-living avian predators • Paper treatments were; A = match oak bark; B = fade oak (control); C = average colour (control); D = yellow & black stripes; E = combo of A & D; F = faded/dull version of E. • Found treatment E had the lowest mortality as warning signal only show close up

SA1: Describe some examples of predator-prey interactions within ecological complexity...

• Bats prey to centipedes - selection pressure on bats • Moth prey try to breed, as do bats & centipedes • Also competition for all 3 species Effect evolution of species - depends on importance of pred-prey interaction

SA13: Identify and describe the research on the possibility of behaviour-mediated trophic cascades in a terrestrial food chain as a potential consequence of nonlethal effects.... Include the research methods used, the findings, and what this research indicates... Hints: E: 🌾🌿 >C(⦢⦢/\__⊃ verses 🌾🌿 >C(⦢⦢/\__⊃ + 🕷<(🍴) verses 🌾🌿 >C(⦢⦢/\__⊃ + 🕷<(😷🖌) F: 🕷<(🍴) / 🕷<(😷🖌) = >C(⦢⦢/\__⊃ <(↓🏃) + ↓🍴🌾+ ↑🍴🌿 verses >C(⦢⦢/\__⊃ <(❌🕷) = ↑🍴🌾+ ↓🍴🌿

• Beckerman et al., (1997): carried out experimental tests (in enclosures) of direct vs. nonlethal effects vs. controls by using predation spiders (un-modified) as direct effect, risk spiders with feeding mouth parts (chelicera) glued shut using no-toxic cement (so couldn't subdue prey) as non-lethal effect & control of no spiders. • Tested for density-mediated & behaviour-mediated trophic cascade patterns in 3 trophic level system (food chain) of spiders, grass-hoppers, & plants. • Tested for effect of spiders on grasshoppers by measuring daily activity time when assigned randomly to either a no predator (control) or predator (predation) treatment • Found no significant difference in grasshopper densities for either predation spiders, risk spiders, & control (no spider / no predation risk) • Found 18% reduction in grasshopper daily activity time when predation or risk spiders present • Found grasshopper mediated behaviour through a shift in foraging with a significant increase to damage of herbs for predation & risk spiders • Inverse trophic cascade as 2-level food chain control = lower herb damage & higher grass damage, but 3-level food chain treatments = higher herb damage & lower grass damage - indicates a diet shift or 'habitat' shift as more refuge in herbs

SA2: Provide the definition for an 'encounter' and describe this model... Hint: _(_🐐_)(_🐐_)(_🐐_)____________(__🐅__)____

• Before predators have information about the location of prey, before prey have information about the location of predators - i.e. outside of "zone" or detection distance • A simple model - once a prey is within the possible detection distance, an encounter has occurred, then the detection stage starts.

SA12: Identify and describe the research on the importance of translocation of consumed nutrients (e.g. salmon) across terrestrial habitat boundaries, including the research methods used... Hint: 🏞📏+ 🌿🍇 + 🐾<(🐻) + 🐁🐭🐿

• Ben-David et al., (1998): collected samples of berries & seeds from five plant species in 18 transects extending from the river to upland forest within different sampling stations that were 8 different distances away (0 to 1000m) from river. • Recorded the absence/presence of sign of predator activity, including the areas of activity & the distance from the river. • Collected muscle samples from 5 different species of small rodents (that consume these plants) which were caught in traps • Kept samples of muscle tissues & vegetation frozen until preparation for determination of stable isotope ratios. • Carried out stable isotope analysis, for δ15N which is marine-derived nitrogen, & for carbon as a control

SA13: Describe the various methods used in the research by Ringler et al., (2015.) on trophic cascades and mesopredator release... Hint: [🐀]→🍥→🔬____🐱→💩+🍥→🔬______⦃🐦🐣⦄_🎥🌛__🐦<(☠️)→📝

• Black rats were trapped in summer & winter both inside & outside tern colonies for 7 years on islands. • Black rat stomach contents were analysed to determine their diet & identified sea-bird feathers using a reference collection • Cat diets analysed from fresh scats collected in summer & winter, collected tissue samples (liver) for stable isotope analysis on nitrogen & carbon • Daily counts of carcasses on 4 sampling areas (50m x 50m) randomly selected within tern colonies & video recorded nesting birds at night. • Recorded tern carcass numbers from 3 categories: (1) preyed upon by cat & consumed at least in part (2) preyed upon by a cat but not consumed (3) carcass without evidence of predation.

SA8: Identify and describe the other research on if eyespots intimidate predators because they look like eyes, including the methods used and the findings...

• Blut et al. (2012) used dummies with eyespots with 'sparkles' in a natural upward position compared to dummies with eyespots with 'sparkles' in a non-natural position • Dummies were baited with a dead mealworm fixed on the body axis & left exposed on tree trunks, while two types of dummies were arranged in an alternating manner per experiment • Presence or absence of mealworms was regularly checked 1-3 times each day • Found survival of dummies with eyespots with natural position 'sparkle' was significantly higher than the survival of unnatural 'sparkle' eyespot dummies • Indicates that eyespots with eye-like 'sparkle' in correct place intimidate predators, as they look like eyes

SA4: Identify and describe the research on the presence and absence of patterns, including the methods used, the findings and what this indicates in terms of whats the best background sample to be...

• Bond & Kamil (2005) used computer-generated moths with patterns controlled by genetic algorithm • Blue Jays searched on screen & tapped on moths they saw, the moths evolved in response • Found selected moths became more cryptic & more varied, while non-selected & frequency-independent controls did not • If predators can't learn a specific pattern easily, it's best to be the commonest background sample • If predators specialise & learn a pattern, then polymorphism may result • So Endler may be right after all - being a random sample is best, because then predators can't learn your specific patterning.

SA9: Identify and describe the research on the pursuit strategy used by a particular bird of prey, including the methods used and the findings...

• Brighton et al (2017): used Peregrines that carried a GPS (logging position & speed) & wore a forward-facing camera on a harness, used drone aircraft to tow the winged food lure which would swing unpredictably for Peregrines to chase, the lure was released on a parachute upon capture. • Viewed videos of Peregrins hunting & attacking the lures & analysed these • Found not a single strategy used: both deviation angle & line-of-sight angle varied throughout chases • Instead use 'proportional navigation': brings predator eventually in parallel trajectory with target

SA1: Define endosymbiosis and describe the endosymbiotic theory...

• Bringing together of distinct cells, one inside the other • Major hypothesis for evolution of eukaryotes as mitochondria was originally free living prokaryote prey cells that were not digested (having own DNA supports this) • Life evolution possibly from predator prey interactions of amoeba thus leading to mitochdria as in system • So much of life may have depended on very early predator-prey interactions

SA11: Identify and describe the research on how activity drives predation-growth trade-off for a particular insect larvae, including the experimental methods used and the findings...

• Brodin & Johansson (2004): Compared damselfly larvae raised in containers with & without lethal predator in glass containers. • Found larvae reared under threat of predator were less active than larvae not exposed to predator • Found larvae reared under threat of predator had a smaller mean size than the size of larvae not exposed to predator • So found reduce activity leads to predation growth trade off as prey grow less as less activity

SA11: Identify and describe the research on how behavioural traits are affected by the risk allocation hypothesis, including the methods used and the findings...*

• Brown et al., (2005). •.Explains bolder prey behaviour from high predation sites • boldness = trade off between benefit & cost (pred) • High pred = more bold

SA2: Summarise the Brownian and Lévy movements....

• Brownian = lots of small random steps that are more evenly distributed • Lévy = mostly small random steps (similar to Brownian) but with a few large steps/leaps

SA13: Idenify and describe the research on whether the presense of mesopredators can be considered beneficicial in terms of regime shifts, including the various methods used, the research findings, and what this indicates.... Hint:

• Burt et al., (2018): annual subtidal surveys at 11 sites on central coast of British Columbia (Canada) • Measured red urchins & grouped them into 3 size categories; large (too big for sea star predation but can be eaten by sea otters), medium (easily handled & consumed by otters & sea stars), & small (can avoid predation by sheltering under the spines of large adults) • Explored cascading effects of sea otters & sea star, by using 4 predator scenarios: (i) both predators absent; (ii) sea star present but otters absent; (iii) otters present but sea star absent; & (iv) both otters & sea star present • Examine the relative differences in size-specific rates of urchin mortality, urchin grazing, & empirical density estimates of urchins & kelp • Found sea otters had the greatest impact on the mortality of large sea urchins, but that sea star decline/absence corresponded to a 311% increase in medium urchins & a 30% decline in kelp densities • Found kelp forest density highested (maintained) when both otter apex predator & sea star meso-predator present as they have the greatest contol of the urchin herbivore population • Indicates non-multi-predator system of only the otters isn't as effective at keeping herbivores in check to maintain species-rich ecosystems & that mesopredators are beneficial by facilitating regime shifts from urchin barrens to kelp forests

SA3: Describe the use of some information for encounters & define cues...

• Can follow cues (such as smell etc.) to prey • Cues are indirect sources of information.

SA12: Identify and describe the two pieces of research on the effect of the geographic variation on the Atlantic silverside fish, including the different methods used and the findings...** (check)

• Canover & Present (1990): used common garden experiment for several generations (thus isolate genetic effect) -> keep individuals in same conditions for many generations •.Growth rate: Nova Scotia > New York > South Carolina • Varied water temperatures -> found growth rate separated out more at higher temperatures, with effect greatest at higher temperatures • Found large scale patterns as slower intrinsic growth rates where growing season is longer • Canover (field expt); larger size protects against winter mortality - size after winter minus weight before winter-> spring length greater than autumn length (higher latitude) • Lab experiment: - predatory blue fish -> size selection -.Larger prey -> lower success in attack - counter gradient variation* -> difference in length cancelled out by growing rate • Higher temp indicates short growing season for high latitude fish so that's when they maximise growth the most • Larger size protects against mortality during winter (probably predation) • Juanes and Conover 1994: • Example of countergradient variation: selection on genes (intrinsic growth rate) opposes latitude gradient of growing season → same growth rates across latitudes • Bigger difference in mean size in spring vs. autumn for populations at higher latitude • Countergradient variation shown in growth rates of other animals, especially ectotherms

SA7: Identify and describe the research on immune predators, including the methods used and the findings...

• Common garter snake is immune to tetrodotoxin in the skin of a rough-skinned newt that could kill a bird, small mammal or even a human. • McGlothlin et al. (2014) sequenced genes from the Common garter snake using BAC library constructs • Found coevolutionary arms race between snake & newt has led to higher toxin levels

SA10: Describe the conventional lateralisation paradigm...

• Conventional lateralization paradigm suggests that individuals are left or right lateralized to increase efficiency/ aid specialisation of different tasks. • E.g. Lateralized behaviors could benefit individuals by increasing task efficiency in foraging & anti-predator behaviors.

SA2: Briefly describe how step lengths could be measure, including some research examples to illustrate this...

• Count step length based on grid cells • E.g. Iannou et al., (2016) used grids for saltatory searching in fish (unpublished) • E.g. McLaughlin et al., (2001) videoed fish swimming across grids in pools as part of field research

SA4: Describe some of the constraints of the body plan and motion...

• Creates a distinctive internal pattern, perhaps unlike anything in the background • Symmetry is highly salient in visual search (e.g. in humans & birds Cuthill et al (2006)) • Motion breaks camouflage • "No colour scheme whatever is of much avail to animals when they move, unless the movement is very slow and cautious" (Theodore Roosevelt) • "Common fate" of visual features, however well they match the background, binds them together in perception

SA12: Identify and describe the research and methods used to investigate the effects of non-lethal predation via the reintroduction of a certain predator to Greater Yellowstone Ecosystem...

• Creel et al., (2007) Elk were counted & calf-cow ratios were recorded by aerial counts, also assessed direct predation on calves by attaching eartag radiotransmitters to 30 newborn calves. • Used independent data on wolf numbers from near-daily ground radio-tracking & observation. • Collected fresh elk fecal pellets from the snow & stored them at -40˚C for fecal progesterone determination via ELISA. • Randomly sampled ≥ 10 pellets from sites that were clearly one defecation (using tracks), in the third trimester of Elk pregnancy (after March 15th).

SA5: Identify and describe the research on coincident disruptive colouration, including the two different experimental methods used and the findings for each of these...

• Cuthill & Szekely (2009) created wings & body of artificial moth, with 3 wings at midline, 1 dark, 2 light, & 3 two-tone & also make body two-tone, light or dark • Two tone body & wing so they match was coincident, but disruptive coloration; if no longer match • Found body & wing two-tone & match = best for survival as birds didn't target these • Additional mechanisms; conspicuous elements distract the predator's attention as Thayer argued that distraction acted as camouflage • Replicated with humans & computers, search for moths on pictures of bark with 10 original treatments + 'wings' without 'bodies' & trees without 'moths' • Measure response time & accuracy, & found same results as for birds so coincident disruptive coloration works (Cott was right (again))

Identify and describe the research testing Cott's ideas by using moths, including the methods used and the findings...

• Cuthill et al. (2005) used triangular "wings" & dead mealworms pinned to tree to track • looked "survival" over time as each replicate moth had a different pattern sample: - 2 monochrome treatments (brown & black) - 3 oak shaped pattern treatments that either intersect edge, no intersect 1 & no intersect 2 • Found edge survived best (overlap edge); • Oak pattern does better than monochrome; supports disruption • Cott said others must stand out too.

SA4: Identify and describe the research on the constraints of the body plan, including the methods used and the findings...

• Cuthill et al., (2006) tested the conspicuousness to avian predators of artificial, moth-like targets, with or without bilateral symmetry in background-matching coloration, against oak trees in the field • Found that asymmetrical 'moths' survive better because birds detect the symmetrical patterns sooner.

SA5: Identify and describe the research on optimising countershading camouflage, including the methods used and the findings... Hint: ☀️ or 🌥 for A)⊂⊃🍃 B)⊂⊃🍃 C)⊂⊃🍃D)⊂⊃🍃E)⊂⊃🍃F)⊂⊃🍃G)⊂⊃🍃

• Cuthill et al., (2016/17) produced large cylindrical paper "caterpillars" with different dorsoventral color gradient patterns • Patterns designed to counterbalance direct sun or diffuse illumination (e.g. A= cloudy day countershading, B= sunny day countershading) • Control patterns were uniform or two-tone • Exposed these "caterpillars" to sunny/direct & cloudy/diffuse light levels to determine survival • Found that cloudy i.e. gradual countershading does best in cloudy light, while sharp does best in sunny light, so depends on illumination

SA10: Describe the research by Romenskyy & Herbert-Read, et al., (not yet published?) on investigating which models are correct for 3D systems, including the methods used and the findings...

• Data put into a principal component analysis to work out which variables are important in which prey is targeted during attacks e.g. predator distance to prey & predator angle to prey, distance between prey & several prey-prey interactions • Predators actively targeting isolated individuals in 3D • Found largest factor was angle & distance from the predator to each prey, as all attacks occurred when a prey was within 90 mm of the predator, & predator attacked closest fish to it in 79% of strikes. • Also found nearest-neighbour distances, distance to centre of mass of group, & node score also contributed strongly to whether a prey was selected. • Demonstrates that Hamilton's original assumption that a predator could attack from anywhere within the group is valid when considering the structure groups adopt, & their use of space in three-dimensions.

SA7: Describe the use of Secondary defences, including the various different defences used and examples of these to illustrate...

• Deployed at the point of attack E.g: • Tough exterior (animals & plant seeds); e.g Agouti break the protective nut shell of brazil nuts • Awkward shape e.g. Puffa fish • Playing dead ("thanatosis") e.g. Opossum, King Fisher • Spines & hairs -may have toxins - e.g. tarantula flicks irritant hairs • Toxins & antifeedants- e.g. box jellyfish, blue ring octopus, poison dart frog, deadly nightshade, castor oil plants, fungi

SA3: Describe predators as optimal foragers via the Ideal Free Distribution, including the findings from research as evidence of this... (not fini - paper)

• Different patches with varying richness • When differences in input rates should match distribution of input • E.g. when 2:1 prey ratio the predator switch to richer patch • Need to assess prey & competitor abundance (directly or indirectly) • Assumes prey don't respond to predator abundance • Indirect can just be intake rate of prey • Milinski, (2018) observed preferences of stickleback fish predators to locations of tank based on food supply • Fish (predator) locations highly variable before prey • Preference for side A when x2 prey there (with ratio of fish fitting prey) • Preference for side B when x2 prey there (with ratio of fish fitting prey)

SA1: Identify the numerous ways prey living in groups reduces predation risk...

• Dilution - hard to focus on one prey • Group defence - keep predator at bay • Group vigilance - stay alert • Confusion - hard to attack one • Also affects feeding & sex

SA6: Identify and describe the research on background complexity & visual search, including the methods used and the findings...

