Animal Behavior

During plagues locusts have the potential to affect the livelihood of one in ten people on the planet

"Even after 50 years, fighting locusts is more of an art than a science" Why do insects exhibit large-scale collective motion? What biological processes underlie mass collective motion, mechanistically and functionally?

Masquerade

'Camouflage without crypsis' Involves resembling inedible objects Or pretend to be a different animal... From ant-mimic spiders to spider-mimic flies

How do ecological conditions influence social behaviour?

'comparative method'

Group movement relies on

'consensus building' regarding timing and direction

"If parental inclinations have been shaped by natural selection, there are at least three classes of circumstances in which we might anticipate some reluctance to invest in a newborn:

(1) Doubt that the offspring is the putative parent's own (2) Indications of poor offspring quality (3) All those extrinsic circumstances [...] that would have made a child unlikely to survive during human evolutionary history"

Generalized reciprocity

* All individuals contribute to some common good from which all group members subsequently benefit o Just the fact that they all live in a common place, they are protecting themselves

The selfish herd

* Animals predation risk proportional to the size of it's domain of danger

Worker policing

* Any worker behaviour that reduces reproduction by other workers * Might include aggressive behaviour or eating of eggs laid by females other than the queen evolved in honey bees

Simple Theory- difficult assumptions

* Center individual can have a larger domain of danger (DOD) and edge individual can have a smaller DOD * Predators attack prey of different o Body sizes o Sex o State of hunger o Experience o Appearance

Mutualism

* Cleaner fish remove parasite from inside of bigger fish mouths, but tempting to eat part of the client because more nutritious, but don't because want to have a good reputation and want others to be nice to them as well

Cost-Benefit Analysis

* Completion, disease * Better hunting

Group augmentation

* Fitness of all group members increases with the size of the group * Hunting dogs, larger pack, higher success o Increases competitive ability o Increased hunting success

Sentinels (sacrifices themselves to prey) in meerkats

* Give off alarm when see predator to protect from predators but because it is the first to see predator, it is most safe Best behavioural strategy once the animal is fully fed By-product mutualism

Reasons why social insects don't revert to solitary life?

* Hamilton's rule. Benefits of social life are large * Worker caste is irreversible - can't mate.

Hypotheses for altruism - Kin selection

* Individual's total (inclusive) fitness = personal fitness + r *(fitness of relatives) * Reproduction by identical twin = reproduction by self

Group augmentation explains phenomena such as

* Involvement of unrelated individuals in cooperative activities * Kidnapping of unrelated juveniles from neighboring groups * Killing of young born to neighboring groups - you decrease their size for competitive advantage

ED Wilson

* Kin selection does not explain evolution of sociality * What Wilson and others forget is Hamilton's rule has b and c, very important parameters

Kin Selection or Inclusive Fitness

* R b > c * Relatedness to individual benefits needs to be greater than the cost to self * Microsatellites to analyze relatedness Explains the many instances of cooperation amongst related individuals

George R. Price

* Re-derived Hamilton's rule * Introduced the concept of EES (with John Maynard-Smith)

Social vs Aggregation

* Social animals must respond to each other (societies) * Aggregations form due to individual begin drawn independently to a common resource * Natural selection is not a respecter of sociality itself * Animals will only form groups if they gain individual advantage (selfish)

Selection for group living

* Vigilance * The many eyes effect * The confusion effect o Zebras have black or white stripes? * Mobbing o Birds much larger then themselves fly in front * Pursuit-deterrence * Dilution effect

... or Malcot's method

* What is the probability of an allele being inherited from father? F * What is the probability of an allele being inherited from mother? M * What is the average probability? r=M+F/2

Multiple mating: a complication

* Workers may benefit by not acting in the best interests of the colony * If the number of matings exceeds 2, workers benefit from reproducing themselves • Any worker behaviour that reduces reproduction by other workers • Might include aggressive behaviour or egg eating

Evolution of altruism is impossible to explain in terms of personal Darwinian fitness

* Wynne-Edwards: altruistic behaviour evolves for 'the good of the species'

Feedback between individuals

+ve or -ve

Visual displays vary according to distance

- Fiddler crabs display more intensively and frequently to distant crabs

Advantages of group living

- Groups offer protection against predators - Animals can often forage more effectively in groups than on their own

Grasshopper infected with parasitic fungus exhibit a 'behavioural fever'

- Increase activity and increase basking

Bumblebees parasitised by conopid flies

- Larvae hatch inside bee and begin to consume it

Host birds may reject batch of eggs if:

- See cuckoo in vicinity of nest - Detect cuckoo eggs in their nest - Detect cuckoo chicks in their nest Close scrutiny has led to cuckoo strategies and a signalling arms race

Reduce encounter rate with predator

- Simple clumping of prey distribution - Selfish herd

and displays vary according to background, especially in terms of contrast between signals and background

- Squirrels in dense woodland flick their tails more dramatically - Male sticklebacks in turbid Baltic waters have to court much more vigorously - Warblers in low light environment have brighter plumage

Reduce success of predator

- Vigilance - Dilution of risk - Confusion - Predator-predator interference - Mobbing, cooperative defense

Crickets, Gammarus, nematomorphs, acanthocephalans

- different expression of proteins Up-regulates CRAL_TRIO, only when mature Uninfected photophobic; infected attracted! Similar effects in Gammarus infected with acanthocephalan Using proteomics gives us insight to behavioural switches This has potential applications Knowing how the brain regulates behaviour is key goal in 'pure' research

Generally encysts and appears 'inert' but...

- sex specific effects -slower reaction times - links to schizophrenia including hallucinations -reckless behaviour -a increase in number of traffic accidents

Average payoff to aggressors

-10a (likelihood they will meet another aggressor) + 40 (1-a) (likelihood they will meet submissive)

Lots of different mechanisms proposed:

-Cryptochrome receptors activate electrons in eye - can animals see the electric field? Evidence esp from birds (couldn't perform w/o light) -Magnetite - magnetic iron oxide produces a signal. Pigeons have this in their beak Could be either, or both. We don't know as yet. Studies in trout established connectivity between magnetite-based receptors & brain. Most mammals, including humans have magnetite, esp in head & nose but connectivity with brain unknown

Examples of signals exploiting receiver bias Courtship in water mite Neumania papillator

-Male vibrate first and second pairs of legs -Signal similar to struggling copepods -Female strongly attracted to stimulus

HP guppies

-Mature earlier -Mature smaller -Produce more and smaller offspring.

Presence of chemical cues can allow direct identification of predator

-Predator kairomones -Disturbance cues -Alarm cues

Other main advantages to group living:

-Reproductive success -Energy/resource conservation

With more individuals, groups can search an area more effectively

-When one individual finds food, other individuals respond to social cues and arrive at food patch ('local enhancement') - The group acts as a 'supersensor' - the sensory capabilities of each individual in a group are, to an extent, summed. Group shape may facilitate this...

Sensory ecology Animal supersensors

-dogs -turkey vultures used to find CH3CH2 SH -canaries -tempest prognosticator

Why be bold?

-faster growth -earlier reproductive opportunities -more reproductive opportunities? (Is being bold a choice?!)

Bio-inspired sensing

-mantis shrimps! -fiddler crabs

Some suggestion that infected bees deliberately seek lower temperatures to delay development of parasite

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Sounds can easily be modulated, making them excellent for communication

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Animals that use vocalisations may adapt calls to environment

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Aggressive displays are highly ritualised as exemplified by jumping spiders...

...and by stalk-eyed flies...

How animals communicate has to be viewed in the context of their own sensory ecology...

...and not just within anthropocentric frame of reference Studies of wild chimps suggest that chimp communication is not best understood in the ways we have approached this! We communicate verbally and with supporting visual cues How animals communicate may be very different If we are to understand - this is fundamental

Rather than teaching them our language...

...we should invest time to learn theirs Example: Elephants Cornell's 20 yr study of elephant communication Spectrogram used in order to detect infrasonic frequencies Ultimate aim to translate to an elephant dictionary

Signals may be:

1. Adapted from existing behaviour 2. Physiological/Autonomic responses 3. Displacement activities

Two evolutionary pathways for signals

1. Based on the sender - signal adapted from existing body structures, physiology or behaviour - sometimes called protosignals • Protosignals can be formed almost any behaviour pattern, anatomical structure or physiological change • Protosignals then undergo ritualization 2. Based on receiver - signals evolve that exploit receiver‟s sensory biases and ability to detect some information better than others These evolutionary pathways are not mutually exclusive

Swarm intelligence

1. Individuals independently acquire information 2. Information is combined and processed through social interaction 3. A cognitive problem is solved in a way that cannot be implemented by isolated individuals Sometimes referred to as the 'wisdom of the crowd'

Animals use signals in a range of behavioural contexts, including:

1. To facilitate recognition (individuals, parents, species etc) & social ties 2. Reproduction (courtship by males, female choice/ receptivity (e.g, acceptance or rejection) 3. Agonistic interactions and the establishment of social status Remember - in each case the strategic signaller is trying to increase its own fitness

Brainjacking and zombification: Why might parasites evolve mechanisms to influence host behaviour?

1. To maximise their own reproductive output 2. To increase likelihood of transmission

When are honest signals likely? Four circumstances under which we expect to see honest signals:

1. When senders and receivers share overlapping goals 2. When signals indicate something about the sender that cannot be faked 3. When signals are costly to produce 4. When dishonest signallers can be identified

Rules of interaction

1. Zone of repulsion 2. Zone of orientation 3. Zone of attraction

If approached by a predator that can only eat one group member, risk is

1/n

Average payoff to submissives

10 (1-a)

Fast AND Accurate Decisions in Fish

A 'good' decision has two main components - accuracy and speed Given a binary choice between a 'good route' and a 'bad route' how accurate are fish shoals? and how fast are they to make the decision?

Behavioural Modifications of Host Behaviour by Parasites

A host may still look like a host... ...but it's really a parasite genome expressing behaviour via body of host Does a host have free will? Do you...?! IMPORTANT CAVEAT!

Tit for Tat

A strategy of cooperation can emerge if there are repeated encounters and opportunities for reciprocity Nice, retaliatory, forgiving and clear Biological example of Tit for Tat Cooperation when challenging predator in sticklebacks (fish) Encounters predator to protect plant Cooperating mirror (shows fish going towards predator) Defecting mirror (shows fish going away from predator)

A rapid exit can be achieved in more ways than one

A sudden move is good; a surprising move is better; leaving the environment is best! Springtails Prawns Flying fish Octopus Special lizard Mousedeer and toads

Parasitism:

A symbiotic relationship between a parasite and its host • Non-mutual: the parasite benefits from relationship, while host pays cost • One or more stages needing a host • Parasitic & free-living stages • From across all Phyla • Simple & complex life cycles • Hyperparasites

What is a signal?

A unit of information transmitted from one individual (the source) to another individual (the receiver) which is designed to influence the behaviour of the latter

Evolution of cooperation requires either

Ability of animals to recognize each other Repeated encounters as in mutualisms

Spite

Actor and receiver pay cost

Cooperation

Actor and recipient both benefit

Selfishness

Actor benefits, receiver is harmed

Predator adaptation and prey counter-adaptation - arms race

Adaptations of prey and predators are dynamic & under powerful selective pressure! Van Valen's 'Red Queen Hypothesis': species have to 'run hard to stand still' Examples: Bats and moths - ultrasonic hunting - enhanced hearing, sonar jamming, furry bodies - frequency shifts and abandonment Snakes and salamanders - tetrodotoxin - tetrodotoxin resistance - more tetrodotoxin! Unguligrade running Humans and antibiotic resistant bacteria?

More ratios

Adult Sex Ratio • Operational Sex Ratio

Parasitic flatworm, Leucochloridium paradoxum

Adult stage (distome) releases eggs, excreted by bird Eggs eaten by snail, hatch into larvae: miracidia Miracidia travel to gut, develop into sporocysts Sporocysts travel to antennae, form brood sacs filled with cercariae Broodsacs are highly conspicuous to birds, which eat them

Thorny-headed worm, Pomphorhynchus laevis

Adult stage in host intestine Embryos released in faeces Larvae develop and are eaten by crustacean intermediate host Develop into cystocanth Intermediate host consumed by definitive host, lodges in intestinal wall, develops into adult

Lamprey control

Agnathan fish - not leeches Locate prey by smell Attach to live fishes Invaded Great Lakes in early 1900s and threaten $1.5bn p.a. industry Migrates using pheromones... •Firstly larvae •Then nesting males, then females Traps baited with pheromone much better than lampricide!

In some animals - two different sets of detectors and brain pathways - probably evolved separately.

Air-borne chemicals or fluid-phase chemicals (pheromones).

Electroreception

All living animals produce a discernible electromagnetic field Sharks are capable of detecting this, usually for hunting purposes This can be used against them!

this approach has proven valuable in a number of animal taxa

Allows a starting point in the examination of the inter-relationship of ecology and behavior from comparing social organisation to examining WHY animals group.

Male guppies display near more subfusc rivals

Also carotenoids important in display - so up-regulate melanin!

Locusts

Also examples of animals which undergo a dramatic shift from being almost entirely solitary to being gregarious Transition caused by...tickling Precipitates massive physiological changes - brain increases in size - start producing pheremone Feeds into behavioural change

A key concept: Evolutionary Stable Strategies (ESS)

An Evolutionary Stable Strategy is a strategy that cannot be invaded by a new (mutant) strategy Submissive individuals do well in populations with many aggressive individuals Aggressive individuals do well in populations of submissive fellows A mixture of A and S is likely to be stable (see word doc for table)

Three simple steps to prove

An animal's relative predation risk is proportional to it's domain of danger This results in compact groups Animals move towards their nearest neighbours to reduce their domains of danger This results in compact groups

Proving the points

An animal's relative predation risk is proportional to it's domain of danger This results in compact groups Animals move towards their nearest neighbours (using simple rules) to reduce their domains of danger This results in compact groups

Domestication - the longest application of behaviour?

An inherited predisposition towards humans Select for behavioural characteristics - Select against aggression and for 'tameness', docility, submissive behaviour Compare behaviour of wolves against dogs, or of wild versus domesticated cattle (or bovids generally) Russian experiment on red foxes began in 1959 - by 20th G, one third domesticated - As of now, 80% - Interesting pleiotropic effects

Some ambush specialists can actively lure their victims toward them

Angler fish have fleshy, sometimes bioluminescent growths on forehead

Different kinds of animal social aggregations, part 2

Animal groups may have stable membership or dynamic membership - may freely accept outsiders, or completely exclude outsiders If there are restrictions to entry, the decision to allow entry to the group may be based on relatedness (e.g. eusocial insects) but there are exceptions to this. ...or they may accept outsiders in some contexts, but not in others

Adapted from existing behaviour

Animals begin behavior patterns with characteristic movements that prepare them for action Example 1 Wolf pulls back lips and bares teeth before biting Improves another wolf‟s fitness if correctly interprets bared teeth Example 2 Pre-flight & predatory behaviors ritualized in gray heron for courtship

Learning what is & what is not a threat can be done through direct experience (dangerous) or indirectly

Animals can learn socially by observing response of others to (esp) visual or chemical cues Relies on classical conditioning - the response to conspecific alarm is relatively hardwired Chemical cues often used by animals - allows longer range learning!

Many Wrongs Can Make a Right

Animals may have different directional preferences If they are in a group and each compromises, then accuracy of the mean travelling direction increases with group size Experimentally demonstrated in pigeons and skylarks

Using illusion

Animals use illusion in visual signals Like the lizards - stand out against physical background, animals also use social background... Male fiddler crabs display near specially chosen male rivals Fool chickens, humans, and dolphins...but you can‟t fool baboons (and pigeons....)

What could influence the type of parental care given? Does it all come down to size?

Anisogamy

Examples of Self-organisation Ant trail following

Ant departs nest, explores local environment looking for food After finding food, ant migrates back to nest leaving pheromones behind Migrates between nest and food, each time building up more pheromone Other ants pick up the trail and gradually the trail is reinforced by additional pheromone Gradually lots of trails form Some get reinforced, others fade away

Trap builders

Ant lions dig pits Funnel webs Spiders webs - work using glue and -ve electric charge (because flying insects pick up +ve electrostatic charge) -Tensile strength and extensible -Built in toxins -Ant repellent

Evidence that V1aR is responsible for monogamy in prairie voles

Antagonist to V1aR reduces pair bonding Transfer of gene into mice makes the mice behave more like prairie voles - they become monogamous Vector-transferred upregulation of V1aR causes mountain voles to seek their partners and cuddle them The promotor region of Va1R contains a microsatellite that is long in prairie voles and short in montain voles Length of microsatellite is related to cuddling behavior in males. Variation in the length of the microsatellite is not the generalized cause of monogamy

ant trail following

Ants can be given simple problem to solve, for e.g. two routes between nest and food If routes differ, ants have to make a choice. If one route shorter - gets chosen

So, how good are ants at solving problems?

Ants given one hour to solve the maze after which researchers blocked off paths and opened new areas of maze to test ants' dynamic problem solving ability

• Ontogenetic shifts in diadromous fishes

Appears to occur at least partially independently of environmental cueing = more efficient

Predator adaptations to overcome large prey

Approx 10% of predators attack prey larger than themselves Epomis beetles - specialists in tackling amphibians Killer whales - Orcinus orca - hunting whales Komodo dragons

Parasites are diverse and ubiquitous:

Approx 20% of all known species are parasites (or more) • Conservative estimate - animal upon animal parasitism evolved min 60 times (also found in plants & fungi) • Numerous - Lafferty's estuary study found mass of parasites equalled that of fish and almost 10 times as much as the birds • Ubiquitous - are there any individual animals without parasites? Think about that when you next do an ecology study

Alcohol and aldehyde dehydrogenases

Approximately 50% of east Asians inherit inactivity of the mitochondrial form of ALDH 2 of six genes for human ADH are polymorphic High activity form is common in east Asians

Evolution of behavioral genes

As a whole behavioral syndrome, 'monogamy' seems too complex to be controlled by a single gene Easier to imagine a suite of behavior present in all voles, but the threshold required to elicit response is genetically variable

Anti-predator advantages of group living

As group size increases, individuals can decrease their own vigilance without increasing the risk of failing to detect an attack - a benefit to the individual's time budget ...but before the prey animals get too relaxed...predators have developed a counter strategy

Animal 'personality'

Aside from controversy associated with personality research... ...underlying fact that there are consistent differences in animal behaviour Consistent individual tendency to accept risk to gain reward - correlates across contexts Continuum across a given population - ‗bold' individuals to ‗shy' individuals Bold individuals = high risk, high reward & v.v. Consistent relative to one another over time, but not absolutely consistent

Strategy for multiple encounters

Assumptions: • No enforceable threats or commitments • No means to predict a future move (via facial expressions etc). • No way to eliminate a player or run away • No way to change the payoffs

Visual Acuity

At last - one we're good at Dog optic nerve has 167,000 nerve fibres compared to 1.2 million in a human In good light, humans compare well - in relation to us horses and sheep have 50-60%, dogs have 40% and cats have 20% of our acuity

Crypsis isn't just about vision!

Auditory camouflage - are furry moth bodies a defence against echolocating bats? Chemical camouflage -Parrotfish -Limpets -Biston robustum

· Offspring favour:

B/C = ½ · i.e. continuation of parental care until the cost to the parent is twice the benefit to itself.

· Parents favor:

B/C=1

Often a conflict of interest between sender and receiver

BUT on average, both parties must benefit from the exchange, otherwise signalling system would not be stable (Maynard Smith & Harper, 2003). If senders manipulated receivers too well, then receivers would be selected to ignore senders. So, signals must carry info of interest to receiver & this info must be correct often enough for receiver to be selected to respond to it

Characterise and identify sequences probabilistically - predictive text & speech recognition

Based on how they're moving, we can tell all sorts of things...

Can sometimes see active recruitment - increase in activity prior to a move Process begins when a single individual attempts to initiate a move Others then decide whether or not to join

Based on this, initiator decides whether or not to continue

Attack is the best form of defence!

Be frightening - swell up to large size Be threatening - snakes, funnel webs etc Venomous animals often reluctant to attack - costs of injury are significant! Black widow used silk as a first line of defence against rodents

Thanatosis

Be less appealing - play dead! Many species engage in this trickery inc lizards, moulting spiders etc Virginia opposum backs up its signal Heart rate drops, body goes floppy, Starts drooling, urinates and produces a terrible anal secretion

WHY?

Because it pays loners to join groups

Preventing detection

Behave in such a way as to reduce conspicuousness - think back to guppies This can be done more formally as... Crypsis Matching background colouration Widely used across taxa Only works effectively if animal moves at the same speed as background - often this means not at all In addition, animals generally have characteristic body shapes Necessitates edge/form disruption

Nature and Nurture

Behaviour is influenced by both genes and the environment Extent to which genes control a behaviour differs from one behaviour to the next Example: Alcoholism can be broken into two behaviours teen onset alcoholism = genetic adult-onset alcoholism = environmental

Displacement activities

Behaviour which has no direct link to the context Caused when animal has conflicting motivations and is thus indecisive Faced with an aggressor, an animal may have conflicting motivations e.g. to fight and to flee so may instead preen Courtship often involves conflicting tendencies - Sexual partners must come together to mate in spite of aggressive tendencies that keep them apart

Helpers in cichlid fish

Best behavioural strategy when predators are around By-product mutualism

What is a cue?