• Dimitrova & Merilaita (2010) used wild-caught blue tits & before experiments, tits were trained to search for artificial prey items on an artificial background • Used two pattern backgrounds (simple & diverse), & 4 prey item categories: high internal contrast (high); low internal contrast (low); average contrast with marginal high; & average contrast with marginal low • Blue tits searched for prey on patterned background, found it took longer to find prey on 'more complex' backgrounds • Quantifying "complexity" - no direct way to measure it but quantify it via "Sub-band entropy" - "Visual clutter" • Entropy measure of disorder in a system • Feature congestion metrics - more compression if more repetition in image • Areas in matrix change brightness rapidly, can also measure colour congestion, can measure line orientation and so capture how busy

SA4: Describe the different steps that could be taken to avoid being killed (predated)...

• Don't be there to avoid encountering predator • Switch habitat • Spot predators and move away • Don't be detected; Hide • Match the background

SA12: Explain why don't southern fish grow as quickly, also Identify and describe the research on this, including the methods used and the findings...

• Due to the predation-growth rate trade-off • Lankford et al. 2001: presented mixed prey treatment groups to predators including: 1. Fast growing (northern) vs. Slow growing (southern) prey fish 2. Fast growing vs. Slow growing feeding regime 3. Recently fed vs. Unfed fish • Found northern prey more at risk of predation even when reared in same conditions • Found fast growing food condition more at risk • Found more at risk when recently fed (regardless of predator species & whether northern or southern populations) due to reducing swimming performance • Shows the underlying mechanism for why southern fish don't grow as quickly. • Shows the balance in the predation-growth trade-off shifts depending on growing season length e.g. in northern latitudes, getting to large size by the winter is all important.

SA9: Identify and describe the research on whether encounter rates or the confusion effect drives marginal predation, including the methods used and the findings...

• Duffield & Ioannou (2017): manipulated visibility of prey on screen as varied group size (exp 1) & density (exp 2) of prey, which was viewed on screen (so surface to area ratio constant) by stickleback predator • When varying group size, found sticklebacks were signicantly more likely to attack prey on the edges of groups • Found when varying density sticklebacks were also signicantly more likely to attack prey on the edge of groups • This finding is in direct contradiction to confusion effect as should increase with density (does induce confusion to some extent) • Indicates that encountering prey on edges is more important than confusion effect

SA1: Describe some reasons why not all predator-prey interactions have all stages, including how this can be useful...

• E.g. sometimes prey escape or predator decides not to attack • Some stages can always be absent • E.g prey not detected - camouflage • E.g prey can't detect predator • Having some stages that can be absent can be very useful to test for particular hypotheses

SA1: Describe examples to illustrate that animals are usually both predators & prey, including the different hierarchies, and why there tends to be bias in literature...

• E.g. toad eats insect, but toad eaten by snake • Top (apex) predators relatively rare in numbers, biomass & species diversity (increasingly so with increasing trophic levels) • Bias towards non-top predators as: - Smaller size (of the predators & their prey) easier to handle - Greater abundance - Models of predator-prey interactions in general - But, need to consider predator behaviour in context of the predator's anti-predatory behaviour

SA12: Describe the affect of geographic variation by using the fish found in the North and Mid Atlantic sea on East Coast of U.S. as an example to illustrate this...

• Ecological gradient (length of growing season) can balance trade off between predation risk e.g. individual-level optimal behaviour • Ecological gradient in temperature between the two: - North = fish have short growing season of 3-4 months - Mid Atlantic = fish have longer growing season of 9-10 months • Growth rate is twice up north as it is in the south -> same growth in 1st year

SA11: Describe the predation-feeding (risk) trade-off including a hypothetical example to illustrate this...

• Extremely common - attracted the most research attention E.g: - The prey forages closer to the refuge to minimise the risk of predation. - After some time, resources are depleted around the refuge. • Refuge (min risk) with abundant resources → prey pref patch • Resources get depleted overtime, so food further from safe refuge (low risk & low resources vs high risk & high resources)

SA13: Identify and describe the research on the use of niche partitioning in predator species in order to avoid conflict, including the methods used, the findings and what this indicates...

• Falk et al., (2015): Recorded male Katydid calls from 12 species for playbacks to bats & randomly chose a single call & repeated this call at average call period for each species • Caught 4 gleaning bat species (via mistnets across streams or hand-nets at roosts) which were released into flight cage & allowed to acclimatise. • Presented each individual bat with calls of 12 katydid species (in random order) from playback speaker in centre of flight cage & scored bat behavioural responses (0 = no response, 1 = ear movement, 2 = look at speaker, 3 = flies towards or lands on speaker). • Offered 15 species of wild katydids (including 12 species from exp) & tallied number of each katydid species eaten completely for each bat species • Found the bats are similar in morphology, echolocation signal design & prey-handling ability, but each species preferred different acoustic features of male song in the 12 sympatric katydid species • Indicates the gleaning bats species have differences in sensory preferences (biases) for prey-generated sounds.

SA3: Identify and describe the research experiments on the use of predator odour (olfactory) cues by prey animals, including the multiple diffetent methods used and the findings... Hint:

• Ferrero et al., (2011) examined 38 mammals, & found a chemical elevated in carnivores more than herbivores • Isolated chemical 2-phenylethylamine (PEA) from carnivore urine • Looked at receptor activity in mice brains to different urine samples • Higher activity in mouse olfactory receptor (TAAR4) for non-control • Indicates chemical is clear signal for predator so strong selection pressure for rodents to detect areas where predators are nearby • Carried out behavioural tests with rats in arenas with treated & untreated patches of two urine % concentrations • Found no response to water (control) • For 1% odour not much response (but more response for lion & synthetic high PEA urine) • For 10% high conc odour rats did respond to lion & high PEA urine, but didn't respond to depleted PEA urine

SA6: Describe why detection and recognition cannot be easily separated, including the two traditions in the visual search literature to illustrate this and the various aspects that can determine this... Hint: 🌲🌳🌴🌵🎄

• Figure-ground segmentation = find an object & separate it from non-relevant background • Target-distractor discrimination = objects already segmented (obvious object, looks different); distinguish 'target' from 'distractors' • In target-distractor discrimination, everything is a discrete object; but need to find right one • But 'distractors' can also be treated as a single background texture, against which the target must be detected • Partially a matter of scale & coding efficiency, but also neural representation as distractor & single background can be the same thing eg blade of grass vs grass field • A matter of scale & neural representation, so detection & recognition can be treated as separate processes, but they needn't be as not always simple in real life • Depends on having concept (what is known e.g. having concept of a tree to spot odd one)

SA3: Describe the effect of prey distribution (e.g. if prey spread out, how can predators respond?), including some research that demonstrates this...

• For aggregated prey - predator should do area concentrated search • Dispersed prey - predator should do the opposite to area concentrated search • Shows 'win-shift' or 'win-stay' when appropriate to prey distribution • Evidence by Hill et al., (2002) on juvenile plaice in lab fit predictions • Prey aggregated the plaice used concentrate search • Dispersed prey the plaice move on • Win-shift strategy - do different thing once eaten a prey

SA4: Describe the use of computer data to be relevant to Animals e.g. birds...

• For colour take calibrated photos & measure both red, green, blue cells & UV cells (create avian colour space) • If know sensitivity of cones can work out how much light stimulates them & then transform • For texture need to describe the background in terms of orientation & spatial frequency of edges • Use techniques from computer vision ("Gabor filters") for texture • Decompose the pattern of light & dark into lines of differing orientation and spatial frequency (coarse vs fine-grained detail)

SA1: Identify and describe the research that provides evidence for the dilution effect, including how this was detangled from other effect...

• Foster & Treherne., (1981) observed the number of attacks & attack success rate of fish on different group sizes of the Ocean skater (Halobates robustus) • These groups can't detect predator, with no group defence, not much movement (hence reduced confusion effect) & juveniles (no sex) not feeding • Found there were less attacks for larger groups & also less successful attacks for larger groups thus dilution is the mechanism involved

SA12: Describe the findings of the research by Creel et al., (2007) on the effects of non-lethal predation via the reintroduction of a certain predator to Greater Yellowstone Ecosystem, including what these findings may indicate....

• Found Elk change feeding & predator behaviour based on Wolf predator distribution, with stronger response in females, as Elk change aggregation, vigilance, foraging & habitat selection • Found both across populations & years, mean fecal progesterone concentrations correlated strongly with elk-wolf ratios as low progesterone values were associated with heavier predation pressure • E.g. found the lowest observed progesterone concentration being associated with the lowest calf-cow ratio (8 calves per 100 cows). • Also found that calf-cow ratios correlate directly with predation pressure. • Indicates that "wolf predation has indirect effects on elk dynamics, driven by costs of behavioral defenses that alter reproductive physiology & demography" • I.e. so reduced reproduction isn't actually a bottom-up (resources limited) effect in this case & is instead caused by top-down sub-lethal predation effect

SA13: Identify and describe the research findings by Johnson et al., (2007) on the presence of prey in relation to the top predator being rare, including what these different findings indicate... Hint: ↑🐕 (↓🐺) = ↑🐨 🐻 vs ↑🐑 (↑🐰+↑🐺) = ↓🐨 🐻

• Found effect of dingoes exceeded that of sheep, while effects of these species were of similar strength (but opposite direction, dingoes being associated with persistence & sheep with decline) • Found overlap with dingoes as a significant extrinsic factor that acted to protect ground-dwelling marsupials from decline & extinction • Suggests the effects of dingoes on the threat from mesopredators are powerful enough to override them - thus areas with removal of dingo caused intermediate predators (e.g. fox) to increase • Found overlap with sheep affected persistence, indicating habitat changes caused by sheep grazing contributed to marsupial declines; possibly due to increasing the exposure of marsupials to predation; or because rabbits are very abundant where sheep are grazed & foxes prey heavily on rabbits

SA13: Describe the findings of the research by Vance-Chalcraft et al., (2007) on the consequences for prey in relation to the different types of Intraguild predation, including what these findings indicate.... Hint: If P♘⇉ (A ⇄ C🐆) then A or C🐆 = 𝐱↓P♘ but if P♘⇉ (A ← C🐆) then A or C🐆 ≠ 𝐱↓P♘ as C🐆 = >𝐱↓P♘ than A

• Found the intermediate predator was more effective than the top predator at suppressing the shared prey when alone • Found adding a top predator increased prey density (by reducing predation on prey) due to the top predator causing a reduction in the density (or feeding rate) of the effective intermediate predator • Found adding an intermediate predator decreased prey density (by increasing predation on prey) • Found this varies by ecosystem though as adding a top predator tended to release prey in terrestrial invertebrate ecosystems, but in lotic & terrestrial vertebrate ecosystems tended to show prey suppression with the addition of a top predator. • Indicates its not mutual IGP (despite prey safer / population less suppressed when both predators present) & is instead unidirectional IGP as when alone the intermediate predator was more effective at suppressing shared prey than top predator (if mutual then both predators alone would be equally effective)

SA12: Describe the findings of the research by Ben-David et al., (1998), including what these findings provide evidence for...

• Found δ15N values for blueberries were significantly greater at 0 & 50m than at > 50m from river, spruce seed δ15N exhibited a similar decline with distance etc (didn't detect a trend in %C control in relation to distance from streams) • Found values of δ15N also decreased with distance from streams for muscle samples from deer mice, voles, shrews, & squirrels • Found δ15N values from plants in relation to activity of piscivorous predators were generally higher in active sites, but only blueberries showed any significant differences in total nitrogen content as a % of dry weight • Provides evidence that nitrogen from salmon carcasses contributes to nitrogen pool used by plants in terrestrial ecosystems • Ecological effect dependent on whether N is limiting plant productivity

SA11: Describe how the prey being bigger reduces risk, including the associated trade-offs...

• General, not universal, pattern e.g. research by Skelly (1992) suggests that large tadpoles may have been less responsive to predator presence than small ones. • Even top predators are often susceptible as juveniles • Favours fast growth rate of young • So trade-off in prey between current anti-predation & future anti-predation • More complex than just what you need to achieve high growth rates increasing predation risk • So not only does reaching maturity earlier improves reproductive success in terms of offspring, but also can reduce predation risk when predators are less able to successfully attack larger prey

SA8: Identify the various escape behaviours that are used by prey...

• Get a head start e.g. vigilance, startle display, deflection marks • Be fast - life-dinner principle • False motion ('dazzle') • Protean behaviour e.g. unpredictable motion ("protean movement") & change appearance (possibly including iridescence)

SA11: Identify and describe the relatively more recent research on mate-attraction trade-off for Guppies, including the methods used and the findings...*

• Godin and McDonough 2003: binary choice between sized matched male guppies differing in colour brightness • & free-swimming trials • predators prefer bright colour males as more likely to attack

SA1: Identify and describe the research on predator-prey arms race (coevolution) of a certain bat species...

• Goerlitz et al. 2010: Looked at 'Stealth' echolocation (lower amplitude) in barbastelle bat (Barbastella barbastellus) which eats mainly eared moths • 10 to 100 times lower in amplitude than those of other similar bats • Compared similar species (Nyctalus leisleri) with fewer moths in diet, found Barbastelle reduces detection distance so not heard by moths, calls harder to hear • So Barbastelle overcomes prey hearing at the cost of reduced detection distance

SA13: Describe some of the effects of predator-mediated coexistence on biodiversity...

• Greater diversity in trophic level below when population densities are top-down limited (i.e. increase biodiversity via top down control) • Mechanism involves selective predation on competitive dominants reducing competition between prey, promoting prey coexistence & thus increasing prey biodiversity • Opposite to bottom-up limited where predator competitive exclusions can limit biodiversity

SA9: Describe the ideas behind predators targeting marginal prey...

• Hamilton (1971) etc. argue encounter rates drives marginal predation • Milinski etc. argue confusion effect drives marginal predation • Or could be selfish herd as selfish individuals try to reduce encounter rate so others more likely to encounter edge

SA10: Describe the idea of the selfish herd in two-dimensions, including who came up with this idea and what are the problems associated with this model... Also, describe the alternative suggestion by another scientist...

• Hamilton (1971) introduced idea of selfish herd, where individuals in a population attempt to reduce predation risk by putting other conspecifics between themselves and predators • This was later critiqued due to some of the assumptions unlikely to be true • Criticised as model assumes predator can target any prey with some likelihood of capture • Boundaries in the environment not considered • Vine (1971) suggested that groups should form different 3D structures depending on their location with respect to boundaries in the environment. • In particular, if individuals attempt to minimise their domains of danger from predators attacking from the outside of groups, then they should form flat circular configurations at boundaries, whereas they should form spheroid structures in open space.

SA3: Illustrate the importance of spatial scale when avoiding predators by identifying and describe the research on this, including the methods used and the findings... 1⎛_•_•_•_•__|______•_•_⎞3 Hint: • = r 2⎝_•_•______|_______•__⎠4

• Hammond et al., (2012) used design of splitting up experimental arena into 4 sections with different quantities of prey food patches (in each) • Arena separated into 2 halves to get separate spatial scales with 1 larger scale (hard to travel between) & 2 smaller scale (easy to travel between) in order to mimic wider world • Observed treefrog tadpole(s) prey & larval blue-eyed darner predator distributions both alone & together • If spatial coincidence is 1 then predator & prey are in same patch • Found for large scale had +ve correlation for predator & prey being in the same locations (close to 1) • Found for small scale habitat with low resources there was a -ve correlation • Found small scale habitat side with high resources had +ve correlation - so prey may be trading off food for predation risk

SA3: Identify and describe the research on predator searching techniques used for different prey distributions, including the methods used and the findings...

• Haskell., (1997) used experiments & a model examining to observe the search methods & learning of ferrets • When aggregated prey found they used small search area I.e. area restricted search. • Changed prey distribution so dispersed, predator did same method until detect new area with prey • Found increased in path length of ferrets only after they discovered a prey item after prey were moved apart. • Evidence that predators learn the distribution of prey & adjust their behaviour accordingly.

SA10: Identify and describe the research on information transfer in varied densities of fish schools, including the methods used and the findings...

• Herbert-Read et al., (2015) observed the response of varied group sizes of Pacific blue-eye fish to a simulated predatory attack (paddle) as an artificial aerial threat, in a ring shaped (annulus) arena & both filmed & electronically tracked individuals during escape behaviour, to analyse how the escape wave propagates through a fish school. • Fish were allowed to form a polarised group swimming clockwise around the annulus arena • Found the stimulus usually caused the fish to turn and swim anti-clockwise & that after the stimulus was presented ~10% of fish were moving at over twice the average initial speed, which raised the question if 'faster moving individuals are allowing info to be propagated through the group?'

SA10: Identify and describe the research on whether a 'proto-cooperative' hunting strategy (not spatially coordinated) could benefit individual hunters in groups & if it allows higher capture success than solitary sailfish, including the methods used and the findings from this...