Broadly, a unit of information collected by an individual that influences its behaviour. May arise from biotic or abiotic source

Reproductive interference

Brood parasitism, Extra-pair copulations Reproductive suppression

Bowerbirds are the masters of this..

Build elaborate bowers for courtship Male great bowerbirds use complex visual trickery including „forced perspective‟ Makes court seem smaller and displayed ornaments greater When female turns head, this illusion changes - but maybe not deception...female may be choosing

In the related Japanese lichen moth, males try same trick

But females can tell calls apart, so retain control over mate choice

Many other mammals have more taste buds (= more sensitive taste) than us:

But not chickens, or snakes You lose taste as you get older (thereby explaining sprouts...!) Massive variation between humans Sex differences - why?

...man as predator Bycatch is a HUGE problem

But researchers noticed that fish and prawns behave differently when confronted by trawls....

Closely related species often have considerable overlap in song patterns

Can be confusing when ranges overlap Study on warbler spp showed that both species reduced variation where they overlapped Equivalent of enunciation?!

'Classic' parasites

Can be divided into endoparasites and ectoparasites

But what about groups where individuals do have information?

Can informed individuals guide the behaviour of the group

Many other animals - birds, insects, some fish - have more types of photoreceptors = more sophisticated colour sense

Can see in UV spectrum Birds produce oil droplets in eye which increase colour perception Some have photoreceptors sensitive to extremely short λ in UV range. Allows detection of polarised light even when the sun is not actually visible. At other end of spectrum some snakes can detect infra red = body heat

Learn to recognize faces

Can't tell difference b/t telletubbies bc all have same face

Emerald cockroach wasp, Ampulex compressa

Carefully selects a victim and delivers two stings to the cockroach's brain First sting causes brief 2 - 3 minute paralysis, allows wasp to perform The second sting requires much more precision - hence the need for the first... Wasp injects directly into the sub-esophageal ganglion Actively searches with its ovipositor for this region Amazingly specific effects on cockroach locomotory ability

Bats are extremely good at detecting insects!

Carried out at high speed detection to capture takes less than 0.5 seconds. The wing-beats of insects affect the patterning of the returning echoes - bats can determine insect species Dolphins differ in that they use broader band calls (or clicks as they are often called) which are effective over longer distances Produce sounds through nasal passages & hear through lower jaw linked to the stapes bone (dolphin's ear opening largely vestigial).

Weaning conflict in cats

Cat mother stops giving milk but the offspring beg for attention and milk, creates conflict

Strange location of taste receptors across the animal kingdom

Catfish - on barbels and outside of body - a super taster Insects - flies, butterflies etc etc

Vigilance

Central to any predator's strategy is to minimise the distance between itself and the prey before it is detected. Sociality counteracts this because of the classic 'Many Eyes' theory

Who's got the best sense of smell?

Chemical cues are essential for courtship behaviour of many fishes Esp. important in the deep sea Massive space - sparsely populated & dark Requires incredible sensitivity Male silkworm moths and female attractant pheromone Salmon use an imprinted chemical memory of home Most birds hopeless BUT not all. Turkey vultures and broken pipelines

Preventing attack

Chemical defences - an excellent deterrent used by many small, delicious animals Not many mammals...but skunks are impressive! Aposematism - signalling poisonousness Widespread - nudibranchs, seasnakes, caterpillars & many others Important to be conspicuous! ...but this represents something of a paradox. How did it evolve in the first place?

Siblicide in great egrets

Chicks fight vigorously, the biggest often killing the smaller chick Parents do not interfere

Proust Effect

Close anatomical ties of olfactory system to limbic system and hippocampus

Animals can adapt behaviour and phenotype in response to changes in threat level

Common frog tadpoles grown in the presence of a key predator developed wider bodies and shorter and wider tails In addition, they were less active swimmers than those reared without predators This is good defensively, but has costs BUT, when predators removed, the tadpoles switched back quickly

The Hawaiian Monk Seal

Complex interactions between four different species Effective tagging and surveillance proves crucial

Evolution of aggressive interactions

Consider a population of aggressive and submissive individuals When two individuals meet the outcome depends on the genetic tendency to be submissive or aggressive The payoff for the attacker depends on the strategy (flight or fight) the opponent adopts

Predator adaptations to physical defences

Crows drop shells Wolf fish, crabs and lobsters crush them Whelks drill through them and Mantis shrimps punch through them Second leg is heavily modified - gives rise to the distinction between 'smashers' and 'stabbers' Trap jaw ant is faster - but mantis shrimp packs much more of a punch!

'Know Your Enemy'

Crucial for animals to be able to recognise danger!

Host birds watchful when cuckoos nearby - cuckoos adapted to work quickly

Cuckoo removes a host egg and replaces it with one of her own Cuckoo chick develops quickly and hatches a day before host eggs - can then evict host chicks Result - strong selective pressure for hosts to be able to recognise cuckoo eggs and chicks!

Just because they‟re passive, don‟t think that cues cannot be extremely powerful!

Cues can exert powerful subliminal effects on animals, including us... Pizarro‟s fart experiments - disgust and tolerance Faulkner‟s disease experiments - pathogens and xenophobia Alt., certain cues can be used to make us more amenable - coffee, bread, supermarket lights Same applies to animals - cues exert powerful physiological and behavioural influence - e.g. ammonia and aggression But while cues provide vital information to animals, signalling is at heart of communication

Example

Cymaglyphs are sonic representations - imprint of dolphin vocalisation in aquatic env More intricate and more ecologically relevant than usual spectrograph approach Sometimes called „picture words‟ Offers opportunity to understand by translating from their modality to ours while retaining complexity Approaches like this may represent way forward

Preventing attack

Deimatic displays can be non-visual esp. auditory Some animals produce ‗distress calls' - but these not recruitment calls Coyotes presented with starling distress call showed startle response & increase in attack time compared with those in the no-call trials Walnut sphinx caterpillar Peacock butterflies (Inachis io) produce hissing sounds and high-intensity ultrasonic clicks & cause predatory rodents to flee Hairy frogs can pop claws out...

Among vertebrates, birds have probably best vision

Density of photoreceptors critical in determining max attainable visual acuity: Humans approx 200,000 receptors/mm2 Sparrow has 400,000 Common Buzzard 1,000,000 Raptors have phenomenal visual acuity - 8 times greater than a human.

Vervet monkey alarm calls

Different alarm calls for leopards, eagles, snakes and baboons Infant monkeys give indiscriminate alarm calls but eventually learn to give the right call at the appropriate time

Cuckoos

Displace hosts‟ young Signals are extremely powerful: -Gape -Begging calls mimic sound of entire brood = supernormal stimulus

Nice experiment with mealworms and card!

Disruptive patterns increase survival beyond a cryptic pattern, which in turn survives better than plain black or brown wings

Social aggregations

Distinction between social aggregations and other forms of animal aggregations ...Social aggregations are not the same as resourcebased aggregations If a given resource is clumped in time and space, animals that require that resource will also... ...but these are not true social aggregations

probability that your group will give you close to the right answer

Diversity, not expertise, is the key!

Wild Dolphin Project - Denise Herzing

Dolphins taught sounds for objects Recorded and analysed sounds made by wild dolphins Use pattern-discovery algorithms, analyse dolphin whistles and extract meaningful features

Blue-footed boobies have brightly coloured feet

During courtship ritual male lifts his feet to display them to the female Blueness of feet indicates condition Females prefer males with brightly colored feet

General principles of sensory systems

Each main sensory system has specific receptor type Receptor converts external signals from the environment into electrical impulses for the brain to interpret, for e.g. Chemoreceptors Mechanoreceptors Photoreceptors

'umwelt'

Each organism experiences a different and unique perceptual world as a result of its sensory apparatus

What happens when a predator attacks?

Each selfish individual attempts to try to reduce its own domain of danger Causes group to contract in size Selfish individuals try to put others between themselves and the threat!

How organisms perceive and filter information from their environment varies widely

Each species has a sensory apparatus that has evolved in line with ecology Is our sensory experience an absolute reality or a relative and highly subjective one. Artificial sensors detect chemical molecules, light particles, sound waves and electromagnetic energy beyond our own capacities - but in most cases these inferior to those of animals

Selection for tameness in the red fox

Easy to select for reduced bites

Do effective courtship signals deter rivals too? Or might they alert a rival, or a predator?

Eavesdropping! A signalling animal always runs the risk that it's signal can be intercepted by individuals other than mates One way to minimise the cost of this is through directionality, but it remains a major cost to signallers...

Examples of Prisoner's Dilemma situations in human affairs

Economic Political Military

Accurate locomotion

Encoding a spatial map can be difference between life and death! Prey animals often have excellent local navigational abilities -Frillfin goby -Elephant shrew/sengi This is one reason that translocated animals often display stress in a novel environment - stripped of a major defence

Predator confusion

Encountering a large group of prey animals can cause sensory overload

Signals may be costly

Energetic costs are the most common measurements Oxygen consumption increases in insects and frogs Male guppies die young

Cordyceps fungus - ant brainjacker

Ensures environment at perfect temp & humidity Height maximises distribution of spores Growing market for food and for medicine

Other ways to stand out against the background...

Environmental structures move in characteristic way in wind: Sinusoidal oscillations Anolis lizards signals fit a square wave profile - makes their signals stand out! Lizards also change behaviour as environment changes Jacky dragons display faster and flick their tails more when it is windy and the vegetation moves

But while honest signals predominate, dishonesty does exist

Esp. where senders and receivers have different goals Asian corn moth - males have learned to copy bat echolocation calls!

Why do they matter?

Every offspring has two parents

Agonistic interactions

Everything to do with contests and aggression between individuals. Threat displays highly distinctive - high cost to being misunderstood Aggression and submission signals Size is often a good predictor of strength in the animal kingdom - aggressive displays often emphasize this Aggressive displays often emphasise weapons - bare teeth, spread claws etc

'comparative method'

Evolution of different species in relation to different ecological conditions Comparing between related species might promote understanding of how distribution of foods, or predation threat, affect the social tendencies of species

Kin selected altruism: Kamikazi sperm in wood mice

Evolution of social behaviour in haplo-diploid insects

How many leaders do you need to lead a group?

Examined using mathematical model

If a signal is directly related to the signaller's quality, it can't be faked...