• Herbert-Read, Romanczuk, et al., (2016) used behavioural observations & image analysis (slow motion) to quantify sailfish group hunting strategies • Sailfish use their bill (rostra) to slash sardines & knock them off balance in an attempt to capture individual fish • Found only 24% of these attacks resulted in a successful capture & never observed a sailfish to handle or ingest two or more fish at once • Found sardines' scales were removed from body when in contact dcontact with sailfish's bills causing damage to sardines in 95% of cases & that more fish were injured per attack than were caught, so many injured sardines in schools • Sailfish caught individual sardines at an average rate (across all the schools) of 0.66 (± 0.17) sardines per minute. • Found a positive correlation between the school's injury level & the capture rate; sardines in more injured schools were captured more quickly as injured fish were observed to break off from school as they could not keep pace • But doesn't explain why they hunt in groups, as a solitary hunter could get these benefits by hunting on its own.

SA9: Identify and describe the research on the evolution of a larger gap size, including the methods used and the findings...

• Higham et al (2007): analysed body size with gape size for 18 species of Cichlids, including phylogenetic analysis • Body size positively correlates with gape size - confounding effect? • used residuals & found strong correlation between relative gape size & ram speed (i.e. faster = bigger gape) • Control for phylogeny: gape size still positively correlates with ram speed

SA8: Identify & describe the research on the impact of direction of stripes in terms of the confusion effect, including the methods used and the findings...

• Hogan et al. (2016): Participants had to track the movements of the target square (with either horizontal, vertical & random stripes) using a mouse-controlled on-screen cursor • Found stripes parallel to the direction of motion enhance the confusion effect, as parallel stripes had the highest targeting error

SA8: Identify and describe the research on the confusion effect as an example how it reduces successful attack, including the methods used and the findings....

• Hogan et al. (2017) used human participants who controlled peregrine falcons while using them to attack animated virtual starling flocks • Investigated the influences of the size & density of the flock on the ability of a 'predator' to visually track & capture a target • Found targeting error increases with both flock size & flock density

SA8: Describe the argument by Skelhorn et al. (2016) on the "Deimatic behaviour" of katydids in the research by Umbers & Mappes (2014) ...

• If the katydid is toxic/noxious then maybe using conditional aposematism rather than deimatic (e.g. 'distance-dependent signalling') • Argues that a deimatic display evokes innate startle reflexes (classic fear responses) rather than being learnt avoidance (aposematism) • Argues should define deimatic display as any defensive display that causes a predator to misclassify a prey as a potential threat to its immediate safety • If revealing conspicuous colour patterns causes predators to fear = deimatic. • If display causes the predator to classify the katydid as unprofitable prey item = aposematic.

SA7: Describe why the evolutionary dynamics between the mimic & model for Mullerian mimicry are different from those in Batesian mimicry, including an example to illustrate....

• In Batesian the model suffers a cost so there are selative pressure on model to evolve away • In contrast there is pressure on model to evolve towards a Mullerian • However the species involved in Mullerian mimicry are not necessarily equally defended / toxic e.g. Monarch more toxic than Viceroy so get quasi-based mimicry (cross of Batesian & Mullerian)

SA6: Describe the effect of background complexity on camouflage...

• In camouflage, it pays to match the background, but the background itself can sometimes affect detection • So could influence habitat choice

SA12: Describe the effect of habitat in terms of the structural complexity...

• Increases prey density; structural complexity & density affects predator consumption rate • Acts as refuge so hard to find prey in habitat

SA11: Describe the effects of activity in terms of predation verses feeding, also Identify and describe the research on this, including the methods used and the findings...

• Increasing activity increases encounter rate with food & predators • Activity can also increase when looking for a mate, courtship behaviour, caring for young, etc • Brodin & Johansson (2004) compared different genotypes of damselfly as had container containing 1x1 square grid & measured activity of larvae, then exposed some individual larvae to lethal predator in containers. • Found larvae reared under threat of predator were less active than larvae not exposed to predator • Found larvae reared under threat of predator had a smaller mean size than the size of larvae not exposed to predator • So found benefit of activity as activity increase → growth increase, but trade off as more active (when predator present) → survival decrease

SA13: Define and describe the concept of trophic cascades in a predator-prey context, including identifying and describing research on mesopredator release as an example of this... Hint: 🏝: 🐦🐣 ⇉ (🐀 → 🐱) vs 🐱🔫 = ↑🐀 ∴ ↓🐦🐣 →🐀

• Indirect interactions (across a minimum of 3 feeding levels) triggered by addition or removal of top predators thus causing changes in relative populations of other predators & prey in food chain • Theses cascades can occur with & without IGP • If apex predator population declines → increase in small predators (mesopredators) further down food chain → often negatively impacts prey populations • Ringler et al., (2015.): looked at a case of intraguild predation on tropical islands • Cat & black rat (both invasive) predate seabirds, but cats also consume the rats. • When cats exterminated, rat predation on the seabird increased beyond that occurring when cats were present.

SA4: Describe what the visual cortex does for the brain to quantify colour and "texture" (pattern)...

• Info enters area V1 - Mostly edge detection • Info extracted in V2 - Simple features & contrast from light to dark, spacial frequency & colour etc. • V4 - Features assembled into objects & features of complexity

SA2: Describe when encounter rates matter more based on ecological factors, including some examples to illustrate this, as well as the outcome from these...

• Information regarding the location of prey / predators is low • E.g. In habitats where predator & prey (PP) densities are limited usually due to low primary productivity (e.g. biomasses low in ocean) • Also in complicated habitats (e.g. jungle with a lot of vegetation) so detection distances / sensory ranges limited - maybe high concentration of prey but predator struggle to detect them • Other things in complex habitats such as physical structure (e.g. rocks), turbidity, low light levels (equivalent for other sensory modalities - e.g. noise pollution from human activity.) • Means that encounter rates impose more selection pressure in these cases

SA1: Describe predator-prey arms races (AKA coevolution) including the bat-moth coevolutionary arms race (one of the best studied) as an example...

• Interactive, inter-specific evolution results in diversity of adaptations, & some very specialised ones. • E.g. Bats evolve echolocation to hunt in darkness as reduces risk to own predators, & reduces detection by prey if they can see. • Moths evolve to hear echolocation as close match between the frequencies at which moths hear best & the bat call frequencies (that prey on them) • Some bats evolve "stealth" echolocation (reduce detection), while some moths evolve high-frequency clicks to jam bat echolocation

SA7: Describe why Aposematism often uses contrasting colours...

• Internal contrast increases visibility independent of background • Internal contrast increases distinctiveness from palatable prey • Internal contrast increases memorability independent of background • e.g. yellow and black; if predator has colour vision this gives high contrast

SA8: Identify and describe the research on confusion in fish, including the methods used and the findings....

• Ioannou et al. (2009) Present groups of Daphnia in test tubes (with varying group sizes, densities & areas) to habituated, naive, & hungry sticklebacks • Found the number of prey, density, &/or the space taken by the group had a significant effect on conspicuousness • Also found significant increase in time taken to approach when the group was less dense, with approach time declining with increasing density of the group • Larger Daphnia swarms more conspicuous to stickebacks • Targeting error increased with local density

SA3: Identify and describe the research on the effect of prey group size and aggregation on detection, including the methods used and the findings...

• Ioannou et al., (2011) observed the detection of prey chironomid larvae by three-spined stickleback predators when varying group size & number of groups of chironomid larvae prey. • Also used a two-dimensional model based on visual angles • Looked at relationship between distance to prey & total density • Found encounter effect > detection effect • Found higher number of prey groups resulted in a shorter search/encounter time, but encounter time was longer when lower number of aggregated prey groups • Also found larger groups are more conspicuous to predators (than smaller groups as they are further away from predator) • Net affect is aggregation reduces detection

SA3: Identify and describe the research that was an early example of model that considered both predator and prey using free to movement, including the methods used and the findings...

• Iwasa (1982) used model with multiple free distribution across three-trophic levels • In nature use diel vertical migration as Zooplankton move up through the water column as light reduces to feed on phytoplankton to avoid visually hunting predators • Found prey zooplankton respond to food distribution as feed on phytoplankton (non-responsive) & respond to fish predator distribution • But also found results not intuitive as predator tracked the distribution of prey's resources e.g. predators can map onto phytoplankton distribution (not prey distribution)

SA13: Identify and describe the research on the presence of prey in relation to the top predator being rare, including the methods used.... Hint: 📑🔍🇦🇺 ( 🐨 🐻 etc. & 🐕 )(🐑 🐰🐺 🌧⚖)

• Johnson et al., (2007): measured decline extent for all ground-dwelling marsupials on Australia since European settlement & proportion of original range that overlaps with present distribution of high-density dingo populations based on past data • Also looked at proportional overlap of the original range with the present distributions of sheep, rabbits, & red fox, as well as body mass, mean annual rainfall, & predominant habitat etc. • Used least squares regression models with various combinations of variables to predict persistence of marsupials & to select the best performing model • Persistence = proportion of original range still occupied by marsupial species, corrected for body size (which has a big effect)

SA6: Identify and describe the research on the biases in learning as a possible explanation for imperfect mimicry, including the methods used and the findings...

• Kazemi et al. (2014) trained blue tits to discriminate between rewarded & unrewarded artificial prey that differed in colour, shape & pattern • So could use any or all of these three cues • Then tested them with all 3 cues which shared some features of reward & non-reward prey • Found that they used only colour: overshadowing by most salient stimulus (to those birds at that time; needn't always be colour), so imperfect mimic can just mimic colour

SA6: Identify and describe the research that demonstrates that the costs of misclassification are high (thus allowing existence of imperfect mimics), including the methods used and the findings...

• Kikuchi & Pfennig (2009) used artificial snake replicas made from clay (model scarlet kingsnakes) that were accurate coral-snake-mimic, non-mimic, & intermediate phenotypes (AKA imperfect mimics) • placed artificial snake replicas in natural areas & recorded number of attacks (predation events) based on impressions in the clay • Found where coral snakes abundant, intermediate phenotypes survived as well as good mimics; but where coral snakes rare, attacked more than good mimics

SA6: Identify and describe the research on if visual complexity affect habitat choice, including the methods used and the findings...

• Kjernsmo & Merilaita (2012) Used the "least killifish" has horizontal stripes & gave fish a choice been backgrounds under two conditions: predator present or absent • Found they preferred horizontal stripes over vertical when a predator was present, while females preferred complex over horizontal when a predator was present

SA8: Identify and describe the research on the affect of eyespots in fish, including the methods used and the findings...

• Kjernsmo & Merilaita (2017) presented the sticklebacks (predators) with 4 different prey types that had either: no additional mark (control); noneye-like rectangular mark; single eyelike mark (based on perch's eye in lateral view); & two eyelike marks (based on perch's eyes in frontal view) • Found fish took longer to attack prey types that exhibited eyelike marks, than to attack prey types without eyelike marks • "Resemblance to the enemy's eyes underlies the intimidating effect of eyespots"

SA8: Identify and describe the research on if iridescence can be used for a protean response, including the methods used and the findings....

• Kjernsmo et al. (2018): Bees first conditioned to tell difference between artifical target flower shape (oval or circular) in the arena which contained either sweet solution or none • Then used 8 artificial flower tragets (4 oval & 4 circular) with 4 different levels of iridescence (different reflectance levels) that were randomly positioned in an arena & observed visits by conditioned bee(s) • Found that the bees struggled to detect target flowers with diffraction grating & multilayer iridescence, indicating that these impair shape recognition

SA13: Name and describe the conflict between different predator species and its potential impacts, as a form of interference, including an example...

• Known as Intraguild predation (IGP) • Extreme predator-predator interference • Most studied, probably most common form of interference (& very common in natural ecosystems) • IGP: interspecific predation between carnivores that compete for the same prey • Combines both processes of predation & competition • Effects can be direct predation or through indirect effects • E.g. both the sea lion & shark compete for the same prey (e.g. fish), but the sea lion can also kill & consume the shark • Has important implications for conservation

SA8: Explain the concept of a "perceptual bottleneck", including who the idea is by...

• Krakauer (1995) • Can only focus attention on one (or a very few) targets at once • Attention spotlight

SA11: Identify and describe the research on the affect of reduced prey activity in guppies, including the two different experimental methods used and the findings...

• Krause & Godin (1995): simultaneously presented individual cichlid fish with two equidistant guppy shoals which differed in size • Recorded which of the two guppy shoals was 1st attacked & how often each shoal was attacked by the cichlid during a 3-min period • Shoal size had a significant effect on % of time cichlids spent near guppy shoals & on % of their attacks directed at the larger shoal • Found larger groups preferential to attack • Tested the influence of guppy activity on the shoal choice of cichlids, by exposing guppy shoals to different water temperatures (one guppy shoal was kept at 24-26˚C & the other at 15˚C) • Recorded guppy activity for both temperatures before presenting two groups of guppies of varying sizes from both the temperatures to cichlid predator. • Recorded which of the two guppy shoals was 1st attacked & how often each shoal was attacked by the cichlid during a 3-min period • Found guppies moved significantly more & showed a higher frequency of rapid turns when in warmer water compared with the cold water treatment. • Found cichlids had a significant preference for the smaller shoal when they had come from warm water • Found reducing water temp = reduced activity & reduces preference for larger prey groups

SA11: Identify and describe the research on prey feeding posture, including the methods used and the findings...* *

• Krause & Godin., (1996) • Prey less likely to detect approaching model predator when in vertical feeding position • When detect predator further away, difference between initial reaction & flight • Binary choice experiment • Feeding postures preferred by predator (same trend with % attacks & % time) • vertical feeding posture of prey preferred by predator -> attack these fish • Not much preference when horizontal posture • Free interaction experiment - > prob capture high when feeding in vertical posture

SA12: Identify and describe the research on the reasons why snowshoe hares have cycles of population density changes, including the methods used and the findings... Hint: 🐇+🍃 ✓🐱 vs ⦙_ 🐇 _⦙ ✗🐱 vs ⦙_🐇 + 🍃_⦙ ✗🐱

• Krebs et al., (1995) long term (8 year) study which used two control treatment areas & three experimental treatments: 1. area with additional food 2. area with an electric fence to exclude predators 3. area with both additional food & an electric fence to exclude predators. • Capture, marked, & released snowshoe hares to estimate population densities, & also used radio collared hares to determine survival rates • Found when no predators found there was a 2 times greater hare population density (than in control) • Found for more food there were 3 times greater hare population density (than in control) • Found for both more food & no predators there was a 11 times greater hare population density (than in control) • Indicates synergistic effect & suggests that three-level trophic interactions are important

SA10: Explain the possible reasons behind why Blue Whale individuals show different lateralized feeding strategies depending on where and how that behavior is performed...

• Krill patches are smaller & less dense at the surface, & more acrobatic manoeuvres (barrel-roll) are required to capture these • The right eye is connected to the left hemisphere of the brain, which is involved in planning & coordinating actions • Whales rolled to the left allowing them to see prey with their right eye - 360 degree left to get whole krill shoal in mouth → link to brain → cognitive mechanisms to predict where prey will be → beneficial • At depth → move through large shoal to get as much as possible → role right → get more Krill • These movements may be important at this size where movement takes longer and there are limits to sensory transduction • Unclear why whales predominantly show right-sided lateralized feeding behavior at depth

SA9: Identify and describe the research that demonstrates how colour via the oddity effect aids predators, including the methods used and the findings... Hint:

• Landeau & Terborgh (1986): used two groups of Bass each fed daily either brown (natural) or blue minnows (dyed using Nile Blue) • Bass exposed to schools of 8 minnows containing 1, 2, 4, 6 or 7 'odd' fish, ('odd' being fish colour that bass didn't normally eat) in yellow wading pools (both fish colours conspicuous) & blue pools (natural fish conspicuous) • Recorded the number of attacks, the capture time & the minnow colour (for attack & capture) • Found that bass preferentially attack & kill odd prey without bias to odd prey colour phenotype - indicates its easier to target odd coloured prey

SA8: Identify and describe the research on the startle displays of cuttlefish, including the methods used and the findings...

• Langridge., (2009): used naïve juvenile cuttle fish inside a plastic box within a tank & released a predator into the tank (either a juvenile sea bass, juvenile dog fish or crab) & filmed the cuttlefish behavioural response to the predator • Found that large predatory fish never elicited the complete deimatic display i.e. didn't result in startle display behaviour by the cuttle fish • Suggests that cuttle fish may only use startle /deimatic displays to scare off small fish to avoid competiton for food as well as costs of potentially harmful interactions

SA11: Describe the use of group living, as well as identifying and describing some research on optional spacing trade offs, including the methods used and the findings....

• Larger groups are more conspicuous • Also shows trade-off for predator as what is conspicuous may not be easy to attack • Ioannou et al., (2009) observed Daphne being attacked by Sticklebacks • Found denser prey preferentially attacked by predator, but prey further away, so harder for predator to attack as targeted less accurately

SA10: Describe the feeding behaviour of the blue whale....

• Largest animal that ever lived, meaning they need to be very efficient hunters to meet energy requirements • Before opening their mouths to capture prey (krill) they roll on their longest axis • Two types of rolls are seen: 1) small 'side-rolls' - whale rotates <180˚ in one direction during the lunge & then rotates the opposite way 2) large 'barrel-rolls' - unidirectional roll past the 180˚ rotation

SA1: Describe why do predators persist when there is 'the life-dinner principle'...

• Life-dinner principle (Dawkins & Krebs., 1979): Predators are fighting for a meal, the prey is fighting for its life. • Might expect prey always win but doesn't happen. • Prey should always win the arms race because of the life-dinner principle.

SA11: Describe feeding posture in relation to limited attention...

• Limited attention can be exploited by predators - direct cost of feeding • Posture of prey when feeding affects predator detection • When eating they don't respond to predator as quickly (predator gets closer)

SA11: Define and describe Trade Offs

• Limited resources, including time • All adaptations have some cost, reducing resources for other things • Far more widespread than just PP interactions • E.g. Choices between foraging, mating territorial defence, vigilance for predators

SA8: Describe the startle displays of the Frilled dragon and Spinx moth, including if these are actually pure startle displays...

• Lizard sticks out/expands its colourful neck frills at predators - however it bites too so could be considered aposematism • Moth has brightly coloured hind-wings which are revealed when disturbed - however has cryptic forewings so could be Batesian mimicry

SA12: Describe if there is much evidence for these different functional responses, including the research from Moustahfid et al., (2010)....

• Loads of it - mostly small scale, especially lab studies • Study looked at a total of 7 piscivorous fishes & 4 prey species that vary by morphology & behavior • Restricted analyses to predator-prey combinations where a reasonable number of observations (i.e. stomach contents for a species) were available • Found Silver hake per capita consumption increased with increasing prey densities until it reached a maximum level - aka type I • Found Atlantic cod per capita consumption increased with increasing herring density until it reached a threshold above which the per capita consumption become constant - aka type II

SA8: Identify and describe the research on if colour change (as a protean response) fool predators, including the methods used and the findings.... Hint:

• Loeffler-Henry et al. (2018) used human participant who (on a computer game) had to track & capture targets on complex backgrounds • Single square prey item placed at random position on a complex background (grass or sand) • When subject moved mouse, 'prey' 'escaped' & would either stay same cryptic colour, or flash red (intermittently or continuously) then move, the subjects then had to search for the prey on a new screen • Found that flashing red prey (especially intermittently) survived better than those that stayed same colour both on grass & on sand

SA13: Identify and describe the research on the potential importance of predator-mediated coexistence in terms of marine conservation, including the research methods used... Also describe the various findings of this research, including what these findings indicate... Hint: ↑🐠 & ↑🐟 __✽⃣___❀⃣__ 📝 𝐕𝐒 ↓🐠 & ↓🐟 __✽⃣___❀⃣__ 📝 ↑🐠 & ↑🐟 = ↑✽✽ ↓❀❀ 𝐕𝐒 ↓🐠 & ↓🐟 = ↓✽✽ ↑❀❀

• Loh & Pawlik., (2014): surveyed sponge communities (e.g. defended & palatable) & spongivorous fish (e.g. parrotfish & angelfish) populations on overfished & less-fished (marine protected area) Caribbean reef sites & compared sponge assemblages across all survey sites • Recorded sponge species & occurrence within five 1x1m² quadrats along a 20m transect line, with 5 transects surveyed per site. • Found significant differences in sponge communities (assemblages) as protected areas with many spongivore fish had high levels of defended (rare) sponges (e.g. >90% of sponge cover), while in contrast the majority of overfished reefs had high levels (>50%) of palatable sponges • Found significant relationship between spongivorous fishes & palatable sponges for all sites, with a negative correlation between abundance of consistently undefended sponges & the total number of predators. • Indicates sponge communities depend most on abundance of sponge-eating fishes, as direct correlation with spongivorous fish abundance & type of sponges in community • Indicates sponge predators are beneficial by mediating/reducing competition between prey species (for space) via consuming faster-growing palatable sponges, which allows endangered reef-building sponge/corals to recover, thus removal of predators via overfishing causes greater competion & hinders the recovery of endangered corals

SA11: Describe the later research by Endler in 1980, including the methods used and the findings...*

• Long term artificial selection experiment in pools varying predation risk, control = no predators • Founded with guppies from many locations mixed • Found decline in conspicuous eye spots with dangerous predator • Also found males adjusted behaviour based on risk

SA2: Describe the random movement for Lévy versus Brownian (Diffusion) as demonstrated in the research by de Jager et al., (2013) on mussels....

• Lévy has skewed distribution & most step lengths small, few very large - 4x longer step lengths (long tail distribution), jump into different area then move a little in that area • Brownian had more even distribution of step lengths (drawn from normal distribution), less variability with average step lengths (normal distribution) • More ground covered by Levy walk - "super-diffusive"

SA11: Identify and describe the research on vacation in activity in response to predator density, including the methods used and the findings...

• Macchiusi & Baker 1992: varied density of predators & observed activity of prey in small tanks, also varied the time predators were present from 0% to 100% • Found larvae responded very strongly to the presence of fish predators by staying in tubes longer when % of time that fish are present increased & that larvae activity outside of their tubes dropped as the time predatory fish were present increased • Found reduction in activity of larva when density increases → prey still do minimal activity to get food • Effect of predator density saturates at non-zero - important as there is a minimum activity once starvation is a threat

SA11: Describe the trade-off with attracting a mate for the Guppy fish....

• Males brightly coloured, courtship display to females • Brighter & darker colours, & eye spots, a signal of better mate quality to females • But more conspicuous to predators e.g. pike cichlids - the major guppy predator in Trinidad (a specialist guppy hunter)

SA6: Describe the later research by Skelhorn & Ruxton (2010) on the use of masquerade, including the various methods used and the findings...

• Manipulated early encounters of chicks as groups encountered either a Hawthorn branch with leaves or a manipulated Hawthorn branch bound in purple cotton thread • Gave five different test stimuli of either: a single twig; two twigs; a single caterpillar; two caterpillars; & one caterpillar & one twig • Five different stimuli given to two groups, one that had ecountered manipulated branches vs one that encountered unmanipulated branches Here, direct comparison is possible • Found chicks trained with unmanipulated twigs took a significantly long time to investigate/attack caterpillars when no twigs & when twigs on own • Thus found chicks were faster to attack caterpillar first when both caterpillars & twigs were present together, so caterpillars benefits less from masquerade when found alongside their models • Indicates better for catterpillar to be viewed on own as chick can compare masquerading caterpillar to twig & realise differences

SA7: Identify and describe the research on naïve predators, including the methods used and the findings...

• Mappes et al. (2014) put out model wood tiger moth larvae in different fields throughout year • Then put out fake pastry caterpillar which were black (cryptic) & 2 aposematic forms: small orange dot & large orange splodge • Found Aposematic forms survive better early & late in season • Foud Cryptic forms survive better in mid-season when naïve birds fledge

SA10: Identify and describe the research looking at the speed of Sailfish, including the methods used, the findings and what this indicates...

• Marras et al., (2015) they measured swimming behaviour of sailfish using high-speed video & tri-axial accelerometery • Showed that sailfish do not exceed speeds of 10m/s during predator-prey interactions • Suggest that extension of the dorsal fin may improve control of the bill & minimise yaw • So, sailfish may rely mainly on accuracy of movement & the use of the extensions of their bodies rather than using high speed to chase evasive prey

SA6: Describe masquerade compared to Batesian mimicry the and also describe the debate/argument on if masquerade is 'just' Batesian mimicry, including some different examples for each...

• Masquerade is gaining protection by looking like something which predators ignore • Batesian mimicry is gaining protection by looking like something which predators avoids • E.g. Pearly Wood-Nymph moth (Eudryas unio), looking like bird droppings so predators could be ignoring or avoiding poo • Ruxton et al., (2018) say masquerade is 'just' Batesian mimicry, & that Batesian mimicry may evolve from masquerade • Slide 21 • Henry Walter Bates (1825 - 1892) looked at Heliconium butterfly which are toxic due to glycosides in their food plants, while Dismorphia species (Batesian) mimic them but are non-toxic so don't get eaten • Possibly environment explains similar distribution

SA5: Identify and briefly describe the research testing Cott's ideas, including the findings...

• Merilaita (1998) tested colour pattern of marine crustacean; by looking at contrasting colour pattern intersect body edge • Looked at males & females, how much of edge intersected • Found spots intersect the margin more often than expected by chance

SA4: Identify and describe the research on the use of "Compromise crypts" by prey, including the methods used and the findings...

• Merilaita et al. (1999, 2001) looked at tits foraging for prey on 2 artificial backgrounds; different artificial prey (specialist, generalist (Compromise crypsis) etc.,); • Found specialists only do well on one but generalists (Compromise crypsis) did better on average on both backgrounds than either specialist (in this situation) • Matching more than one background quite well might sometimes be better than matching one background very well • cf specialism vs generalism in ecology

SA4: Describe the conclusion that can be made from Michalis et al. (2017) in terms of crypsis...

• Merilaita et al. are right; Endler is wrong • Not all random samples are equally cryptic • It's best to be the commonest type of background sample

SA5: Describe Countershading including Thayer's theory about this...

• Method of camouflage in which an animal's coloration is darker on the upper side & lighter on the underside of the body, this pattern is extremely common (e.g. sharks, deer, penguins) • Thayer's theory is that it functions to obliterate shape-from-shading cues (although this isn't necessarily correct).

SA4: Identify and describe the research investigating the best background sample to be for moths, including the various methods involved in this and the findings...

• Michalis & Cuthill et al. (2017) took calibrated photos of 100+ oak trees & took >500 moth-sized samples from these • Quantified the colour in 3 dimensional bird colour space (4 spatial frequencies + 6 orientations) • Created artificial moths from paper with these patterns, & an edible mealworm 'body', with a 2x2 design of common vs rare colours, common vs rare textures • Put out 100s on oak trees & monitored their 'survival' over 3 days • Did an equivalent experiment on humans searching for pictures of the artificial moths on computer screens • Found the commonest colours & textures survived best, while the human results were similar as commonest colours & textures took longer to detect • Also found if the colour was rare, texture was unimportant, while if the colour was common, then having a common texture was important

SA11: Identify and describe the research on limited attention, including the methods used and the findings...*

• Milinski & Heller., (1978) • Fish favour higher density prey when predators are absent graphs • Shows flexible adaptation of feeding behaviour to risk • Smaller group → more likely to detect predators • Prey respond depending where they are foraging • Use diff densities • Pred present → prey pref low density group • No pred → prefer high density

SA9: Identify and describe the research on hunting experience possibly reducing the confusion effect, including the methods used and the findings...

• Milinski (1979): Fed 50 Daphnia to one group of Sticklebacks & fed 5 (10 groups of 5) Daphnia to another group, so had Sticklebacks with vs. without experience of large prey groups • Then carried out trials with 1 x 50 Daphnia, 10 x 5 Daphnia, & then 150 Daphnia in trial • Used infrared beam to detect speed & measure latency times as breaking 1st beam started the clock & interrupting the 2nd beam stopped it • Found inexperienced fish hesitated before first attack, had reduced rate of attacks & stopped feeding earlier compared to the experienced fish, so indicates that experience alleviates the confusion effect

SA5: Describe the idea by Cott (1940) in terms of the use of disruptive coloration (vs background matching) by humans, including the key features involved...

• Military used DPM (Disruptive Pattern Material); disruptive coloration involves: • Colour patches intersect the body's outline • Differential blending - some colour patches match the background, some don't • Maximum disruptive contrast - adjacent colour patches have • high contrast so they don't look they belong to the same thing

SA7: Define and describe Mullein mimicry, including an example to illustrate how it can be beneficial...

• Mimicry between species that are both defended • "defended species may evolve a similar appearance so as to share the costs of predator education" Müller (1879) • The first model of frequency-dependent selection (one of the first mathematical models in evolutionary biology) • E.g. warning butterfly species; toxic species mimic each other, so share the cost of predator education, so both species benefit-frequency dependent selecting • Rings are a common feature as get many species mimicking each other (match in some locations)

SA9: Identify and describe the research on Dragonflies Intercepting prey, including the methods used and the findings...

• Mischiati et al., (2014): used dragonfly "hotel" to elicit predatory behaviour (including pond) to replicate natural environment (common in studies of insect behaviour in the lab to have to recreate suitable, 'natural' conditions to elicit behaviour) • Tracked the 3D position & orientation of dragonfly head & body during flight using retroreflective markers & tracked 3D position using cameras • Found no evidence for constant bearing / parallel navigation • Found initial movements more complex than single strategy, with changes in body orientation & then stereotype behaviour when close to prey • Counter-rotating head allows this to happen as the animal maneovers its body into the position needed to make the final interception (which is stereotyped) i.e. move head to keep prey in same visual field - like pure pursuit (in falcon example)

SA6: Describe Hoverflies as an example of an imperfect mimic, also identify and describe the two pieces of research on the Hoverfly as an imperfect mimic, including the different methods used and the findings... Hint:[🐝] + 🐦

• Most hoverflies are wasp- or bee-like at first glance, but they lack long antennae, lack a proper 'wasp waist', have only one pair of wings, & fly very differently. • Dittrich et al. (1993) trained pigeons to discriminate photos of wasps from non-mimetic flies, & then gave them hoverfly pictures to classify • Based on pecking frequency found the Pigeons rank the two commonest hoverflies as very similar to wasps • Bain et al. (2007) used artificial neural networks trained to discriminate wasps from non-mimetic flies, and then gave them the same hoverfly pictures used in Dittrich et al. (1993) • Found results from the AI network were very similar to those from the pigeons

SA4: Describe the different methods used by prey to conceal motion, including some research that supports this...

• Move so slowly that you're not detected • Move in short bursts so that you're not detected • Match the motion of the background • Or give up & use a different tactic • Peters et al. (2007) looked at Jacky dragon • Found when displaying, move in a pattern that has different motion characteristics from the background vegetation

SA1: Describe the survivability onion for prey... Hint: 1 ( 2 ( 3 ( 4(5(6)5)4 ) 3 ) 2 ) 1

• Multi-layered: 1) Don't be there AKA encounter, 2) Don't be seen AKA detection, 3) Don't be targeted AKA recognition, 4) Don't be hit, 5) Don't be penetrated, 6) Don't be killed • Predator get through layers

SA13: Identify and describe the research on the cascading effects of the loss of apex predatory sharks from a coastal oceans, including the different research methods used, the various findings and what these findings demonstrate... Hint: 💻<(📑) = 📉↓~~~⊿~~~~ → 📈↑🔷〰️ →📉↓🐚

• Myers et al., (2007): analyzed 17 research surveys that recorded elasmobranch species from U.S. coastal waters over 35 years • Focused on 11 great sharks & 14 other elasmobranchs (rays, skates, & small sharks) • For each elasmobranch modelled population trends in data sets & used these trends in a meta-analysis to work out estimates of rates of change • Elasmobranch relative abundance trends were estimated by fitting generalized linear models to each survey • Found declines in 7 great species e.g. 93% for blacktip sharks, ~97% for tiger sharks & by 99% or more for bull, dusky, & smooth hammerhead sharks • Found trend of decreasing great shark abundances, & declines in mean lengths of sharks such as blacktips, bull, & tiger sharks of 17 to 47% • Found (from meta-analyses) increases for 12 of mesopredatory elasmobranch prey species, including a strong increase in the cownose ray • A hyperabundant cownose ray populations can consume a large quantity of bi-valves, with increased predation possibly inhibiting recovery of hard clams, soft-shell clams, scallops & oysters • Shows top predators indirectly support species populations further down food chain by limiting the population sizes of their predators, so without top predator → collapse of fishery due to negative impact on scallop population

SA12: Describe the research findings by Sheriff et al., (2009) for the natural observations and exerimental treatments, including what this could indicate in relation to the snowshoe hare population... Hint: 🏞 1st 🍼 = ↑😨, 2nd 🍼 = ↓😨, ↓🍼 = ↑😨 🏢🐇<(😨) 🐕 = ↓🍼(⚰), 🐇<(😊) = ↓😨 vs 🐇<(😨) = ↑😨, 🐇<(😊) = ↑⚖🍼 vs 🐇<(😨) = ↓⚖🍼 ∴🐇<(↑😨) = ↓🍼(⚰) + ↓⚖🍼

• Natural observation found FCM concentrations in dams decreased 52% from 1st litter to 2nd litter across the three years, & that litter size was 19% smaller in 1st litter compared with 2nd litter & litter size was negatively correlated to FCM concentrations in dams • Experimental method found stress treatment had negative correlation with litter size as only 9 out of 14 stressed hares gave birth to viable young, while control dams had FCM concentrations 54% & 89% lower than stressed dams • Also found stressed dams produces smaller litters, with the controlled dams offspring being 58% greater body mass compared with stressed dams offspring • In summary higher stress (cortisol) caused smaller litter size & smaller offspring mass, in both observation & experiment • Thus lower reproductive output & population sizes at ecological scale, indicates that possibly fear rather than direct lethal predation drives the lynx effect

SA11: Describe the trade-offs across contexts in term of are animals just predators or prey...?

• No - so more common than trade-offs within contexts • Potential contexts: predation, feeding, mating, caring for young • Growth trade offs etc. linked to predator-prey trade offs

SA7: Discuss if kin selection the only way toxic defences could evolve, including some examples to illustrate this...