Example : Rival spiders encounter conspecifics on web- assess each others' weight before engaging Lighter spider retreats Experimental augmented weight of some spiders (Riechert 1978, 1984) Example : Like many mammals, male deer vocalise during courtship and threat Length of vocal tract ∝ body size, so roar gives choosing females honest info

Innate behaviour example

Examples: turtle hatchlings; honeybees dance Simpler behaviours: primate grasp response are reflexes and are also genetically determined We are more likely to help youth of another species (instinct, no learning)

Evidence exists for both

Exercise changes personality Warm lizards allow pred to get nearer before flight

Say n=2 and the number of females is half the number of males

Expected gain (in terms of offpsrin) per male is (2 x 20 females)/40 males = 1 lesss selected for males (2 x 20 females)/20 males = 2 same reproductive selection and only ESS over time, highest fitness on average

Brood parasites

Exploit parental care of con- or heterospecifics

Foraging trade offs

Exploration versus Exploitation Food Quality versus Risk

Problems with determining optimal group size

Fails to account for complexity of species - as in lion example Similarly, determining group size fitness function is difficult Optimum is context-dependent and dynamic - changes in time and space Fails to account for inter-individual differences both state-dependence and dominance Mostly involves free-entry groups

Predator adaptations to outsprint prey

Fastest animals on land, in air and underwater are all predators Peregrine falcon (390 kmh) in a stoop (terminal velocity could be higher than this...for humans only 200kmh, but raptors more aerodynamic) Eurasian hobby 160 kmh Black marlin 130kmh Cheetah 120kmh - acceleration incredible Australian tiger beetle Cicindela eburneola (171 BL/s or 1.86m/s) - causes visual processing problems

Maternal effects

Female field crickets exposed to pred cues ‗warn' eggs prior to being laid When offspring tested, exposed offspring were more wary (refugia) than controls Survivorship greater in exposed group Exposing already laid eggs, or nymphs, to spider cues made no difference - clearly a maternal effect

glyptapanteles & Thyminteina

Female oviposit into caterpillars Caterpillars continue developing and feeding until parasitoid larvae emerge Larvae pupate... not all larval Glyptapanteles emerge from host. One or two remain behind and active... Somehow guide caterpillar to stem of plant and cause it to undergo behavioural changes -stops feeding and moving -more head-swings upon disturbance

Siblicide in boobies (Masked booby)

Females lay a two-egg clutch (2nd egg is insurance) · Eggs are laid 2-10 days apart older chick pushes younger sibling out of the nest within 2 days after hatching · Siblings push each other out of nestg

Baited Feeder trials

Field work at Pearl Beach, NSW • Set up feeder for high and low quality pollen/pollen analogues (8 treatments) • Train bees to feeder • Film returning forager dances for computer analysis

Swarm intelligence increasingly being used by governments and by private companies

Financial crash prompted rethink of hierarchical management structures Use of prediction markets has grown - combination of individual forecasts to achieve higher forecast accuracy Can be used for predicting elections, markets or sporting events - winners get rewards. Traditionally, large design departments come up with new product ideas. Lego instead created internet platform called 'Mindstorm' Users talk about design ideas, showcase work & vote on each other's designs. Outcome has been highly creative new designs!

So, what is the basis of an animal social aggregation?

Finding watertight definition of what social aggregation IS that applies to all species difficult BUT True social aggregations usually involve social attraction Also, animals in social aggregations must be able to communicate - they need to be in sensory proximity

Parents encourage siblicide

First eggs contain higher levels of androgen: first chicks more aggressive Incubation starts as soon as first eggs are laid: first chicks will be bigger

One way to prevent capture, or limit damage, is to misdirect a predator's attack

For example, lizards can shed tail. Autotomised tail wriggles to attract pred - allows escape A number of insects have false heads The insects also perform 180° turns after landing to confuse observing birds Misdirects attack AND gives pred a surprise when animal moves wrong way

Great tits have a large geographic distribution

Forest dwellers in comparison to open woodland birds: - lower frequency - narrower range of frequencies - fewer notes per phrase Human activities alter signalling environment Urban birds sing shorter, faster songs with higher min frequencies -sing at higher pitch to overcome traffic noise

In Lake Victoria, blue light more easily visible in shallow water and red light in deep water.

Gene expression varies with depth: females are most sensitive toward blue light near surface but increasingly sensitive to red light with depth Male cichlids have tuned their colourful courtship to match their audience

Consequences of the King's behaviour

Given an equal sex ratio and the fact that each offspring has 1 mother and 1 father, the reproductive success of males must be.........

Predator adaptations to chemical defences

Grasshopper mice are immune to the venom of many of their prey spp Have an interesting strategy to deal with spraying beetles Skunks roll their prey around under their paw

•Co-operative hunting - strategic predators!

Group hunting allows access to much larger prey...but it's only teamwork if different individuals fulfil different roles, e.g. lions, chimps & killer whales

Evidence for optimal group sizes in nature

Group hunting in wild dogs Larger packs kill larger prey, have higher capture success, and travel shorter distances in a hunt but must share kills with more members of the group

Predation as a selective force Guppies in Trinidad

Guppies in Trinidad On Trinidad, guppies live in streams that differ in predator spp that they have to contend with. Some stream sections are high-predation environments (see pic), others low-predation - can be adjacent, but separated by nat features.

"Proximate" Questions

HOW Cause & Development Comparative psychology and ethology ›

From the predator perspective:

HOW do they detect the shoal and co-ordinate their attacks? WHY do they hunt in groups?

Sociality and the sardine migration From the prey perspective:

HOW do they manage to be so synchronised and cohesive? WHY do they continue to shoal?

Also affects their appearance and their behaviour

HP males smaller & more drab than LP males HP males invest less in courtship HP guppies shoal far more Transplanting guppies from HP to LP sites (and v.v.) allows exploration of evolution Transition between types happens quickly Going the other way: Feral guppies in Oz

Types of Learned Behavior

Habituation Imprinting Classical conditioning Operant conditioning (instrumental learning)

Costly signals What prevents a male from exaggerating his qualities?

Handicap principle: - signals that are costly to sender are favoured by receiver - only the best individuals can afford to produce those signals The signals are handicaps!

Aversive conditioning

Has been used for over 100 years! - Tigers and man Distasteful chemicals added to foods - foxes & pheasants - snakes and bird eggs - quolls and cane toads

Kin selected altruism: Helping in the bell miner

Helping behaviour tends to evolve when a single pair cannot successfully rear chicks

Ultrasound

High frequency sounds are better for short-range communication since they are easily reflected by objects and localised. Large numbers of mammals use ultrasound frequencies to communicate In many cases high frequency used for distress

Enlisting other species

Hosts can enlist other species to remove parasites that they cannot remove themselves These may be specialised or non-psecialised: - Anting by birds - recorded in 200+ species - Oxpeckers - Cleaner wrasse

Foraging and economic decision- making

How can we use economic analysis of costs and benefits to understand animal behaviour?

The development question:

How did the behaviour arise during the lifetime of the individual? How does the environment influence the development of this behaviour?

The evolution question:

How did the behaviour evolve over the evolutionary history of the taxon?

"Kindchenschema"

How to be 'an infant worth rearing' • Innate releasing mechanism for care- taking behaviour • Elicited by features of dependent young - Large head relative to body - Big cranium compared to facial bones - Large eyes - Soft-elastic surface texture - Round and protruding cheeks

Eusocial insects

Huge diversity of ants, bees, wasps and termites, many of which are eusocial Form the most highly organised societies in the animal kingdom Division of reproductive labour and also often a more intricate caste system

Why have colour vision at all?

Humans & other primates perceive colours by having cone receptors sensitive to light of 3 wavelengths, red, green and blue (trichromatic vision). May have evolved to allow primates to improve visual resolution and to distinguish between different coloured fruits and leaves more easily (back to that in a moment) Many mammals only have two receptors (dichromatic). BUT dichromatic vision better for detection of movement (which is clearly important for most animals)

Predators are Terrifying!

Humans one of the few species that live without significant risk of predation This affects our understanding Animals live under risk! Pitcher estimated that shoals of minnows never > 2m from pred They have adapted to deal with it How? One way is to be fearful but that carries costs So animals have to balance risk against rewards...

But how do animals know where they are in a group

Hungry animals move faster. As they become sated they slow down - typically simple explanation

Vervets will occasionally try to cheat

If a dominant individual is eating, subordinate may call out that there is a rival group approaching Males will sometimes try to entice females by making a 'food' call - will then try to mate BUT members of a social group stop believing an individual that gives unreliable signals

Why?

If group splits, all may lose benefits of group membership

Animals signaling can only be stable if the signals are honest

If the bees could not back up their threat signal, the wasp would fail to recognize the signal as a threat and it would call bluff and attack the bees. The heat balling is costly, so they can't do it all the time. The signal prevents them from having to. The predatory-prey signaling benefits both parties.

Animal communication

If we can understand their communication, we can understand them ...but we can also understand them by watching their trajectories...

Domains of danger and the Selfish Herd

Imagine a group of animals (represented by dots) moving in 2D Each animal has a domain of danger For 2D groups can use Voronoi tesselations to visualise... We may have UDOD or LDOD

Evolution of cooperation among non-relatives

In a population of creatures that interact just once, the best strategy is not to cooperate on any encounter Seagulls

Herring

In common with many pelagic schooling fish, herring spend their entire lives in close proximity to conspecifics The obligate nature of their social behaviour is evidenced by the fact that if isolated they die

Potential problem?

Increased hunting success * Assume everyone searches for food, everyone pays cost of searching and gains for food, but can cheat and not suffer cost and only gain Beneficial to the solitary lion; can be detrimental to the group Parasitism!!!!

Predator adaptations to capture prey

Incredible weapons! Cetaceans use bubble netting and... ... a ‗sonic boom'? Velvet worms imitate Spiderman (or v.v.!) Bolus spiders Sailfish uses rostrum as lance

Toxoplasma gondii

Infection changes behaviour of intermediate host in a dramatic way...

Behaviour

Infection increases searching behaviour, increasing likelihood of encounters with predatory definitive hosts Parasite increases host serotonin production Serotonin controls searching behaviour

Producers and scroungers

Information transfer suggests a co- operative network, but this is the real world An example of game theory

Self-medicating behaviours Zoopharmacognosy

Ingestion or application of substances to kill parasites or discourage them from settling Olive baboons eat leaves of Balanites aegyptiaca to kill Schistosoma blood flukes Anecdotal evidence: brown bears apply osha roots (Ligusticum porteri) to fur to repel blood-feeding insects

Predator interference

Injured fish give off a powerful chemical smell, known as 'Schreckstoff' Schreckstoff attracts other predators, which increases handling time

Insight learning

Insight learning occurs where an animal uses cognitive or mental processes to associate experiences and solve problems Example: Wolfgang Kohler's work on chimpanzees that were trained to use tools to obtain food rewards Some amazing examples of insight learning come from corvids....