• No as if the individual has a better chance of surviving as a result of the defence, individual selection is sufficient • E.g. toxins often in detachable items (e.g. spines) & toxic animals often have tough cuticles & can survive attack • However on a cellular/genetic level it's all kin selection in the end • E.g. plant cells die when eaten (toxicity) these cells are related to cells in the reproductive system

SA2: Describe the encounter situation in terms of predators and prey...

• No encounter or encounter occurs • When all else being equal the predators maximise the encounter, while the prey minimise the encounter • Common principle of predators trying to minimise/maximise one thing & prey trying to do the opposite

SA1: Describe the issue with focusing on the Domains of danger (DOD), including other research methods to look at this and what is required to understand the effects of the domain of danger...

• No test of whether DODs are really the predictor for predation risk • Others seek the best movement rules that reduce the DOD the most. • Some even assume the predator acts like Hamilton's assumptions & then sees how prey aggregation would evolve, e.g. what kind of social rules the prey would have. • A small number test whether predators attack the edges of groups / nearer prey / those more widely spaced, providing probably the closest test of the predator's behaviour with respect to the theory. • Need to quantify DODs for prey, see which one is attacked, & then show the DOD is a better predictor for risk than other measures of spatial position.

SA8: Describe the difficulty with determining if a startle display is pure, and why the display is still useful...

• Not necessarily easy to isolate a 'pure' startle effect from other effects of the pattern • But the predator's startle response has evolved to avoid danger rapidly, & that includes dangerous animals • So the concept of a startle display (exploiting innate withdrawal reflex) is still useful

SA5: Describe the observations by Cott that lead to the idea of Coincident disruptive colouration...

• Noted that the colour patches of some frog's legs "line up" • Couldn't be a simple accident of development, must be natural selection • Reasoned that this would make salient features like legs less recognisable e.g eyes have band (dark line) to reduce recognition

SA4: Describe the use of search patterns as noticed by Luuk Tinbergen, including what this could be...

• Noticed that rare prey were under-represented & common prey over-represented in the food great tits brought to their chicks • Tinbergen proposed that birds had to learn the patterns of cryptic prey & needed frequent encounters to do so • Need to "get their eye in" as its a short-term perceptual filter

SA3: Describe the research by Clua & Grosvalet., (2001) as an example of the use of social cues (social information) by predators...

• Observational study of predators visiting bait balls in Azores • Regular ordering of species arriving & participating • Common dolphins start circling prey, then other species join in - use cue of dolphin • Also applies to foragers more generally, not just predators

SA1: Explain why prey don't evolve to run or fly faster, have bigger horns, have more armour, be more toxic, be more vigilant, live somewhere else, be more camouflaged, be less nutritious, etc....

• Often too costly e.g armour heavy so can't run as fast to escape etc. • Trade offs between surviving predator & other factors e.g mating success, grazing etc.

SA14: Identify and describe the research on frequency dependent survival of a certain fish species, including the methods used and the findings from this research....

• Olendorf et al., (2006): conducted mark-release-recapture experiments & captured guppies were separated by sex and kept in aquaria • Marked anaesthetized fish with a small tattoo unique to each experimental pool - used only white or black tattoos to avoid colours implicated in female choice • Males were sorted into 'Coloured' & 'Uncoloured' phenotypes, each male was digitally photographed before release but after marking. • Manipulated the frequencies of males with different colour patterns in three natural populations to estimate survival rates • On recapture males were anaesthetized & photographed again • Used repeated-measures analysis of variance (ANOVA) of recapture rates • Found that rare phenotypes had a highly significant survival advantage compared to common phenotypes, as males with the rare phenotype had significantly higher recapture rates • Experiment demonstrates that frequency-dependent survival occurs in natural guppy populations

SA13: Identify the research and describe the findings for this research on the intraguild predation patterns of mammalian predators....

• Palomares et al., (1999): carried out a literature survey of mammalian carnivores • Found positive significant relationship/correlation between the body masses of solitary killer species & body masses of their victim species • Found social species kill larger species victims than solitary species • Found interactions & consumption increases when shared prey species (food) is scarce or disputed. • Found victim species may alter their use of space, activity patterns, & form groups (in response to killers) - these trends mostly follow patterns seen in standard predator-prey pairings • Found this is a big source of mortality for African wild dogs (~50%) & Cheetahs (68%) which are killed by other predators like Lions & Spotted hyenas

SA13: Identify and describe the research on heterospecific social learning of novel prey cues, as an example of interspecific learning between predator species, including the methods used (as well as why they were used) and the findings... Hint: ⦅\☃/⦆ <(🎓) + ⦅\☃/⦆ <() vs ⦅\☃/⦆ <(🎓) + (\☃/) <() vs ⦅\☃/⦆ <() vs ⦅\☃/⦆ <() + (\☃/) <()

• Patriquin et al., (2018): measured learning rate for substrate-gleaning bats to associate the novel cue (based on katydid prey call frequencies) with palatable prey in four possible treatments: 1. Conspecific social learning: bats trained to the novel cue to serve as a model for same species of naïve test bat, each test bat that successfully learned novel cue became model for subsequent test bat, resulting in a transmission chain. 2. Heterospecific social learning: bats trained to the novel cue to serve as a model for a different species of naïve test bat (didn't use transmission chains due to space, time, & capture constraints.) 3. Trial-&-error control: single naïve bat was present, but no trained model - control for possibility that bats can learn novel cues through individual learning as readily as from conspecific or heterospecific models. 4. Social facilitation control: both bat species were present & naïve - control for possibility that presence of conspecifics or heterospecifics, even if inexperienced, somehow motivates learning. • Found bats learned novel cue from conspecifics significantly faster than through trial & error or through social facilitation • Also found bats learned to associate the novel cue with food significantly faster from the heterospecific than through trial & error or through social facilitation • Found no significant difference in learning speed between conspecifics & heterospecifics.

SA9: Identify and describe the research on colour as an oddity effect, including the methods used and the findings...

• Penry‐Williams et al., (2018) experimentally manipulated prey colour by dyeing Daphnia red or black, & used fish predator (kerri tetra) • Predator in tank randomly subjected (in a random order) to the following groups of prey: red oddity (red 1 : 9 black), black oddity (black 1 : 9 red) & in equal ratio (red 5 : 5 black). • Recorded time taken for first predation event to occur & the colour of the attacked prey • Found predators preferentially attacked odd prey, but doesn't impact latency to make attack

SA2: Describe how Sit-and-wait, 'ambush' and active search are not as clear cut as they may first appear by using examples to illustrate this...

• Pet cats actively such by ranging around, but once they detect prey, use an ambush strategy - this isn't the same as sit-&-wait. • Lions use ambush to minimise detection of predator to maximise attack success • Associated with sit-&-wait, but also can be part of active search predation, & pursuit by these lions

SA5: Identify the issues with phase mismatch and what could be done to prevent this...

• Phase mismatch can reveal your presence & shape even if colours match (e.g. chequer board pattern) • So may instead hide your background as opposed to your surface • Thayer (1909) "ruptive colouration", now called disruptive colouration, uses contrasting patterns to disguise ones outline

SA7: Describe the affects of ancestral threats and innate fear in humans, including the findings from research on this as an example...

• Phobias tend not to concern present-day dangers, but ancestral threats • Hoehl et al. (2017) found increased pupil dilation in 6 month old infants when shown spiders vs flowers & snakes vs fish (matched for colour & size) • So pupil dilates more with dangerous species.

SA8: Describe when fighting back is an option for prey (including some examples) and what is the impact of this on predator behaviour....?

• Physical fighting -> prey is large relative to predator & often weaponised e.g. buffalo • E.g. Alpha baboon fight/scare off leopard • The effect is to reduce prey profitability • So the predator switches to other prey before completing the attack (go for one that won't fight back) or, better still, before initiating the attack

SA4: Identify and describe the research on the use of search patterns, including the methods used, the findings and what could be suggested from this...

• Pietrewicz & Kamil (1979) trained blue jays to search for moths on pictures of tree bark. • Two species of cryptic moth presented either: one type alone, or both intermixed • Birds detected moths better when only one type, and got better when there was a long run of 'moth present' slides (cf absent) • Slide 45 • If predators can learn to look for a particular pattern then there may be frequency-dependent predation • So being a rare pattern will be beneficial

SA14: Describe thanatosis AKA tonic immobility...

• Playing dead is used as a secondary defence • Usually a state of rigid immobility or catatonia seen under situations of extreme predation threat or stress. • It is observed in many different taxa (e.g. possum), but has not been rigorously researched. • Whether it works (i.e. improves the prey's chances of survival) has not really been studied quantitatively. • How it might work, if it does work, is also a matter of speculation, with no single accepted answer • Maybe learnt or innate, with length of thanatosis possibly being related to stress levels

SA2: Describe the results of de Jager et al., (2013) when comparing Lévy versus Brownian on plotted graphs and how these were interpreted.... Hint:

• Plot log Complementary Cumulative Distribution Function (CCDF) against log step length • On log scale for Lévy the line is straight, while for Brownian it tapers off (I.e. it's a curved line) • y axis shows what proportion of all the data is at least as large as the value on x axis (in this case max step length) • So always largest in top left, & then has to decrease (negative relationship), but the shape of the line is important to test for types of distributions. • Straight line = negative distribution • Curved line = Brownian motion - high density

SA1: Describe the Selfish Herd (Hamilton., 1971) as an example of bias in behavioural literature toward prey behaviour...

• Predator appear anywhere & attack nearest prey -> prey minimise area around them by being in group of prey animals - > less danger • Can explain aggregation of prey simply by prey moving so that another prey is likely to be closer to a predator that can appear anywhere

SA3: Describe the use of auditory cues by predators, as well as describing research on this, including the methods used and the findings....

• Predators may eavesdrop on auditory signal to find prey • Haff & Magrath (2011) used playback experiments of recordings from the offspring of white-browed (fairy) scrubwren, which live in cryptic nests (I.e. nests are well camouflaged) • Found playback increase predation risk • Also found nestlings reduced calling when detected predators nearby

SA6: Describe how mimicry first evolved...

• Presumably evolved from a camouflaged form (so well adapted), so a mutation that makes it a bit like an avoided model will be less well camouflaged/ more conspicuous & also an imperfect mimic

SA3: Describe the use of Area Restricted (Concentrated) Search by certain predators...

• Previous experience (detecting prey) to maximise further encounters with prey • Originally called 'Restricted', but later argued it should be 'Concentrated' as the searches are not entirely focused in a restricted area. • Once food encountered or consumed, predator stays in area - but no cues from remaining prey needed • Shown in crows & sticklebacks • Here, 'some information' comes from memory.

SA1: Describe the costs of overcoming anti-predator adaptations, as well as research on this as an example, including the methods used and the findings...

• Prey evolve grouping via a confusion effect • Predators can concentrate attention on prey • But, increase cost of not being able to detect their own predators • Milinski., (1984) predicted if predator (model) detected, sticklebacks should hesitate to attack the next prey. • Sticklebacks are prey for other animals (eg kingfisher) so detect predator model indicates should slow down prey consumption • Small tank with stickleback eating daphne, with control of cryptic (white) & none • Found the fish can detect the cryptic predator when attacking small groups, but not when attacking large groups - cost trade off

SA2: Describe an example from Trinidad to illustrate how not all habitats have encounter rates issues....

• Prey fish (guppies) are frequently found in river pools & usually at high densities (video via GoPro) • Thus they are always encountered by predators such as Cichlid fish. • Guppies always in field of view of predator as water very clear.

SA3: Describe how there can be selection for prey to be dispersed over space, including some examples...

• Prey should select for dispersion • Cryptic prey - low detection rates • Unresponsive prey - can't flee/avoid after detection or after another is detected

SA2: Describe the Sit-and-wait predators including a pro and con...

• Pro: minimal energy expenditure (vs searching) • Con: requires prey that move (less flexible) • Predator detects prey first as selection pressure to avoid being detected (cost) so can attack unaware prey so they can't escape • Avoid detection &/or recognition e.g. via camouflage, mimicry etc.

SA8: Identify and describe the research on how some eyespots may deflect attacks rather than intimidating predators, including the methods used and the findings....

• Prudic et al. (2014) used the squinting bush brown butterfly (Bicyclus anynana) using the dry season (DS) form that lacks eyespots & the wet season (WS) form that has eyespots • Used a repeated-measures design where each mantid encountered both WS & DS butterflies in random order in an arena & recorded the attack locations on the butterflies • Found WS butterflies were easier for predators to detect (so some cost), but harder to capture & more likely to escape with eyespot damage as predators attacked less important parts of the body as deflection mark draws predator attention away e.g. attacked outer wings for WS butterflies (instead of head) • Also found WS butterflies survived longer, laid more eggs & suffered more hindwing damage (than DS) when mantids were present

SA6: Identify and describe the research on the use of Batesian mimicry to mimic Coral snakes, including the methods used and the finding...

• Rabosky et al. (2016) Used phenotypic classification as classified snake colouration to create a list of conspicuous red-black banded mimics in New World (aka Americas) & snakes in Old World • Also used phylogenetic tree as reconstructed ancestral character states, & tested the spatial relationship between coral snakes & their mimics (across the geographic ranges) to see if similar distribution of mimic snakes to coral model • Found spatial distribution of the mimics is correlated with that of the coral snake (putative) models • Found Coral snakes are sufficiently nasty that for every coral snake species in a location, two (or more) mimic species can be 'supported' i.e. high frequency of mimics supported • Ancestral state reconstructions using phylogenic analysis showed that the red-black banded colouration has evolved independently in different species at least 26 times • Also showed that the mimics evolve after arrival of the models in an area

SA5: Identify some animal species that use a form disruptive colouration...

• Rattle snake, Lime hawk moth, clown fish, crustacean Baltic isopod (Idotea balthica) • All these species show edge enhancement • E.g. white part of clown fish matches coral (foreground) & back ground matches other coloured parts

SA3: Describe the ways that predation rate in terms of the reaction distance i.e. detection, can be considered based on the variations in prey size...

• Reaction distance of predator is relative to the size of the prey e.g. if small prey then needs to be close to predator but if larger prey then has equal reaction distance (to small prey) when further away • Can use models & experiments consider both distance, object size & fish visual acuity in prey selection (e.g. for zooplankton feeding) • Integrates both using a single mechanism (angle subtended by prey) • Can be based on size & population density

SA6: Describe the research by Lettvin et al. (1959) "What the Frog's Eye Tells the Frog's Brain." as evidence for the matched filter possibly evoking attack (or not)...

• Recorded from a class of neurone in the frog's brain that only responds to moving fly-sized objects • Show a frog a large photo of the background & move this through receptive field - found no response • Move a fly-sized object on the photo (with a magnet) seen by the receptive field - found neurons fire • Stick the fly-sized object to the photo & move it - found no response

SA3: In relation to the findings by Sih., (2005), identify and briefly describe the factors / features that determine the outcome....

• Relative abilities to respond including movement & information • Relative costs of responding including movement & conflicting needs • Relative benefits of responding such as Life-dinner principle, energy state (satiation to starvation) e.g. if prey is starving ignore predator & eat food

SA2: Describe the importance of the question 'what's the best search strategy?' for Active searches, including what could be done by a predator without any information....

• Relevant across ecology beyond only Predator-Prey interactions (e.g. pollination, mating, mutualisms) • Maximise return • With no information, do random walk e.g. step length at time (t) uncorrelated to step length at t+1 • No need to put any cost into non-random walks (e.g. memory to remember the previous step lengths) • But many variants for this: - Brownian motion (diffusion) - Correlated random walk (diffusion but correlated direction) - Lévy flight/walk (optimal method potentially) • Overall, 'best' can depend on many factors

SA3: Identify and describe the research on the use of auditory cues by prey, including the methods used and the findings....

• Remage-Healey et al., (2006) investigated responses of toad fish which produce sound (as they're soniferous) to attract females, but can be eavesdropped by dolphin predator • Used dolphin foraging playback recordings in field & found it reduced calling & elevated stress hormone (cortisol) as toadfish detect dolphins • Shows reciprocal use of acoustic cues from one another - arms race between them

SA7: Describe the key aspects and conclusions in the review by Ruxton & Sherratt., (2006) on the evolutionary order/relationship of aggregation with different defence strategies....

• Research should avoid generalizing too much from one predator e.g. domestic chicks often used in experiments • Researchers should avoid using different concepts of the term 'aggregation' defence generally preceded the evolution of both aggregation and signalling, but maybe alternative routes • Strong evidence from phylogenetic analyses that gregariousness is more likely to evolve in aposematic species than in cryptic ones, although aggregation is not essential for the evolution of aposematism. • Also evidence that aggregation is more likely to occur in defended than undefended species (at least in Lepidoptera) • However, rarity of gregarious species causes issues with phylogenetic analyses to determine order of events - indicates aggregation isn't required prior to defence. • Any species order of evolutionary events will depend on their genetics, ecology, physiology & local conditions plus liklihood of appropriate mutations happening.