Male-Female conflict:

Insulin-like Growth Factor (IGF)

· Greater Male Variability Hypothesis:

Intellectual abilities are more variable in males than in females. There is both an excess of males among the mentally defective and very few female geniuses o Selection for bigger brain size, more intelligent o Same median intelligence in males and females but more variation in males (can be extremely dumb or extremely smart)

What's the difference between cues and signals?

Intention on part of sender -Signals are attempts to communicate -Cues are often by-products of behaviour or physiology

Asymmetries of relatedness

Interbrood conflict: Intrabrood conflict

Animal 'personality'

Interesting - comparing between populations Predator sympatric predators bolder than predator allopatric populations... Predator-prey experiments - ‗shy' individuals often lose out... How? Why? Still researching this... Answer likely to lie in physiology

Eyespots are used by many animals to misdirect attack

Interestingly, development is plastic; occurs in response to predator exposure Evidence exists that eyespot functions to increase survival

Siblicide in fish!

Intrauterine cannibalism in grey nurse sharks Begin with 12 embryos but birth just 1 or 2 live

Refuging behaviour need not involve hiding

It can simply be going to a part of the habitat where your predator cannot follow Out onto thinnest branches, or up a cliff... Clownfish - famous association with anemones Anoxic environments - Haplochromines in shallow Lake Victoria wetlands

Social information is extremely valuable in this context!

It'd be nice to do this experiment on non-human animals...

stotting in springbok

Jump in air when cheetah comes, signals that "I've seen you and I can run very fast for a long time, but the one next to me can't so go eat that one" Cheetah can't sprint all the time, very costly Why do the springbok attract the attention of the cheetah? Alarm signal: warning to others in the herd that a predator is present Social cohesion: if the bok flee as a group it makes it harder for the predator to cut one out Confusion: stotting may confuse and distract "I see you" signal: the bok tells the predator that it has been seen and can be outrun

Shoaling fish prefer to stick to their own kind How do they decide?

Juxtaposition of visual and chemical cues

UV may be a hugely important for many animals

Key component in signals of many birds ...and fruit Tactically, UV light contrasts strongly with colours found in woodland environment = good to get message across (Andersson et. al. 1998)

...or they can compete

Kleptoparasitism is a common phenomenon!

Loulis, infant adopted by Washoe, learned signs by observing chimps - chimp group communicated partly by signing

Lana trained on a computer (eliminates social cueing) Learned symbols called lexigrams Had to be used in an appropriate order i.e. basic syntax Good results - coined new words and phrases e.g. "Coke-which-is-orange" Sherman and Austin communicate with each other using lexigrams appropriately - can discuss basic problems Kanzi, a bonobo, has a wide vocabulary of 256 lexigrams Can lead to deception? The terrible case of Koko the gorilla....

Other examples of Self-organisation

Lane formation Flocks, shoals, herds and....crowds

Wasp leads cockroach to a hole

Lays an egg on cockroach and blocks entrance to hole Roach still alive at this point, just doesn't have will to move Newly hatched grub burrows into cockroach and eats it alive... ...but in a very specific order Before eventually emerging

Information transfer in evening bats

Leaders "produce", followers "scrounge"

Innate recognition

Learning requires experience, but experience can be fatal - 1st encounter could be last Requires sympatry in evolutionary time • Visual cues in fish and birds • Chemical cues in fish and amphibians • Auditory cues (song bird alarms) in brush turkeys (but not visual cues) Most studies find generalised response to certain qualities of objects - relatively labile predator recognition template in early life Sympatry requirement one reason introduced species such a problem!

Learned Behavior

Learning: 'a change in behaviour due to experience' The ability to learn is closely related to the complexity of an animals nervous system. This allows FLEXIBLE behavioural patterns

Learning

Learning: animals acquire an essential set of skills When do they learn? Continuous learning and critical learning periods 'Headstarting' - Mona island iguanas - Translocation of of jeweled geckos - Australian native fish in Centennial Park - Rufous hare wallabies run the length of cage - Even primates! Even just translocation can be tricky Critical learning periods - Painted terrapins in a rapidly changing habitat

Collective movements in humbug damsels

Live in discrete colonies featuring a range of sizes and ages Move between coral patches in their environment

Mantis shrimps can also be dishonest

Live in fiercely defended burrows If another mantis shrimp encroaches the homeowner signals readiness to attack Readiness to attack is signaled by a threat display Newly molted mantis is defenseless BUT still gives threat display Opponent is (usually) deceived and retreats Why? Cost of getting it wrong is high! Overall the signal is honest

Toxoplasmosis in rats and cats

Localised in amygdala Activates expression of dopamine Upregulates enymes in dopamine synthesis pathway High levels of MeApd activity in response to cat urine in infected animals

Squirrel combines modalities to warn off rattlesnake Is this deimatic?

Looks dangerous, but remember economics approach...

Infrasound

Low frequency sounds penetrate virtually everything - transmitted incredible distances. Communicate with each other over huge distances. Elephants can apparently detect other elephants stamping the ground in fear 10 kilometers away. Cetaceans have advantage that sound travels four times faster in water than air - locate each others calls even when hundreds of kms apart.

Manipulating hosts to move parasites around

Malaria Plasmodium manipulates mosquito in three main ways -reduces risky feeding -interferes with blood drinking -tinkers with chemosense of mosquito Nematomorphs Larvae of Gordian worms are ingested by cricket Worm then grows inside cricket until mature It then needs to get to water...how?

Egg spots in Rift Lake cichlids

Male mouthbrooding fish have egg spots on anal fin

Swordtail

Male sword acts as sexually selected signal - poss mimics gonopodium Sword exploits female receiver-bias...

Allogrooming

Many animals allogroom Social functions: - Affiliation reinforcement - Reconciliation - Courtship - Bond reinforcement Economic function: traded for food or sex -Crab-eating macaque females likely to mate with males who groom them

Refugia

Many animals avoid detection and/or attack by the use of refugia Can work well...but animals pay opportunity costs Caterpillars vulnerable to birds - so hide on underside of leaves But...birds hunt for caterpillars by looking at leaves (Why?!) Caterpillars without chemical defences keep leaf edges tidy. (Those with chem def don't)

Magnetoception

Many animals have sophisticated abilities to detect the earth's magnetic fields - insects, lobsters, fish, birds and mammals all documented Migrating lobsters tested in an electromagnetic cage

Status Symbols

Many birds have „badges‟ - relate to dominance Serves to allow rapid assessment of rivals - prevents escalations Is it honest...? Yes - relates to age and hormones Birds treat it as being honest - artificially marked birds given respect! ...and look where the signal is, where signals are generally

Predator adaptations to detect prey

Many predators have finely honed senses that enable them to locate prey: •Visual acuity in birds of prey - can also see UV. Does this help them catch rodents? Songbirds? •Hearing (and 'anti-hearing') in owls •Sensitivity of sharks to blood •Ability of snakes to see infra-red

Polygyne form

Many queens/nest Skinny Form new nests by colony budding Genes related to social behavior are over- represented in the social chromosome

Signals arising from Sender Protosignals

Many signals start as part of another behaviour or physiological response - takes on a signaling function later Signal over time becomes more stereotypic and fixed

Changers

Many species change their degree of sociality as they age, or across different seasons Many fish species are highly social as juveniles, but become increasingly solitary as they age Also found in crustaceans Others are social as adults, except during the breeding season when the sexes segregate and (usually) males become briefly solitary

Mixed Predator Strategies

Many species use a mixed pursuit and ambush strategy Use stealth to minimise distance to their prey followed by explosive speed over remaining distance Familiar examples include lions... Trumpetfish get up close to their smaller fish prey by ingenious means...

Life skills training for hatchery released fish

Massive mortality in the first few days Often little or no boost for popn Naivety in respect to: - Predators - may even be attracted! - Foraging - failure to recognise, to forage effectively, and even physiological entrainment - Orientation How studying behaviour has helped - Classical conditioning for predator recognition; also direct experience in Murray cod (or water pistols!) - Direct experience aids foraging; social learning also helps - Social learning and cultural transmission

„Light environment‟, specifically spectral bandwidth (colour) and intensity (brightness) changes across habitats.

Max transmission at: short wavelengths (blue) in clear pelagic seas intermediate (green) wavelengths in coastal waters longer (yellow-red) wavelengths in estuarine and fresh waters. Adaptations to the environment are manifest in fishes‟ retinal structures

Anecdotal report of stripes on Chionactis occipitalis appearing to move in opposite direction to snake's movement

May exploit peripheral drift illusion

Selfish herd theory

Model proposed an imaginary pond with frogs being attacked by a snake. Each frog acts to try to put another frog between it and the approaching threat

Genetic markers

Moderate heritabilities confirm a genetic component Large number of enzyme systems (particularly those related to alcohol metabolism) have been investigated HLA system on chromosome 6b - Associations are weak - Type 1 statistical error

Monkeys are spiteful too

Monkeys trained to trade a token for food reward (grape or cucumber). Monkeys prefer grapes, will throw cucumber away if get cucumber Two monkeys do the exchange simultaneously and receive an equal or unequal reward

Behavior controlled by a Mendelian gene

Montane vole M. montanus Polygamous Solitary Males do not contribute to offspring care Weak expression of vasopresson V1a receptor in brains

• Changes snail appearance

More conspicuous: colourful, pulsating, mimics caterpillar? Only pulsate in high light intensity: when birds are more active and brood sac is more visible

Why don't offspring beg more?

More likely to be found by predators, and very energy costing • reduces indirect fitness by reducing amount of resources given to relatives

Most of previous examples about intraspecific communication - what about interspecific communication?

More likely to see deceit? Less likely that goals overlap Predators and prey for example - though prey may use honest signals to deter pursuit

Learning can act to modify species-specific fixed action patterns

Most innate behaviors improve with performance as the animals learn to carry them out efficiently.

What is (animal) behavior?

Movement "Muscular contractions in orderly sequences"

What if getting to the best patch is dangerous?

Multi-objective foraging decision

Imagine scenario: prey animal detects approaching heterospecific

Needs to identify the animal and to respond appropriately Pressure is on animals to maximise ‗true' responses and minimise ‗false' responses Turns out that animals from no/low predation envs not as good at this - very jumpy!

Competition for food in fieldfares

Nestlings die primarily from starvation

Evolution of signals

New signals do not evolve from scratch (evolution & bricolage)

Collective consciousness?