SA11: Identify and describe the research on gape size, including the methods used and the findings...*

• Rice et al., (1993) • Large fish safe when a small (gape limited) predator • Outcome depends on predator size: here, larger prey survived less well when the predator was large • Initial size distribution was 50:50

SA13: Identify and describe the two pieces of research on the re-introduction of a certain canine predator in Yellowstone national park as an example of how conserving predators can in turn help vegetation and conserve biodiversity, including the different methods used and the findings.... Hint: 06 = ↓🐺 🔫 → ↑♘ → 📏↓🌳 → ↓🐻⊃ vs ↑🐺 →↓♘→📏↑🌳 +→↑🐻⊃ 07 = ↓🐺 🔫 → ↑♘ → 📏↓🌿 vs ↑🐺 →↓♘→📏↑🌿

• Ripple & Beschta., (2006): used publications, government reports, & available databases to establish historical trends for wolf & elk populations, as well as the status of willow communities • Measured browsing intensity & heights of willow along 3000 m transect by the river • Measured heights of willows that were inside & outside of two exclosures (been there >50 years) • Found when wolves were absent there was unimpeded browsing by elk which suppressed willow communities, which in turn meant Beavers were driven out • Found when wolves present willows outside enclosures had increased in height & had a decrease in % stems browsed from a high of 92% (in 1998) to 0% (in 2002) • Suggests new willows growth (due to wolves suppressing elk) may allow Beaver populations to increase • Ripple & Beschta., (2007): examined a potential trophic cascade involving wolves, elk, & aspen. • Measured the recent history of browsing & height for 5 tallest young aspen in each clone (n = 490) • Found reduced browsing & increased heights of young aspen during the last 4-5 years, particularly at high predation risk sites (riparian areas with downed logs)

SA13: Identify and describe the research on the importance of conserving a certain feline predator in relation to the affects on vegetation and biodiversity conservation, including the methods used and the findings.... Hint:

• Ripple et al., (2006): compared 2 sites where cougar apex predator are common & rare, also obtained estimates of historical mule deer population from Zion Canyon census data • Conducted a survey of fecal droppings along 4000m of foot trails to determine cougar relative abundance & recorded hoofprints within belt transects to determine deer relative abundance • Assessed biodiversity based on relative abundance of selected indicator species & used visual encounter surveys conducted along the banks on each side of the channel • Measured the diameter of all Fremont cottonwood trees & cored some trees to establish age-diameter relationships for estimating ages of uncored trees • Found Cougar density varies because of human visitor density variation, with reduced cougar densities causing higher deer densities, higher browsing intensities & reduced recruitment of cottonwood trees, increased bank erosion, & reductions in species abundance • Found "cougar common" sites had a higher biodiversity & higher densities of other species such as butterflies, lizards, amphibians, woody plants (e.g. willow), & wildflowers • Found low numbers of frogs, toads, & lizards associated with the ''cougars rare'' sites - may be a result of both lower levels of invertebrate prey abundance & degraded habitats

SA11: Identify and describe the research on the trade-offs with searching for a mate, including the methods used and the findings...*

• Rohr & Madison 2001: manipulation of gravid female odour & macerated male newt extract in male red-spotted newts • macerated male newt extract = conspecific alarm substances • Top: avoidance of where odour added. Strong avoidance for predator cue only. Preference with just female odour, but effect cancels out when female cue paired with predator cue (similar average to control). • Bottom: activity. Just high predation cue, lowest activity, but increases when female cue added • manipulate female odour cues & predation risk • When low risk & odour -> pref • When pred & female -> values shift -> male trade off • More activity for odour in low risk • Less when high risk, but more when female odour

SA10: Identify and describe the research on shoal structure in different environments for 3D dimensions, including the methods used, the findings, and what this indicates about the selfish herd predictions... Hint:

• Romenskyy & Herbert-Read, et al., Pacific blue eyes (Pseudomugil signifier) used as prey, while Flathead gudgeon (Philypnadon grandiceps) used as predators • Shoal structure was observed in both horizontal & vertical planes, also used tracking technology to track shoal structure & construct & what structures they from in 3D • Found the fish formed 2 structures in 3D (shown by hot/cold plot): - When the fish shoals were at the surface of the water, they were spread out & they formed a 'carpet-like', flat structure - When the fish shoals were below the surface of the water, they spread out in both planes forming spheroid 3D structures, or 'spheres' • So, at the largest scale, it can be habitat cues (i.e. prey found in certain habitat types) not just cues coming from actual prey individuals • Provides support for earlier predictions, where it was predicted that selfish-herding can result in two types of group structure depending on individuals' location in space, especially in relation to boundaries in the environment.

SA2: Identify and describe the research on when sit-and-wait predator technique is favoured, including the methods used and the findings... Hint:

• Scharf et al., (2006) used simulation model of active & sit-&-wait predators with prey on a donut grid. • Varied properties with predators & prey to look at time to capture (t) • Found increasing detection ranges favour active predators over sit-&-wait predators • When similar speed for active predator & prey then sit-&-wait did better, but when active predator faster than prey the active predator had the advantage • Sit-&-wait had advantage when active predator & prey have less directional movement (more correlated random walk) • But active predator (using direct movement) gets advantage when prey uses random movement (i.e. more random turns). • So advantage of active vs. sit-&-wait depends on properties of predators & prey

SA8: Identify and describe the research on high contrast AKA dazzle camouflage, including the methods used, the findings and what this indicates...

• Scott-Samuel et al. (2011) used human subjects presented with moving dazzle camouflage objects (that were stripes, zigzags & checks) & reported which moved more quickly. • Found complex patterns were perceived as moving more slowly than actually were when judging speed of patterned target relative to plain control • So high contrast ('dazzle') patterns seem to interfere with motion judgements

SA8: Identify & describe the research on the density affect and unpredictability of motion and their impact on confusion...

• Scott-Samuel et al. (2015) used human subjects who had to follow specified target in a swarm of similar targets • Both density, number, & predictability of motion, varied independently • Targeting error was recorded as the distance in pixels between mouse clicks & target centre • Found more wiggly motion = lower hit rate, so unpredictability of motion increased confusion • Found density affect targeting rate, so density, not number, drove the confusion effect • Interaction between density & unpredictability of motion • Unpredictability increases targeting error for all group densities, but the magnitude of the effect increases at low-to-medium densities

SA12: Identify and describe the research on stress in prey as a sublethal effect of predators, including the multiple different methods used.... Hint: 🐇⚖ + 💩 + 🍼 in 🏞📅 & 🏢 🐇<(😊) vs 🐇<(😨) 🐕

• Sheriff et al. (2009) For both natural observation & experimental method caught snowshoe hares which were weighed to determine pregnancy, then measured faecal cortisol metabolite (FCM) from faeces of snowshoe hare females to look at impact of stress on reproduction • Also recorded the litter sizes produced by snowshoe hare females (for both natural observation method & experimental method) • Experiment method involved 26 pregnant hares (12 controls & 14 stressed), & used short randomised (prevent habituation) exposures of a trained dog to simulate a mammalian predator in stress pens

SA6: Describe the aspects involved with remembering a search image....

• Short-term, learnt, perceptual filter • What you're looking for affects detection, based on what learnt & expected -> not neatly separated • So top-down as well as bottom-up processes

SA3: Identify and describe the research on prey success ar avoiding predators, including the methods used and the findings....

• Sih, (1984) used lab based system to look at Mosquito larvae prey avoidance to different densities of Backswimmer predators in absence or presence of refuges • Know prey avoid predator more successfully when predator has lower mobility • Found prey & predator movement negatively correlated i.e. prey respond to predator cues by reducing movement • Found when refuge present the prey win (as -ve correlation) • Without refuge -ve & +ve correlation cancel each other out as prey avoid predators at equal strength to predators moving towards prey

SA3: Identify and describe the research on the predator avoidance by prey in relation to the resources present, including the methods used and the findings....

• Sih., (2005) observed preferences of tadpole(s) prey & salamander predator in arena split 50:50 into low & high resource patches (for prey) when either no salamander predator, caged predator, or free predator • Found high resource patch favoured by prey when free swimming predator & when no predator present • But also found prey avoided high resource patch when there was a caged predator there (shift preference), so trade off high resource with present of predator • Found no preference in predator for prey's resources when on own or when prey present as spend time equally between patches • Found - ve correlation on high resource side as prey are winning

SA2: Identify and describe the research on scaling laws of marine predator search behaviour, including the methods used and the findings... Hint: = 📉 🐟 = 📉 🐢 = 📉 = 📉

• Sims et al., (2008) investigated if search patterns matched distributions of ephemeral prey by recording vertical movements (diving) of multiple marine predator species using electronic tags, against time (seconds over months) • Found fluctuations in movement/step lengths with a skewed distribution that indicated Lévy (as near μ) • Lévy search found in most species studied e.g. basking shark & tuna - did for other species & found many predators eg turtles used levy • Levy search not found in catshark & elephant seal • Also found Lévy (highly skewed) distribution / movement in prey (e.g. Zooplankton & Krill)

SA2: Describe the research by Bartumeus et al., (2002), including the methods used, and the findings in terms of the size of the predator and prey...

• Simulation study comparing Brownian motion versus Lévy search in encounter rate of predator • One dimensional simulation, but both searcher (predator) & target (prey) move with random walks • Example of a simple model of predator-prey encounter rates • Looked at graphs as above line Lévy outperforms Brownian, below line Brownian outperforms Lévy • Found Levy out performs when prey 10 x smaller (e.g. mouse & owl) • Levy out performs when prey & predator same size (e.g. stoat & rabbit) • Brownian out performs when prey x 10 larger (e.g. millipede & ant) • When searcher larger (r) than target, Lévy outperforms Brownian • Predator tend to be bigger than prey so Levy search beneficial in most cases of the model

SA14: Identify and describe the research on the possibility that thanatosis is used by prey to decieve predators into thinking they are dead, including the main elements of research methods used... Also describe the findings and what these findings demonstrate... Hint: 𝟭. 🐥 + >-∧-∧- <(☠️) → 🐥 + >-∧-∧- <(✓🕶☠️) → ⬇︎💥 𝟮. 🐥 + >-∧-∧- <(☠️) → 🐥 + >-∧-∧- <(✗🕶☠️) → ↑💥 𝟯. 🐥 + >-♍️-- <(☠️) → 🐥 + >-∧-∧- <(✓🕶☠️) → ↓💥 𝟰. 🐥 + >-♍️-- <(☠️) → 🐥 + >-∧-∧- <(✗🕶☠️) → ↑💥 𝟱. 🐥 → 🐥 + >-∧-∧- <(✓🕶☠️) → ↑💥 𝟲. 🐥 → 🐥 + >-∧-∧- <(✗🕶☠️) → ↑ 💥

• Skelhorn et al. (2018) Used naïve domestic chicks as predators that were divided into three groups (each containing 30 individuals) & Indian stick insects as prey • Birds in all groups experience manipulation trials, in which they were placed in the experimental arena individually: group 1 encountered an unmanipulated dead stick insect; group 2 encountered a manipulated dead stick insect bound in purple cotton thread; & group 3 experienced empty arena • All groups then received a single test trial in which they encountered a live stick insect & due to roughly half of the stick insects displayed thanatosis when attacked - there were six distinct experimental groups • Found in experience-manipulation trials, they quickly learned to stop attacking unmanipulated & manipulated dead prey as they found it unpalatable • Found insects that displayed thanatosis post-attack in main experiments were rejected significantly more often by birds that had experienced unmanipulated dead stick insects than by birds that had experienced manipulated dead insects or an empty arena • Thus found thanatosis was only an effective defensive strategy when predators had learned that dead prey where unpalatable, which demonstrates that in stick insects thanatosis causes predators to misclassify live prey as the unpalatable dead prey they resemble • Also demonstrates that thanatosis exploits predators' learned aversions to dead prey

SA6: Identify and describe the first research that investigated if there was evidence for the use of masquerade, including the various methods used and the findings...

• Skelhorn et al., (2010) used stick-mimicking brimstone moth caterpillars, early thorn moth caterpillars, or hawthorn twigs • Manipulate early encounters of chicks as groups pre-exposed to either: - Empty arena (nothing) - Arena with hawthorn branches - Arena with purple-cotton-bound hawthorn branches (chick knows purple = inedible) • Then in main experiment measured latency of attack by chicks given either 1 Brimstone caterpillar, 1 Early thorn catterpillar or 1 twig • Found chicks with no experience of twigs or experience only of purple twigs attacked the catterpillars faster than chicks with prior experience of twigs, which handled them more cautiously • Shows that masquerade only works if chicks have learnt that twigs aren't edible - i.e. it's not failed detection

SA11: Identify and describe the research on how activity drives predation-growth trade-off in tadpoles, including the two different experimental methods used and the findings...

• Skelly (1992): used field experiments & lab experiments to assess nonlethal impact of predator presence on Hyla tadpoles • In field used 12 pens in pond containing tadpoles (weighed before put in pens), with six predator treatment pens also containing a single tiger salamander (Ambystoma) larvae predator in the screen cylinder. • Counted the number of potential predators in the pens collected after 14 days & weighed the tadpoles • Laboratory experiment looked at activity of different sized tadpoles that were in predator treatment containers with tiger salamander (Ambystoma) larvae predator in the cylindrical cage (compared to activity of those in non-predator treatments). • Found for field experiment that tadpoles growing in the absence of predator were 54% heavier than those growing in the presence of the predator, while development of tadpoles was also more rapid in the absence of the predator • For lab experiments found both sizes of tadpoles had reduced activity in response to the predator presence in the laboratory. • So found tiger salamander larvae predator resulted in prey reduced growth

SA11: Identify and describe the research on the affect of reduced prey activity in tadpoles, including the different methods used and the findings...

• Skelly (1994): Examined activity of tadpole prey when given tricaine (an anaesthetic) or control solution in presence of Anax dragonfly larvae predator in cage (replicated 4 times in 8 container). • Then observed activity of tadpole prey when given tricaine or control solution in presence of Anax predators in same containers, so the predators could attack the tadpoles (replicated 6 times for a total of 12 containers). • Found that tadpoles given tricaine had significantly reduced predation by dragonfly larvae compared to control tadpoles that were 4 times more likely to be consumed • So less activity significantly reduced predation by dragonfly larvae

SA11: Identify and describe the research on response depending on different prey size, including the methods used and the findings...*

• Skelly, (1992.) • smaller prey can respond to their greater vulnerability • Smaller tadpoles respond more strongly to predator presence • tiger salamander larvae predator • no pred → some prob survival • Small pred → large prey more likely to survive • Large pred → small prey more likely to survive • Small prey respond more strongly to pred presence → reduce activity more

SA3: Describe the different spatial scales in order to demonstrate why the spatial scale matters...

• Small scale 1 km, within sensory range so prey close • Small-medium scale ~1 to 10km, some information e.g. odour at • Medium scale ~10 to 100s km, search without info • Large scale at > 100s km, some info (e.g no ice) from environment • So at the largest scale, it can be habitat cues (i.e. prey are found in certain habitat types) not just cues coming from actual prey individuals.

SE11: Identify and describe the research on cannibalistic predation in relation to being bigger reduces risk, including the methods used and the findings...

• Sogard & Olla., (1994) Looked at cannibalistic predation by putting together pairs of different sized pollock fish in tanks & recording number of fish that completely disappeared due to being swallowed whole • Found pairing small & large fish → high probability of consumption & death → if small fish large more likely to survive → can still eat big fish though based on mouth width • Large mouth width of one fish & small body depth of other fish → strong probability of consumption • Thus, outcome depended on ratio between the mouth width of the larger fish & the body depth of the smaller fish • "Cannibalistic individuals could consume fish close to the maximum size physically possible under gape limitation; at this size the length of the cannibal was approximately 1.7 times the length of the prey."

SA13: Identify and describe the research on functional response curves of predators in terms of the reduced risk via predator conflict as well as the enhanced risk via predator facilitation, including the methods used and the different findings.... Hint: 🐟 + }⊂⊃≺ ➡︎ ↓⚠️⧽⁌=< vs 🐟 + }⊂⊃≺ ➡︎ ↑⚠️ ⧽⁌⁍⁍<

• Soluk., (1993): carried out series of microcosm tank experiments to determine the functional response curves for two common types of stream predators, sculpins & stonefly larvae, on two behaviourally & morphologically distinct types of mayfly prey (B. tricaudatus & E. subvaria) • Found effect of combined predators less than expected as deviation increased as prey density of B. tricaudatus increased. • Argued due to anti-predator response of the stonefly to the sculpin (a potential predator) by remaining hidden under stones, as well as response of the mayfly larvae (B. tric) which swim away from stonefly → thus predator conflict means less risk to prey as stonefly consume less • Found effect of combined predators more than expected, especially at intermediate prey density of E. subvaria • Argued due to the different behavioural response of the mayfly larvae to each predators, as prey respond to stonefly by doing scorpion posturing which makes them more conspicuous to sculpin fish predators, while sculpins chase prey into refuges where stonefly larvae are so can attack prey → thus predator facilitation means more risk to prey

SA8: Describe the use of eyespots as potential startle displays...