No - each agent adopts simple rules

Human hunters

No weapons to kill from distance and not fast or strong enough for ambush Only reliable way to kill prey to run it down over long distance. Presistence hunting involves relentless pursuit of an animal such as a kudu in the midday heat. Hunters of central Kalahari chase a kudu for up to 5 hours over 25 to 35 km in temperatures of about 40 to 42 °C

The eureka moment...frustrating confounds

Non-predatory factors that may influence prey behaviour and position (eg. foraging, mating) Vigilance Confusion effect Sex Size Class Oddity effect Body condition State of hunger

animals need to adopt a precautionary approach

Novel/unfamiliar object may be a dangerous predator! Wariness/Neophobia → Habituation/Sensitisation Neophobia varies among individuals as well as among popns - highly stereotypical conflicted behaviour

Observational Learning

Observational learning & imitation Learning that derives from watching the behaviour of others In the UK, blue tits and robins learned to rob cream from the top of milk bottles during the early part of the 20th century, and later to puncture foil seals This involves imitation Social learning without imitation - breath-based food aversion in rats

Is social recognition in fish affected by exposure to environmental contaminants? Can fish recognise the chemical cues produced by their own species in the presence of these contaminants?

Odours flow into tank from each container and form 2 odour plumes (see dye) •Fish can't recognise the chemical presence of conspecifics at 0.5ug/l •Legal limits for 4NP vary...

Group Foraging

Often far more efficient than going it alone! - Finding food - Capturing prey - Increased time budget = more eating

Female cuckoos favour specific host species & lay distinctive eggs - cuckoo divided into genetically distinct strains „gentes‟

Often match host eggs very closely Extent to which these match eggs of their respective hosts depends on pressure exerted by host on signal Caveat - many birds susceptible to supernormal egg stimulus - predicts that it‟s good to be slightly larger, slightly more speckled!

Going Multi-Modal

Often, animals use multimodal signals - loads of examples: •Signalling spiders use visual and seismic cues •Salamanders back up visual signals with chemical signals •Aggressive crabs use mechanosensory and chemical signals

Olfaction - remote detection of chemical cues

Olfaction is incredibly important for a large and diverse range of animals

What does this mean?

On other hand many mammals have up to six times better visual sensitivity than us in the dark since they have many more rod receptors Also have a structure called tapetum in eye which reflects captured light back onto the retina to enhance sensitivity - makes eyes shine brightly in the dark!

Best eyes in the business?

One of the most complex visual systems Possesses loads of photoreceptor types! Polarised light sensitivity and independent eye movement Being used to inform remote sensing technologies

The Ultimatum game

One pair of a pair of subjects is given $10 The person given the money (the proposer) chooses the split Can give half to other person or keep it all or any ratio in between The other person (the responder) can agree to the split or refuse it in which case the proposer gets nothing Best strategy for the responder: Should accept anything because something is better than nothing Best strategy for the proposer: Should propose enough that they will agree to it, but nothing more More likely to punish human than computer for bad behavior : $9 to $1 Guys with higher testosterone more likely to reject

So how do animals get accurate information on what is and what isn't a threat?

One way is to collect social information Another (insane) way is to perform predator inspection! Approach a threatening organism in their habitat and gather information about: •Level of satiety •Its prey preferences From this, prey animal can assess level of risk Predator inspection is risky - so why do it? It's also sexy - that's (at least partly) why

how does an animal know how big its group is?

One way is to follow a simple rule to increase or decrease distance to nearest neighbours This has the effect of breaking shoals up, or merging them into larger shoals

to influence a group

Only a small proportion of informed individuals needed

Control of polygyny in Imported Red Fire Ants Monogyne form:

Only one queen Heavy Fat reserves Form new nests on their own

Proximate questions

Ontogeny=how behavior developed Mechanism=study genetics that control behavior

Solitary animals may collect cues from conspecifics - e.g. rattlesnakes select ambush sites in areas with chemical cues from successful conspecifics

Or head down feeding cues Or social animals may use cues to locate conspecifics

Effects on intermediate host Conspicuousness

Orange spot - causes infected animals to be eaten more frequently May exploit sensitivity of fish = receiver bias

Experiment on humans exposed to 17Hz sine waves hidden in music - upsetting results!

Other mammals can go lower into infrasound (elephants below 15Hz) or higher in ultrasound (dogs up to 45KHz; bats up to 120KHz) Sensitivity to infrasound may explain evacuation of tsunami-hit areas by animals

'sonic' range

Our range of hearing is referred to as approx. 20Hz up to 20kHz.

Trophic Transmission

Parasites can enhance their likelihood of trophic transmission from intermediate to definitive host if they can: • Alter the behaviour of the intermediate host so that it is more likely to encounter the definitive host • Exploit the perceptory system of the definitive host so that it is more likely to detect the intermediate host

To maximise their own reproductive output

Parasites use host resources... ...so resource-expensive behaviours by the host may not be in the parasite's interest Divert resources to benefit parasites' fitness •Sterilisation: physiological, mechanical, incidental •Growth: gigantism - in long lasting infections only!

Different kinds of animal social aggregations part 1

Part of the reason that it's difficult to provide a universal definition of a social aggregation is that there are so many different kinds

Penguin chicks signalling to parents

Penguin chicks form crèches as chicks. Important for returning parents to recognise chicks in the melee IF parents CAN recognise chicks, then chicks HAVE to be able to recognise parents Chicks can also recognise siblings and neighbours Recognition via acoustic cues Learn call structures (takes a few days); the calls are unique to each individual and highly stereotypic Adelie penguin recognition occurs across several syllables; king penguins capable of single syllable recognition

Frequency distributions of escape trajectories of insects

Perfect randomness would lead to perfect unpredictability... Are these random? An interesting difference between ETs of most insects and of vertebrates is that the latter often peak at 120° differences - keep pred in visual field

Fireflies attract mates using light flashes.

Photuris firefly watches then mimics females of other species and eats arriving males

Ultimate questions

Phylogeny=what is ancestral history of this behavior, evolutionary Adaption=how does natural selection help this animal

Adaptation can be

Physiological Behavioral

Host countermeasures Can a host do anything to rid itself of parasites?

Physiological responses • Immune response • Fevers or chills Behavioural responses • Grooming • Allogrooming • Enlist the help of other species • Self-medication

Under which circumstances would one expect females to compete over males?

Polyandry: Females hold territory and mate with as many males as possible, males take care of offspring Males are pregnant, put sperm in pouch (sea horses)

How can the bees know where to go?

Positive feedback

Behavior controlled by a Mendelian gene

Prairie vole Microtus pinetorum Monogamous High levels of social interest Males contribute to care of young Strong expression of vasopresson V1a receptor in brains

Caraco & Wolf's 1975 study on lions

Predicts optimum of two lions, but even though 4 lions have lower food intake than 1, lion groups usually larger than this

Hearing

Pressure waves enter ears, vibrating ear drum and ultimately mechanically activate hair receptors embedded in the basilar membrane

Rapid locomotion

Prey animals adapted to move fast - think of evolution to unguligrade locomotion Experiment on lepidopterans found that fast flying species more likely to survive attack BUT there is a trade-off Fastest flying insects may have to devote up to half body mass for flight muscle ...and that has a reproductive cost

The predation sequence

Prey animals may mount defences at one or more stages in sequence Avoid detection...but if you can't, then avoid attack etc n.b. Which category a strategy falls into is debatable (after all, animals haven't evolved to fit categories!)

Examples of Animal Cues

Prey animals often provide cues to predators - obviously not intentional! - CO2 and bromodosis attract mosquitoes - Activity attracts visual predators ...and vice versa - mentioned Schreckstoff before - more on that later Elephant belly rumbles!

If detection and probability of predator attack

Prey may synchronise to swamp preds - eg turtles, cicadas and...bats

Many predators have eyes that are mainly located facing forwards in the head - degree of binocular overlap

Prey species have more laterally placed eyes which gives wider field of view but less overlap The ability to move eyes is relatively unusual

Unpredictable locomotion

Protean behaviour prevents predator from predicting direction that prey animal will take Erratic nature of this increases likelihood of escape

Female digger wasps dig vertical burrows for young

Provision these with insects 1st Sign stimulus is the nest site 1st FAP (fixed action patterns) is to lay cricket down & inspect 2nd SS is the cricket and its location 2nd FAP is to drag cricket into burrow Problem with FAP is sometimes not responsive to changes in the environment Stereotypical sequence of events demonstrates weaknesses of fixed action patterns

Tinbergen's four questions

Proximate questions Ultimate questions

Preventing attack

Pulse of sensory information can be used to startle receivers and induce change in their behaviour Deimatic displays startle predators causing hesitation Eye spots on butterfly wings - eye and face-like patterns prevent attack Experiments suggest - conspicuousness (=high contrast) essential rather than realism. Has to be 'surprising' Behavioural change and warning colouration can be combined, as in certain species of amphibians

Brood Parasites

Raising young is time consuming and energetically expensive! Cuckoos and cowbirds parasitise the brood care of many different bird species Intense competition between hosts and their parasites in terms of signalling and communication

Contaminants have a range of effects

Ranging from Union Carbide & dioxin to chronic problems

Infanticide by mothers

Rates of infanticides by mothers as a function of maternal age

Altruism

Receiver benefits, actor suffers cost

Animal appearance changes over time

Receivers detect cues relating to health and diet Many colour displays rely on obtaining caretenoids Female house finches prefer brighter, redder males Females benefit from their choice: Brighter males are better parents - bring more food to nestlings.

The sense of taste both promotes appetite for safe foods and immediate rejection of toxic ones.

Receptor detection thresholds lower for sour and bitter tastes than for salty and sweet ones! (Why?) Whole system biased towards detecting potential poisons Don't need to LEARN to avoid these 'foods'...

To facilitate recognition & maintain social ties

Recognition can often be achieved through cues rather than signals Signals: Lobster‟s special greeting... Dolphin signature whistles Whales

The anti-predator functions of grouping can be sorted into categories

Reduce encounter rate with predator Reduce success of predator

Why would an individual kill its sibling?

Relatedness

Revision: calculation of relatedness

Relatedness = probability of two alleles being identical by descent

· Why don't parents prevent siblicide?

Relatedness to offspring is equal

Victim of our own success

Relative to other primates, inter-birth interval in humans is short As a result, mothers often have multiple dependent children • In the absence of contraceptive methods, infanticide only option to secure survival of older offspring

Pursuit

Relies on speed and/or endurance or over distance - wolves, hunting dogs and...humans Sometimes referred to as persistence hunting Very effective but the trade-off here is aerobic muscle isn't good for fighting Wild dogs capture rate much better than most predators - but often lose their kills to bulkier carnivores

Ambush

Relies on stealth, crypsis and limited movement Not just visual crypsis - predators can change the way they smell - ever noticed how your dog rolls? Assassin bugs use a variety of tricks - disguised visually and chemically - use prey debris & sticky plant resin Success depends on patience and timing.

A stable social unit favours honest communication

Repeated interactions & individual recognition discourage cheating Vervet monkeys good study system to examine this Complex language - different calls for: • different predators •a rival group •and other items such as 'food'

Examined effects of acute low dosage exposure to 4NP on behaviour of fish in small groups

Response variables: — No significant effect of dose 1. Swimming speed 2. Response to 'predator' — Significant effect of dose 3. Aggression 4. NND 5. Competitive ability

How much of a prey animal does a predator have to eat in order to be considered a predator?

Rift Lake cichlids •Eye biters •Scale biters •Fin biters •Baby eaters

Trading off risks and rewards

Risk affects animals' decisions in lots of contexts... From foraging under risk To courting under risk (guppies in bright light) To their parental investment

What if the sexes have unqual reproductive success?

Rivers and Willard Hypothesis:

Retina has two types of light-sensitive receptors:

Rods (sensitive to low levels of light at all frequencies), Cones (sensitive to light at specific frequencies) Fewer receptors compared with some other senses - BUT means that brain does much more interpreting work than with the other senses. Slows it down - n.b. race starts This can be demonstrated by visual illusions...

The Doomsday Machine

Russians had installed a fail-safe Honest System Automatically activated and impossible to deactivate If US attacked there was no possibility of rescinding the system

Collective behaviours are governed by principle of

SELF-ORGANISATION

Following behaviour isn't just about copying the direction of travel

SOCIAL CONTAGION!

To maximise reproductive output

Selection for mechanisms that: • Make more resources available to the parasite • Curtail costly or risky behaviour by the host • Feed and/or protect parasitic young

Oskar Stöhr and Jack Yufe

Separated at birth and raised as Catholic Nazi in Germany and Jew in the Carribean Things in common: - Wife yelling - Storing rubber bands on wrist - Liked sweet liquors - Read magazines back to front - Dipped buttered toast in their coffee

Predator adaptations to outwit prey

Several species of predator use 'Machiavellian' intelligence to capture their prey Examples: •chimp teamwork against colobus •orcas overturning ice floes •fishing herons Dolphins use features of the environment to corral their prey Or even build traps....

Confounding variables

Sex • Size • Condition • Hunger • Vigilance • Confusion

Imprinting

Sexual imprinting Filial imprinting and habituation to humans - Whooping cranes: costumes and audio playback

Sign stimulus --> releasing mechanism --> fixed action pattern

Sign stimulus: critical portion of an overall stimulus (or releaser) Releasing mechanism: a neural pathway Fixed action pattern: the behavioural response

The habitat helps determine which channel of communication (sound, chemical, visual, etc.) a species uses

Signal typically relates to the ecology of the animal. For e.g. visual signals good in clear, bright, uncluttered environments

Signalling

Signalling is often considered to be active, or intentional, but perhaps not always entirely deliberate It's fairly easy to say what signalling is (an attempt by a source to communicate and affect the behaviour of a receiver) It's much harder to say what signalling ISN'T. Why?

The 'Hotshot' hypothesis

Signals can take many forms, from direct (phenotypic characteristics) to indirect (territory quality and resource holding potential)

As with touch, experience ↑ taste sense so food and wine tasters can enhance this sense.

Similarly, animals adapt to local conditions by varying representation of their taste receptors

Evolution of cooperation in animals. What does Strangelove tell us?

Simple and easy to understand Enforceable in public Can't pretend to be able to do this, must be carried out

Courtship behaviour and mate choice

Simple steps to success... Animals like to choose! Pigeons produce more eggs and more fertile eggs if allowed choice Mauritius kestrels paired in captivity are less successful than those with free choice in wild Pandas are MUCH more successful (BUT free mate choice may conflict with the goals of genetic management Rare animals often do not breed well in captivity Complex courtship rituals fundamental to pair bonding and mating success in many animals

Honest Signals - Why Not Lie?

Since signalling is about the signaller trying to manipulate the receiver for its own benefit... ...so why not just lie? A sender might gain by sending an inaccurate signal • in a territorial dispute, the signaller might bluff willingness to escalate • male competing for female attention might exaggerate his qualities This area is of major interest, not only to biologists but to economists and to psychologists.

Without any controls, deceit ↑ and signals would become meaningless and therefore valueless (corollary with adverts)

Since signals AREN'T meaningless, something must have maintained intrinsic honesty over evolutionary time

Tendency of animals to follow a leader into the jaws of death What happened?

Single focal fish followed a single replica leader on 18 of 20 occasions But groups of 8 behaved very differently.

Small and weak mothers vs large mothers

Small and weak mothers: don't produce males because it would be a waste of resources because he wont be successful Large mothers: produce males

• Changes snail behaviour:

Snails unable to perceive differences in light intensity Infected snails spend more time out of cover,increasing likelihood of encounter with birds

Self-medicating behaviours

Some birds incorporate plants with anti-parasitic properties into their nests • Sparrows use quinine-rich leaves of Krishnachura more frequently when malarial infection rates are high • In Mexico city, some birds incorporate cigarette butts into their nests • Nicotine kills ecto-parasites • Number of butts is negatively correlated with parasite density

Biosonar

Some consider consider biosonar to be a distinct additional sense but probably specialised hearing. The superstars of biosonar are insect catching bats and dolphins - evolved this ability independently Emit frequent, short ultrasound calls The bat's calls are focussed by structures on the head and are perfectly designed to bounce back from even the smallest of objects. The flies are moving in relation to the bat and so the echoes bouncing back from the calls are subject to a Doppler effect which shifts their frequencies upwards.

Similar diversity of adaptation at the chick stage.

Sometimes the parasite chicks show detailed mimicry of host young - down to colour of mouth (v. important signal for parent birds!) But common cuckoo chicks have much brighter, redder mouth - yet even otherwise discerning hosts don't reject (even when it grows to 6x them!) Expt using heterospecific cross-fostering shows hosts feed outsiders less So how does cuckoo chick prosper? Mimicry of begging calls of whole brood!

Parasitoids

Spends portion of development inside a host, typically consumes and/or kills host before emerging • Free-living life stage

Communal Defence

Sperm whales threatened by orcas are known to adopt Marguerite formation Injured/vulnerable individuals places at centre of formation; larger individuals located on outside

but for one animal stealth goes out of the window

Stoats first attract the attention and then immobilise their prey

Behavioral genetics

Study of: • Behaviour that is genetically variable • Evolution of behavior • Proportion of behavior that is genetically determined • Identifying genes influencing behavior at the molecular level

Touch esp important in nocturnal/fossorial animals

Such animals often devote large amount of brain to processing touch information and huge numbers of receptors in their noses and whiskers Star nosed mole - super sensitive nose! Nocturnal animals e.g. raccoon mainly use hands to locate food - have disproportionate receptor numbers and representation of front paws within the brain. Animals with enhanced sense of touch have ↑ pain sensitivity ∝ nociceptor numbers

Interesting additional line of defence used by Australian host species...

Superb fairy wren mothers teach chicks specific calls while in egg These may act as passwords later when the chicks hatch and begin begging... Wrens use auditory signals to overcome difficulty of distinguishing visual cues

Robotic Fish for Pollution Detection

Swarm of robotic fish to navigate ports autonomously Communicate with each other and a central hub Fitted with chemical sensors to monitor pollution Localise polluters

Signal Components

Tactical components - relate to clarity of transmission and reception Strategic components - concern benefits to signaller of providing a signal MECHANISM and FUNCTION

or in some other way, manipulate their prey

Tentacled snakes use feint attacks to manipulate escape responses of fish prey. Snake carefully gets into position then initiates fake attack with middle of body Triggers fish's Mauthner cells to elicit escape response in wrong direction— directly toward snake's mouth Exploits a prey response that is adaptive for the majority of its predators

Recognition by Chemical Cues

The MHC affects the chemical signature of many animals Allows recognition of kin - useful for determining whether to co-operate with or breed with! Babies can recognise their mothers at age 3 days if breastfed Mothers also recognise babies by smell Women especially good at a T-shirt test... Function of osculation?

Collective Decision-making

The ants have no information initially.

Prevent capture (of vulnerable young)

The broken wing display - avocet, killdeer, plover etc etc. Why do they do it? Getting something terrifying, like a Bagrus, to look after the kids Cordon sanitaire of adopted young in cichlids

Tinbergen's Four Questions

The cause question: The development question: The function question:

Honest and dishonest signals coexist

The costliness of signals can reinforce honesty but some level of deceit is expected to evolve Animals like advertisers push honesty to the limit! Dishonesty in many cases is only a short step away. Populations are in flux - dishonesty may spread. For signallers, a mixed signaling strategy may be best For receivers, paying attention to costly signals, and to multi-modal signals

BEHAVIOURAL EPIGENETICS

The environment can affect gene expression and in turn affects the development of behaviour (among other things). Rats' response to stress is affected by early life experience: more mothering = more confidence How? More stressed rats end up that way because of down-regulation of glucocorticoid receptors

Strategic components

The essence of communication is relationship between signaller and receiver

information transfer between individuals in a group

The individual animals respond to their nearest neighbours. Wave of information spreads through group Information speed typically > individuals

When attacked, sea hares release two chemicals: a purple ink and a sticky substance known as ‗opaline'

The ink contains amino acids and is highly attractive. The opaline deactivates the chemical senses of the attacker

Robofish!

The possibility of integrating a robotic animal into a group of real animals offers fantastic opportunities! But in both the robofish and this example, a single animal leads a group...and that can only happen in certain circumstances

egg-retrieving behaviour in geese

The sight of a displaced egg triggers retrieval behaviour in many bird species ...but this behaviour can be triggered by a variety of objects Geese prone to 'supernormal stimuli' (larger the object like a football, more frantic to get back into nest) Cuckoos & their hosts Male Buprestid beetles (hump beer bottles) and us (McDonalds specificly use certain amount of salt and fat, plastic surgery)

What happens if you manipulate the size of the zones?

The sizes of the zones are state dependent and species dependent •Highly social species more tolerance to high packing density •Hungry animals may enact a large zone of repulsion and small, or no zone of alignment - cease to act collectively •Fearful animals may enact a small zone of repulsion and large zone of alignment - intensely collective in their behaviour

Solitary individuals fitness level =

Theorised to push groups toward stable, or Sibley group size

Why can this be seen as parasitism?

There is always an optimal group size * Individual has more to gain from joining a group, than the group has to gain but letting an individual join

Caveat:

There is often no hard and fast distinction between the two

Detection of air-borne odours 1000 or so different receptors. How does it work?

These receptors send projections via the olfactory nerve to olfactory bulb (antennal lobe in insects). Most odours made up of a number of different chemical components - 'smell' is representation of complex pattern of different elements (think of perfume manufacture).

Aggregation and alignment

These simple rules enough to produce most collective behaviour we can observe

Individuals in the group seem to act in unison.