• Some Lepidopteran (butterflies) 'startle patterns' are eye-like • Mimic predator eyes (possibly) • Some spots always on display permanently • But many eyespots are permanently on display

SA11: Describe the Trade-offs within the predation context...

• Some adaptations can also be costly in the same context they are adapted for. • Often benefit at one stage of predation offset by cost at another eg warning colours •.But the adaptation will be selected if benefit > cost • May prevent predation now, but not in future

SA3: Describe why the aggregation of prey matters by using the research by Travis & Palmer (2005) to illustrate this...

• Spatially explicit model of predator moving in a grid • Also varied aggregation in prey • Response to prey density reduced when prey are aggregated i.e. get decrease in the encounter rate • Response to prey density stronger when prey not aggregated • Big effect on encounter rate

SA5: Identify and describe the research on disruptive coloration as a possible mechanism that exploits edge detectors in early visual processing, including the methods used and the findings...

• Stevens & Cuthill (2006) took photos of targets on trees & calibrated these for bird colour vision • Used edge detector algorithm from computer vision • Found triangles detected by algorithm less often in disruptive treatment as patterns intersect edge it interfere with detection of true edge

SA5: Identify and describe the research on maximum disruptive contrast patterns, including the methods used, the findings, and what this indicates about Cott's ideas...

• Stevens et al. (2006) used moths with edge-disrupting, & non-disrupting, patterns • Black patches matched dark grooves in oak bark, while the other patches did, or did not, match the bark ridge • Found edge-disrupting background-matching did best • Found edge-disrupting background non-matching as good as non-disruptive background-matching • Cott was right about differential blending (at least one colour must match a background colour) • But Cott (for once) was wrong about one thing: maximum contrast isn't good if it leads to poor background matching

SA8: Identify and describe the research on if eyespots intimidate predators because the shape and colour are like eyes, including the different methods used and the findings...

• Stevens et al. (2009) Randomized block design experiments, targets were composed of a gray paper "wing" with a black center & either a white (exp 1) or different coloured (exp 2) surround • These had variations in marking shape (circle or bar) & arrangement (eye-like vs non eye-like), & the targets were pinned to trees with meal worms, if meal worms not eaten = birds scared. • For exp 1 found no difference between arrangements & shapes as they all equally scared the birds • For exp 2 found no advantage of shape or yellow & black colours (mimicking predator eyes) compared to conspicuous colours for non eye-like targets • Indicates eyespots act as a conspicuous signal to predators - eyes alone don't scare them

SA5: Identify and describe the research on camouflage through distraction marks, including the methods used and the findings...

• Stevens et al., (2012) had people search for targets (moths) on computer with 3 different moths; control, centre mark, or offset mark • Found control treatment was best so distraction marks don't work as they attract predator attention

SA1: Describe the bias in behavioural literature toward prey behaviour...

• Studying anti-predator behaviour in prey is far more common than studying predatory behaviour of predators • "predators have been treated as abstract sources of risk to which prey respond" • Often because a) easier to assume fixed risk of predation b) prey easier to observe

SA9: Describe suction feeding as one of the most common feeding modes in fish as an example of locomotion in terms of feeding morphology coevolution, including the trade-offs associated with this example...

• Suction feeding involves the rapid opening of the fish's mouth cavity to create influx of water • Trade off between speed of approach (aka 'ram' speed) & suction performance (faster = poorer suction) & reduced accuracy of timing & prey's relative position, so evolved larger mouth to compensate. • Faster ram speed favoured with evasive prey

SA5: Describe the other reasons to be countershaded as suggested in the review by Ruxton et al., (2004), including other research on how the weather affects optimal countershading...

• Suggested that it provides protection from UV based on more melanin pigmentation being on the upper side of animals & save cost of pigmentation where it's not needed (i.e. not needed on animal under-side as not exposed) • Also animal may be viewed from different angles & against different backgrounds e.g. from below vs above • Penacchio et al., (2015) used complex modeling of light fields by illuminating objects • Found optimal countershading depends on the illumination as found direct sun causes sharp shadows so optimum would be strong (edge) countershading, but in clouds/shade there are diffuse shadows so weak countershading would be the optimum

SA2: Describe the some of the other findings by Humphries et al., (2010) based on the data if one blue shark....

• Switched between Lévy or Brownian depended on productivity of areas e.g if prey abundant then no point in doing large movement (Lévy) • In low productivity areas e.g. deep off shelf there was Lévy-like distribution • In high productivity areas e.g. shelf there was Brownian-like distribution • 21% of sections still fitted Brownian motion

SA11: Describe the Risk-allocation hypothesis / model by Lima and Bednekoff (1999)....

• Temporal variability in predation matters •Anti-predator behaviour greatest when risk high but infrequent • If often exposed to predation, should show reduced anti-predator responses to allow time for non-anti-predator behaviours (feeding, mating, etc) • I.e. anti-pred highest when risk high but infrequent, if constantly see predator then less vigilant to predator • Counter intuitive, but a direct outcome of conflicting pressures (trade-offs)

SA13: Describe trophic cascades including some various examples to illustrate this....

• The mechanism behind mesopredator release and control of herbivore population sizes, but very general • Occurs when a trophic level is suppressed (e.g. sea urchin) • E.g.s: great sharks & scallops, dingoes & marsupials, sea otters & kelp, wolves & aspen → all occur via reduced prey density • E.g. Negative correlation between more cougar & less deer, but positive correlation between deer density & human density

SA6: Explain/describe how the unprofitable model is behind the evolution of both Masquerade and Batesian mimicry, including some examples...

• The model in Batesian mimicry is unprofitable; so is a stick, a leaf, a stone, bird poo. • So masquerade & Batesian mimicry both evolve through the benefits of not eating unprofitable prey • Masquerade = ignore; Batesian mimicry = avoid • That's a difference, but can't always tell so if something's dangerous, best to avoid it • Evolutionary dynamics will differ • An aposematic model suffers a cost from being mimicked; a dead leaf or bird poo does not (although a twig might, a bit) • Batesian model - suffers cost from presence of mimic, model suffers cost • No cost for mimic as won't eat "stone" etc.

SA2: Briefly describe the encounter of a predator based on the model by Travis and Palmer (2005)... Hint: ______(_🐐_____🐅_________)_____

• The predator searches a circle of radius p centred on its own position • Can locate prey items within the circle with 100% efficiency

SA10: Describe how the research findings of Herbert-Read et al., (2015) in relation to does this behaviour benefit the 'selfish' individuals?

• The selfish herd states that individuals should adjust their position within groups owing to differential predation risk • Using densities found in real fish schools they looked to see whether the individual nearest the stimulus 1 sec after it was informed or uninformed • As informed individuals increase their speed, they penetrate the group and mix with uninformed individual, diluting their risk of capture • i.e. the risk to the members on the edge of the group is roughly equal to those in the group

SA7: Describe the use of Aposematism as a form of defence, including how it works so predators avoid prey...

• The term was coined by Poulton (1890) & is used by animals to signal unprofitability • Works by: if the predator eats prey then the predator feels ill, so associates colour pattern of prey with feeling ill (Pavlovian conditioning), so the predator avoids all similar prey phenotypes • Although innate avoidance possible as evolution has 'learnt' the correlation between coloration & defence e.g. 'snake detector' neurons in macaque brains (Le et al., 2013)

SA6: Identify and describe the model that suggests how can this "adaptive valley" from camouflage to mimicry could be crossed...

• The two-step model" (Nicholson 1927) -mutation of major effect first, that makes it pretty like the model, then fine-tuning by further mutations of mimicry of small effect • Genes controlling each component must be tightly linked (a 'supergene') so can't be separated by crossing over • The initial imperfect mimic could only evolve in an area where the model is very bad (dangerous) & very common

SA9: Identify and describe the research on the oddity effect in terms of size, including the methods used and the findings...

• Theodorakis (1989): varied body size of fish in shoals (by using three different species of minnow prey) in pools, released Bass predator & counted number of fish remaining after 24hrs • Swapped which prey type was minority to avoid effect being due to bias for actual prey type • Found significant variation away from random targeting e.g. attack small fish species more when rare • Significant preference for a body size of prey when majority:minority, not when balanced 50:50

SA3: Identify and describe the research on local enhancement (a type of social information) being used by predators, including the methods used and the findings....

• Thiebalt et al., (2014) Used video cameras with GPS loggers on 36 Cape gannets to look at behaviour when foraging • Found bird change direction to patch where other birds present (indicate food present) • New birds fly directly toward the others to give the reaction distance, looked at reaction distance & found it correlates with no. gannets aggregated • Group size of flocks in air, not birds rafting on the water surface, affect reaction distance • Also found number & frequency of dives increased with the number of other gannets aggregated

SA12: Describe why "the classic view of a symmetric hare-lynx interaction is too simplistic" including identifying and describing the research this quote came from, as well as the methods used and the findings... Hint: 🌿→🐇←🐱🐺🐻 vs 🐇→ 🐱

• This predator-prey population dynamics was originally thought to be top-down for hares & bottom-up for lynx • Stenseth et al 1997: carried out a meta-analysis on time series data for snowshoe hare & lynx, to estimate the number of key interactions determining the dynamics of these species • Found the snowshoe hare appear to be regulated from below by its food sources (bottom-up) & from above by a variety of predators including the lynx (top-down) • Found lynx seems to be regulated only from below & primarily by the hare (bottom-up) • So easy bottom up control in the lynx as the hare is its major food source, but hares story is more complicated, so the hare is driving the cycles.

SA4: Describe why the work by Thayer (1909) was important for understanding camouflage...

• To understand an animal's colours, you need to view it in its natural environment • The animal's colours are a sample of those in its background • But sometimes Thayer took it too far e.g. Peacock & Flamingo, flamingo to match setting sun.

SA7: Describe the use of toxicity by prey and the benefits of this, including how toxicity can evolve...

• Toxin for hunting originally evolved in prey to keep predators away • If via touch then advantage to self (e.g. dart frog); can eat poisoned food as can take up the poison (sequester) & store it • Can evolve as a by-product of its use in hunting or dealing with toxins in food (&/or through kin selection)

SA10: Describe the research by Friedlaender et al., (2017) on whether directionality of rolls (to right or left) are lateralized at the population/ individual level (in relation to the conventional lateralisation paradigm), including the methods used and the findings...

• Tri-axial accelerometer attached to blue whales to record their direction and size of rolls during lunge feeding events, to investigate whether blue whales evolved strategies that might improve foraging success. • 63 whales tagged, & 2863 total feeding lunges recorded • Calculated a laterality index (LI) for each individual that made 10 or more rolls (n = 49 individuals) to assess whether rolls were lateralized at population & individual levels. The LI of each individual was calculated based on the numbers of rolls that an individual made to the right & left, respectively. • Found at population level the lateral distribution differed significantly from expected when assuming no individual-level lateralization. • Individuals that were left lateralized were more likely to perform larger rolls and feed at shallower depths • Individuals that were right lateralized were more likely to perform smaller rolls and feed at greater depths • Also found there were significantly more right-lateralized individuals than left-lateralized individuals. • Thus found context-dependant laterality

SA12: Identify and describe the the research on the whether the impact on energy transfer is caused by higher prey density or the presence of predators, including the research methods used and the findings....

• Trussell et al. (2006): Created two treatments, each having two levels, that were randomly assigned to feeding patches of barnacles (mesocosms), with each treatment combination being replicated 10 times. • The treatments had varied predator risk cues (crab, or no crab) & varied snail prey density (high = 9, low = 3). • Measured tissue production (i.e., growth) for 3 randomly selected individuals in high density treatment that were then marked & all 3 snails in low density treatment were marked & measured. • Recorded the total number of barnacles consumed by snails every 7-10 days by taking digital images of the top & bottom of each tile. • Found that predation risk caused a significant reduction in snail energy intake relative to the control e.g. predation risk suppressed tissue production by 83% at low conspecific density & 60% at high conspecific density. • Found the effects of predation risk were much stronger & explained twice (32%) the variation in growth efficiency compared to conspecific density (15%). • Indicates that energy transfer relative to food consumed by whelk slowed due to fear of predation from crab

SA7: Identify and describe the research investigating the relationship between gregariousness (aka being in groups) and toxicity, including the methods used, the findings, and what could be indicated...

• Tullberg & Hunter (1996) compared 800 larvae of butterfly & separate similarity via phylogeny from similarity via adaptation (i.e. the 3 characters coloration, defence & lifestyle) • Two seperate analyses, with lifestyle as dependent character, & analysis coloration being the independent in one, while defence being independent in the other • If only one evolutionary change then not strong association as based on one common ancestor, but if multiple evolutionary change then stronger evidence of association • phylogeny is not causal (just a degrees of freedom problem) independent evidence • Found positive association for unplalatablenes (i.e. repellent defence) & gregariouness • Could indicate that gregariousness follows unpalatability (i.e. anti-Fisher) but not true as can't identify which preceded which, due to the relative rarity of gregarious species (Ruxton & Sherratt., 2006)

SA12: Identify and describe the research on the effect of lake habitats, including the methods used and the findings...* (check)

• Turesson & Brönmark 2007: simple study of turbidity, prey density & encounter rate - lab & field research • Filmed 15 lakes with varying turbidity • Encounter rate determined by visibility (camera detection distance) not prey (fish) density • Showed camera detection correlates with encounter rate → not density of fish • But prey density & turbidity positively correlated → more complex than expected

SA12: Describe the three main types of functional responses in relation to the relationship between predator consumption rates and prey density, including some examples to illustrate these if possible...... Hint: 1. ↗︎⃤ 2. ⦧⃤ 3. ∫⃤

• Type I: linear response, 'null' expectation, used in Lotka-Volterra predator-prey model, but rare • E.g. directly proportional - filter feeder double rate of krill taken in • Type II: saturating response, Predator's 'handling time' is significant. • can be exploited by prey -> predator swamping e.g. turtles hatching (high emergence rate) •Type III: sigmoidal response, initially slow response to increased prey density, possibly due to learning • e.g. search images

SA12: Describe the main aspects of type II and type III functional responses in more detail, including what they can be used for...

• Type II patterns can be represented by Holling's 'disc equation' • Cannot predict prey consumption by predator based on prey density without knowing the curve • Predator handling time is the time from detecting prey to completely processing the prey & being able to hunt again - so includes time to capture prey, consume prey & digest prey. • Type III involves stabilising: low density prey disproportionately unconsumed • Cannot predict prey consumption based on prey density without knowing the curve • Involves learning what prey look like (recognition), & how to successfully capture prey. • Can happen with prey switching - temporary specialisation in the most common prey type • Thus frequency dependency

SA8: Identify and describe the research on the startle displays of katydids, including the methods used and the findings....

• Umbers & Mappes (2014) recorded behaviour of katydids in arenas before & after treatments, used 3 nontactile treatments ('bird fly over'; 'tap near head'; & 'blow on') & 2 tactile treatments ('poke' - simulate bird peck; 'pinch & lift' - simulate bird attack), with observation as control treatment • Found majority performed defensive display of flashes warning colours in the poke (95%) & pinch & lift (95%) treatments but most showed no defensive reaction to other treatment e.g. the fly over etc. • Indicates defence is used so that predator is 'surprised', so abandons attack, or pauses long enough, or is distracted enough, that prey can escape. • Not convinced as katydid is toxic -> not necessarily best so only reveal colour when attacking

SA6: Describe the research by França et al., (2017) on the benefits of mimicry, including the methods used and the findings... Hint: ⊂☐∎⫾∎⫾∎☐∎⫾∎⫾∎☐⦂⊃ ⊂☐∎⫾∎☐☐∎⫾∎☐☐⦂⊃ ⊂☐«»☐«»☐«»☐☐⦂⊃ ⊂☐∎☐∎☐∎☐∎☐∎⦂⊃ ⊂☐☐☐☐☐☐☐∎⫾∎⦂⊃ ⊂∎∎∎∎∎∎∎∎∎∎∎∎∎⦂⊃

• Use snake replicas with 6 different colour patterns patterns such as tricolor triad (coral snake & mimics), tricolor dyad, black diamond blotches outlined in yellow on red (imperfect mimic), uniformly gray (control) etc. • Randomly distributed 600 replicas in quadrats in the national park & looked at number of dents (e.g. pecks) to determine the number of attacks by predators • Found 74% of attacks were inflicted by birds & 26% were attacks by carnivorous mammals. • Found gray control replicas had the highest number of attacks to body & head (66 attacks), while tricolor triad had the lowest number of attacks to body & head (14) - Shows mimicry works well

SA10: Describe the rest of the research by Herbert-Read et al., (2015) on if 'faster moving individuals are allowing information to be propagated through the group', including the methods used and the findings...

• Used a model to test whether speed changes & local interactions facilitate the escape wave • Used 10% 'informed' individuals (nearest the to group front & moved more rapidly away from stimulus) & 90% 'uninformed' individuals (moved more slowly towards stimulus) for various group sizes/densities of fish • Found when density was too low there was no information transfer, while when density was too high there was also no information transfer - as the group takes the direction of the uninformed majority • However found at intermediate densities there was information transfer as escape wave of turning created in the entire group (see plot) • Also found the increased speed by informed individuals was essential for the group changing direction - low cognitive demands • Found the probability that an informed individual was nearest the threat varied with group density, with uninformed individuals at greatest risk in densely packed groups & informed individuals at most risk in sparse groups. • Also found for shoals of 50 or more fish the observed group width was close to the value that maximized the probability of the group switching direction (for both model & real fish)

SA5: Describe the unpublished research by Cuthill et al., including the methods used and the findings...

• Used artificial moths & birds search with moths having enhanced edges (stepfunction) or smoothed edges; tracked survival • Found enhanced edges survived best; repeated with humans who missed enhanced edges most often • So harder to spot

SA8: Describe the use of dazzle camouflage in nature, including identifying and describing the two pieces of research that demonstrates this...

• Used by Zebras but not for stopping lions, but to stop biting flies instead • Caro et al. (2014): carried out phylogenetic analysis & analysed coat patterns & colours using images of extant and extinct equid subspecies • Found the best predictor of zebra 'stripiness' is the distribution of biting flies • How & Zanker (2014): used side-view photographs of zebra & domestic horse, & simulated scene viewed by a flying insect during its final approach as it comes in to land • Found vertical stripes on flank region produce motion signals similar to wagon-wheel so response in fly eyes to stripe signals maybe causes confusion

SA7: Describe the other research by Barnett et al. (2016) on caterpillar distance-dependent aposematism, including the methods used and the findings...

• Used dough caterpillar-like baits which were either: plain yellow; yellow with thin black stripes; yellow with thick black stripes; plain black; black with thin yellow stripes; olive green etc. • Tested if reduced levels of aposematic conspicuousness had survival benefits when predated by wild birds in natural conditions • Found the most conspicuous patterns (plain yellow or thick stripes) didn't survive the best, while yellow with thin black stripes did best

SA3: Describe the use of odour (olfactory) cues, including the downsides to this and describe some research that demonstrates this...

• Used for communication (e.g. defend territory or attract mates) but predation is an assumed to be a cost as they can 'eavesdrop' on signals • Hughes et al., (2010) manipulated male mouse odour scent cues, looked at how different patches attracted different predators • Within 2 days found more than 50% of scented locations were visited by cats, foxes & snakes, while only one control plot was visited by a fox

SA5: Describe the research by Allen et al. (2012) on another possible function of countershading, including the various methods used, the findings and what this supports...

• Used life-size deer model to predict optimal countershading, while images of 114 species of ruminant were compared to the countershading model • Created a phylogenetic tree based on a ruminant species to look at variations in counter shading in order to find the best predictors of coats' countershading characteristics • Found countershading was stronger & step edges more common in species with higher lighting scores • Found that species closer to the equator gen- erally had stronger countershading, which supports the self-shadow concealment hypothesis (create uniform appearence by hiding shadow on under side)

SA2: Describe the research by Humphries et al., (2010) including the methods used and the findings...

• Used statistical method advocated by Edwards et al. 2007 to test between Lévy & Brownian movement • Collected more data using tags on marine predators so that it was largest data set assembled (>12M recordings) • Lévy search found in 14 species of open-ocean predatory fish, 47% of sections of trajectories

SA12: Describe the lynx and snowshoe hare as a classic example of predator-prey population dynamics, including the equation used to test this...

• Used to test Lotka-Volterra (& other population equations). • When hare abundance goes up, lynx abundance goes up, but then hare abundance declines, leading to a decline in lynx abundance etc. • Other factors affect hare abundance when lynx not present. • Snowshoe hares experience changes in population density in cycles spanning periods of about 8 to 11 years.

SA13: Identify and describe the research on the impacts of Intraguild predation within the multi-predator communities in Africa, including the various methods used, the research findings and what this research indicates.... Hint: ☀️ 🌧 ☞⧻ ◎ 🐆🐕 + ♘🐃♘🐗

• Vanak et al., (2013): almost all adults of focal carnivore species (e.g lions, leopards, cheetahs & wild-dogs) were fitted with VHF transmitters within the reserve & the number of individuals present & radio-tagged in the reserve varied over the years. • Focused on top 5 prey species (75% contribution to diet) e.g. impala, wildebeest, waterbuck, zebra, kudu, warthog, & giraffe • Generated a map of prey vulnerability for each of the carnivore species for the areas of the reserve • Examined effect of intraguild competitors for each of the carnivore species at multiple spatial scales during both wet season & dry season • Found Leopards & cheetah overlapped with home range of lions but minimized their risk using fine-scaled avoidance behaviors & restricted resource acquisition tactics • Found high cost of intraguild competition for cheetahs, (especially in wet season) as areas with rewarding large prey (e.g. wildebeest) were avoided when they overlapped highly with the activity areas of lions. • Found intraguild competition forced wild dogs into areas with lowest resource availability year round, as they used multiple tactics to avoid encounters with all predator competitors. • Indicates that differences in resource acquisition may be a consequence of avoiding intraguild competition

SA13: Identify and describe the research on the consequences for prey in relation to the different types of Intraguild predation, including the methods used.....

• Vance-Chalcraft et al., (2007): searched an electronic database (Web of Science) & citations within papers on the database for studies that included at least two predator species & a shared prey • Then compared the effects of intraguild predation using meta-analysis to examine general patterns across studies • Tested the predictions to determine whether prey suppression was weakened in multiple predator assemblages due to the possibility of unidirectional &/or mutual IGP

SA7: Describe the use of stotting by certain prey species...

• Vertical take-off on all four legs in e.g., Thomson's gazelle • Not 'running away' • Signals to predator that prey as seen them but also that prey is fit & can easily outrun them

SA3: Identify and describe the two pieces of research on the use of indirect visual cues by Kestrels, including the different methods used, the findings, and what can be suggested from these.... Hint:

• Viitala et al., (1995) looked at how they use urine on vole trails to locate areas to search by shining UV light & normal light on vole urine • Can explain how kestrels find new hunting areas after prey population crashes • Use UV to see urine as visit patch with UV indicates rich in prey as high urine • Indicates vision can also be used to detect cues that can reveal higher prey densities. • Zampiga et al., (2006) carried out similar studies using both adult & juvenile birds within 4 arena types: UV-filter + scent marked, UV blocking filter + scent marked, UV-filter + water, & UV blocking filter + water • Both adults & juvenile showed a preference for the arenas with UV-filters, but adults also scanned the UV-scented (more than water arenas) • Indicates the ability of detecting UV cues has a learned component (not innate)

SA5: Identify and describe the research on a certain dinosaur using counter shading, including the methods used and the findings...

• Vinther et al (2016) looke at conter shading in the dinosaur Psittacosaurus • Made life size reconstructions one in colour, & one grey (for calibrated photography) • Took photos of grey one in direct sun vs shade, & predicted colour pattern with optimal counter shading for different illumination conditions • Found the actual colour matches the forest shade prediction with diffuse lighting

SA1: Identify and describe the research 'testing' the theory by asking whether prey get closer to one another when under threat, including the methods used and the findings.... Hint: _______ 📹 + 🏃‍♂️ =》___

• Viscido & Wethey., (2002) recorded the movements of Fiddler crabs on beach being attacked by shorebirds & humans • Found predator stimulus causes group colony to get close together • Reduces Domain of danger (DOD) - the area or volume closer to that prey than any other. • Also found increases speed getting closer together.

SA2: Identify and describe the research that provides the first evidence supporting Levy flights in natural conditions, including the methods used and the findings....

• Viswanathan et al., (1996) attached electronic recording devices to the leggs of wandering albatrosses & then analysed the data collected • Found Lévy movement with big jumps & small movements, supporting Lévy flights in foraging animals • Also fits prediction of Lévy being used in big environments

SA13: Describe and explain how multiple predator species can interact to impact prey risk, including the different effects these predators can have on prey.... Hint: & 🐆 = ↓⚠️♘

• When multiple predator species interact there can be additive or emergent effects • Emergent effects are where effect is more than the sum of the component parts, & are often unpredictable (not independent, linear effects). • Emergent effects include: - Reduced risk: interference (negative interactions) between predators i.e. Reduced risk for prey if negative interactions between predators - Enhanced risk: different prey adaptations needed (trade-offs), positive interactions between predators (enhancement) i.e. Enhanced risk = prey need adaptions to cope with positive interactions between predators (enhancements) • Natural systems - more than one predator per prey, so complex food webs are the rule rather than the exception

SA2: Describe the problem of predators encountering prey (or prey trying to avoid predators)...

• When predators and prey have a small range in which they can detect one another - the encounter rates are important • Animals move around to increase or decrease likelihood of encounter • Often distinguishes Predator-Prey from other exploitative interactions

SA10: Describe the reasons why it is important to consider the relative risk that individual prey face depending on their location within groups as well as explaining why previous research on this has been flawed, and what is required to amend the flaws...

• When predators attack individual prey in groups - risk related to predator strategies used to isolate prey targets from within the group. • Previous empirical evidence shows that prey ths is isolated or on the edges of groups have greater risk of predation, but most studies have limited an individuals' relative risk in a single plane. • Also, most models investigating 'marginal predation', have only considered this from a 2D approach - okay for systems where prey form 2D group structures, but fails in systems where animals use both vertical & horizontal planes to move (3D) • For 3D systems need to investigate whether the predictions, & assumptions of the models, hold true.

SA11: Describe the model by Broom and Ruxton on when to flee in terms of trade offs...

• When predators search slowly, have a high prey detection rate, large advantage to head start, low energetic fleeing cost & high capture success → Run as soon as predator detected • Otherwise only flee once detected by the predator • Two extreme prey behaviours are optimal: run as soon as predator detected or flee only when detected by the predator, depends on likelihood of predator to detect prey etc.

SA2: Describe the rest of the results by Bartumeus et al., (2002) in terms of the movement by the prey and predator and the space available, including what thus indicates...

• When target (prey) is doing Lévy movement, Brownian can outperform Lévy • When searcher (predator) faster than target (V), Lévy outperforms Brownian • Thus target (prey) movement is VERY important in which search strategy is best. • Lévy outperforms Brownian as space (L) becomes larger (lower density)

SA11: Describe the use of habitat choice in terms of where should a prey animal spend it's time, also Identify and describe the research on this, including the methods used and the findings...

• Wild ungulates have positive correlation with grazing quality unless calving • Festa-Bianchet 1988: regularly searched the ranges & noted the time browsing, identity, location of the marked ewes, & also analysed feacal samples collected • Found pregnant ewes migrate from high-quality low-elevation winter range to higher elevation before plant growth has started there to avoid predation (although, can't feed as effectively). • Supported by non-pregnant adult ewes migrating later.

SA12: Identify and describe the research on translocation of consumed nutrients across aquatic habitat boundaries, including the methods used and the findings... Hint: 🚤⧻~~~~~⊿~~~~~~~~~~~~⊿~~~~~~~~~~~~~⊿~~~~~~~~~~~~ _____________⩤⦅⚆⦦•⃤⦆⟪____⩤⦅⚆⦦•⃤⦆⟪_____⩤⦅⚆⦦•⃤⦆⟪_____________

• Williams et al (2018): Grey reef sharks were tagged with acoustic transmitters that had been surgically inserted into their body cavities, for each individual tagged, recorded sex & size • Used receivers to detect acoustic transmitters (at range of ~250 - 300 m) to track shark movement & each time transmitters were detected, the shark identification number, date & time were recorded by the receiver. • Applied network theory to 4 years of acoustic telemetry data to allow the movement of sharks to be viewed as a system of connections, which offers insight into how species move between & thus connect habitats • Then calculated the potential quantity of nitrogen (N) that these predators may distribute i.e. waste deposited on atoll • From extrapolating from tagged sharks to population found deposition of 94.5 kg per day of nitrogen at the study atoll • Also found 86% derived from pelagic sources

SA9: Identify and describe the research on predator-prey coevolution (in Africa) in terms of chasing prey, including the methods used and the findings... Hint: +♘ 🐆+♘ 🍖🔬

• Wilson et al. 2018: hypothesized that predators should be more athletic than their prey, in order to overcome the prey advantages of deciding speed & using unpredictable manoeuvres • Looked at predator/prey pairs of Cheetah & Impala; & Lion & Zebra, as studied pursuits in open terrain & used behavioural-GPS colours • Took biopsy of muscle from hind leg (flare density & size), compared these between pairs • Determined speed & distance etc.,; found predators should be winning as predators had 20% higher muscle fibre power • Found Cheetah 50% faster, Lion 24% faster (faster acceleration as 2x as powerful as prey), 73% Cheetah & 70% Lion better at deceleration, while 100% Cheetah & 89% Lion more powerful during maximal acceleration • But found turning rate of prey much higher/faster than predators, so lower prey speed initially as can turn more, more unpredictable - was hard for prey to outrun predator so adopted manoeuvrability to survive • Less overlap at low prey speeds, because they are more manoeuvrable & can turn more (unpredictably) e.g. Cheetah turns a bit but impala turn more, while Zebra turns more than Lion • "high-speed manoeuvring pursuit in open terrain is a commonly used hunting technique" as part of the capture-evasion model

SA6: Identify and describe the research on the effect of background complexity to recognise prey, including the methods used, the findings and the conclusions that can be made from this...

• Xiao & Cuthill (2016) used identical fake moths (one colour) on varying bark complexity & used feature congestion matrix • Looked at sucess of avian predation (e.g. blue tit), finding a dead mealworm attached underneath the artificial 'moth wings' pinned on trees, as well as for human detecting the same targets on exactly the same trees • Found the targets survived better on more cluttered bark (especially orientation) • Also people had to be closer to detect targets on more 'cluttered' bark • Conclusions - although birds have very different colour vision from humans, the same things make visual search difficult for birds & humans • Can quantify background 'complexity' in ways that matter for birds & humans, based on known mechanisms in early visual processing

SA3: Identify and describe the research on dispersion of prey applying to 3D volumes, including the methods used and the findings, as well as how this may differ to other research looking at 2D...

• de Margerie et al., (2018) tracked movement of the common swift in 3D • Found increased path tortuousity (less straight) in area prey found in previously, very small decrease in speed • I.e. Found path less straight after detection prey, little difference in change of speed (possibly stay airborne instead) • Found changes in head direction with atypical flight posture & more convoluted flight when prey detected • Difference to other studies in 2D or on terrestrial & aquatic due to flight constraints (min. speed) as they slow down in profitable places unlike swifts

SA9: Describe some of the various morphological adaptations used by predators, including some examples, and what is often required to use these...

• extremely diverse, some weird & wonderful • Talons are common & big teeth • Long tongue & web etc., less common • Velvet worms squirt sticky glue to immobilise prey • Like animal colouration, not behavioural adaptations, but used in conjunction with behaviour (e.g. sticky tongue is useless unless know how to use it, like cryptic animals often keep still), & these morphological adaptations are often exploiting the prey's behaviour.

SA10: Describe the rest of the research by Herbert-Read, Romanczuk, et al., (2016) in order to understand why sailfish hunt in groups, including the methods used and the findings...

• used a simple mathematical model to allow investigation of the rates at which sailfish catch sardines in different predator group sizes • Sailfish come in & have a probability of catching, probability of catch is related to how injured the shoal is • How injured the shoal is is based on how many attacks there have been on the shoal, with hunting time being limited (certain number of hours) & can be changed in the model • The model showed: • If hunting time is unlimited, its beneficial to hunt alone as don't have to share prey with conspecifics • However, predators don't have unlimited time & want to maximise capture rate, so as hunting time becomes limited, it becomes beneficial to hunt in groups as more prey are injured • It also showed no advantage in a 'free riding' strategy

SA11: Identify and describe two pieces of research on the risk-allocation hypothesis, including the methods used and the findings...* *

•Mirza et al (2006) • Lower response to higher predation cue in fish frequently exposed • expose prey to diff pred risk levels • Rarely compared to commonly • Frequently exposed responded less • Rodriguez-Prieto et al., 2009. • FID of approaching human (habituated to at high pedestrian sites) or novel robot vehicle (not habituated to) • birds with varying pedestrian traffic • Risk allocation fits both stimuli, but especially the one they are habituated to

SA2: Identify and describe the research findings on the impact of sensory systems on the search strategy used...

▪Bank et al., (2015) compared horizontal, circular & vertical pupil shapes, including ancestor analysis & found: • Significant correlation between vertical pupils & animal being ambush predator (44 of 65 frontal-eyed ambush predators had vertical pupils) • Nocturnal animals were more likely to to have sub-circular & vertical pupils, while diurnal predators tend to have circular pupils • Animals with circular pupils were more likely to be active predators • Prey animals have horizontal pupils as this allows them to scan the horizon for predators & guides rapid escape

SA3: Identify what prey can do when no information and when there is some information...

▪No information about predators: • Reduce movement - reduce encounter rate • Use refuges e.g. hiding • Aggregate - reduce encounter rate ▪Some information about predators: • In response to cues from predators → move elsewhere, or respond as above ▪ All of these have costs