They turn together, they flow around obstacles, they move as one. Their coordination is amazing - as though some centralised controller dictates all movement

Predator adaptations

This can mean that they have to specialise Orcas and (sometimes) lions have different guilds Predators initially inexpert with novel prey ...but can adapt to exploit new resources when necessary e.g. great tits and pipistrelles

Detection of pheromones

This is an ancient sense - not consciously perceived. Evokes behavioural or hormonal changes in response to specific smells. Fewer receptors - about 100 different types The right smell evokes an immediate and subconscious emotional, sexual or hormonal reaction. Flehmen response in mammals - gets the pheromone to the vomeronasal system (and makes them look stupid) For some spp e.g. hamsters, pigs, male sexual response dependent on female pheromones for activation Female mice recognise pheromones of familiar mate. Smell of strange male & novel pheromones causes abortion In humans evidence for pheromone detection equivocal...

Vision

This is the sense that we are most reliant on! Light entering the eyes is focussed onto the retina by lens - focussing achieved by muscles that stretch lens.

In some cases, predators may be disproportionately attracted to groups...

This may be especially important for predators that use non-visual senses...

Bees often abandon a patch while there is still food left

Thus, a bee does not fill its crop to the maximum

Sexual attraction in sticklebacks

Tinbergen experimented using different male shape and colour configurations to determine what females were responding to Found that females respond to red underside (not whole male), shape of fish didn't matter So the male's red belly is the sign stimulus.

Tactical components

To make sure the message gets across, effective animal signals typically employ: - Conspicuousness - Stereotypy - Redundancy

Complex animal communication

Topic of enormous interest... ...BUT, beset by anthropomorphism Tendency to view animal actions in terms of our conscious intentions Can communicate but not in a way that allows ability to describe experience of being Attempts to communicate historically almost always done wrong way around from Clever Hans onwards Tried to teach them to communicate like us More recent efforts better targeted

Behavioural changes in humansBehavioural changes in humans

Toxoplasmosis is gaining attention since it is widespread and implicated in human behavioural changes...

Many animals invest heavily in physical defences - some sacrifice mobility & rely on impregnable physical defences!

Trade-offs here as well: •Locomotion •Divert finite resources to defence Animals with more risk in medium and in short term invest more Crab-sympatric populations of gastropods thicker shells Others invest in ‗internalised' chemical defences or slime - tasting bad can cause a pred to give up! Hagfish go beyond just tasting bad But it's usually better to do this at an earlier stage of the predation sequence!

In many fish, social recognition based on chemical cues What do they recognise? What happens if they can't recognise?

Traditional ecotoxicological approach (LD50) formed basis of early legislation but this is a crude measure Sublethal effects of low dose exposure... There are many anthropogenic chemicals in the aquatic environment

How?

Trails established through pheromone Feedback

Quantitative inheritance of behavioral traits

Traits like alcoholism, tameness and IQ are controlled by many genes and strongly affected by the environment Require the techniques of quantitative genetic to analyze them

Highly flexible - animals can be trained that benign heterospecifics are dangerous and v.v.

Transmission can occur very rapidly and at different rates for different sensory modalities

Adult and Egg Stage

Transmission depends on host activity Low virulence Starling suffers little harm

Cystacanth stage

Transmission depends on ingestion of host High virulence As virulence increases, transmission increases

Trading off risks and rewards Tungara frog

Tungara frog (Physalaemus pustulosus) gives variable courtship call. If lots of competition, male can scale up call to make it more attractive with ‗chucks' ... but more attractive call makes male frog more vulnerable to predation. Trachops bat can more easily localize the frog when it gives the whine+chuck call So males balance need to attract females with need to stay alive! Male bushcrickets have a similar dilemma - top of vegetation is best for song, but worse for risk

Heritability of some human behaviour

Twin studies Monozygotic relatedness = Dizygotic relatedness = Should have the same environment If a character is completely heritable, monozygotic twins should be ? more alike than dizygotic twins

Working out the ESS

Two individuals meet at some resource worth 40 units Cost of injury in fight = -60 Cost for displaying = -10 • a is proportion of aggressors s is proportion of submissives (s = 1-a)

Reciprocal altruism

Two or more individuals exchange beneficial acts in return * Chimpanzees males distract the alpha from a couple mating, and when it's their turn to mate, it is reciprocated

Cheetahs

Typically a solitary hunter BUT can be found in small groups on occasions Usually brothers co-operate and hunt in teams

Reproduction

Typically, males advertise their quality and availability to females Females make a choice on the basis of these signals Male hammerhead bats compete for mates in leks -Signal using loud honking calls -Calls have large influence on mating success - 6% of the males obtaining 79% of matings Some of the most extraordinary signals relate to courtship! Animals that form lasting pair bonds often have complex bonding displays e.g. grebes

Sociality

Understanding social structures of animals broadly relevant - Management - Conservation - Production

BUT is the optimum stable?

Unless groups of optimal size can exclude newcomers, groups in nature will be larger than the optimum

Why signal?

Used to be assumed that signals evolved for the efficient transfer of information between sender and receiver BUT often conflict of interest between sender and receiver Led to idea that communication is an arms race between senders trying to manipulate receivers, and receivers second-guessing senders.

Starlings and sparrows

Usually few restriction to entry into their groups... ...BUT in some cases, newcomers have to join the bottom of the pecking order A large and diverse number of species form such groups

Pursuit hunters follow a trail, picking up prey cues

Usually through sight or smell of prey European catfish follow fish prey by tracking their mechanical wake shed during swimming - can follow wakes up to 10s old & 55 BL Harbour seals also do this when hunting at depth.

Parasite pathology:

Virulence of parasite depends on needs of parasite...

Female attraction pheromone...?

Volatile chemicals produced variably through the menstrual cycle Rated by males as being marvellous (but women have a better sense of smell...)

"Ultimate" Questions

WHY Function & Evolution Behavioural ecology

Case Histories

Washoe, a young chimp, reared like human children; taught American Sign Language (ASL) Washoe had a vocabulary of 132 signs Similarly, Nim Chimpsky learned 125 symbols...but not language All of these examples - human trainer and potential for the Clever Hans effect

Horsfield‟s hawk cuckoo additionally produces chicks with a bright yellow patch on underside of each wing!

Wave these to host parents (Tested this by painting them out!)

Your brain takes sensory information and uses this to construct a 'reality'

We have the idea that reality exists and that we experience it Truth is the other way around. Massive non-stop sensory info stream. Brain sifts to assemble reality Brain constructs 'internal model' But you have to LEARN to do this You can partly demonstrate this idea using optical illusions.

Effective courtship signals

What's the best way to signal to a mate (to anyone in fact)? A mix of signals is v. often the best approach For female toadfish there are at least three separate signals...

Local Resource Competition

When offspring of one sex compete directly with their parents

Local Enhancement

When offspring of one sex stay at home and assist the parents

Predator adaptations to predict prey

Where predators are able to predict abundance of prey in time and space, they can forage effectively by congregating there •Knot and crabs eggs •Grizzlies and salmon •Orcas and sealions •Tiger sharks and albatross

Aggression and submission

Where resources are limiting (food, nesting sites, mates), conflicts or contests may arise Aggressive acts are maladaptive Many encounters end only in display, without physical interaction

Overlapping goals

Where two animals have mostly the same goals, signals and communication are honest

The cause question:

Which stimuli illicit the behaviour pattern and what neurobiological, psychological or physiological mechanisms contribute or regulate this behaviour? Mechanism, how does the animal do it

Emergent Sensing of Complex Environments

While many wrongs works in principle, swarm intelligence may also emerge through basic interactions between individuals Works by the differential experience of individuals across groups Animals at the edge of gradient detect change and info spreads through group Performance increases with group size

Migration Training

White footed goose winters in SE Europe. Scheme to use barnacle geese for cultural transmission of new migration route to Netherlands

Dawn chorus

Why do birds always sing at dawn? (Not just birds - primates to cicadas) To get their message across efficiently! Microclimatic conditions - low local air turbulence, minimum attenuation Seldom a single simple reason for any complex behaviour! •Inefficient foraging - fewer inverts about •Low light makes visual signalling inefficient •Social feedback - cost of not calling high

Behavioural ecologists might therefore ask:

Why do some animals live in groups? Why do animals eat some types of food but not others? Why do some animals disperse? Why do some animals co-operate?

The function question:

Why does behaving in a particular way help the individual survive and reproduce?

innate behaviour is genetically determined and is largely based on stimulus response innate behaviours are triggered by a stimulus which must occur within the context of the animal's environment But not all members of a species display exactly the same innate behaviour

Why? Modal, rather than fixed, action pattern allows for variance (some flexibility)

Touch

Wilder Penfield 1st to map human somatosensory cortices - found some body regions disproportionately represented. More of brain devoted to touch stimuli from the genitals, lips, tongue hands, face and feet than the whole of the rest of the body. Areas of brain labile & use-dependent. In monkeys, preferential use of specific fingers can double their cortical representation. (Think about your thumbs!)

Finding food patches more efficiently in groups works via two main mechanisms:

With more individuals, groups can search an area more effectively The group acts as an 'information centre' and comprises the collective information of group members.

Taste

Works in conjunction with smell: 'flavour' is combination of activation of taste & smell receptors BUT sensitivity of smell receptors > taste receptors (e.g. colds and pegs!) 5 or possibly 6 different receptor types. Exact experience determined by pattern of activation across different receptors. Coolness, astringency, 'metallicness', 'spiciness', calcium detected by somatosensory system Receptors aggregated in groups of 30-100 in taste-buds embedded in surface of tongue (NOT distinct spatial locations!)

High-contrast markings e.g. bars, stripes proposed to serve for ―motion dazzle, make difficult for predators to accurately assess speed and direction moving prey.

Works opposite way to crypsis where animals conspicuous when they move, but protected when still As yet only correlational evidence and experimental data from human subjects on computers! BUT widespread use of striped bodily patterns might suggest role for motion dazzle

does size matter?

Yes · Quality of mother affects size of offspring · Size does not influence reproductive success of daughters · But: bigger males have higher reproductive success

Flocks, shoals, herds and....crowds

Zonal rules of interaction Local focus

At equilibrium, average payoff to aggressors=average payoff to submissives

a=0.75

hallmarks of animal cognition

ability to classify ability to recognize attributes of objects ability to count ability to remember the locations of objects in space ability to use language

Drafting

aerodynamics and hydrodynamics

the confusion effect only works when

all members of a group look the same

Feral fowl:

almost rape-like, but females can expel the sperm so they can't choose their sperm, tend to expel more submissive, weak males

recruits

also perform long and lively dances As a result, at the colony level only the best patches are exploited

Result:

appropriate allocation of foragers over nectar sources

Next question:

are there any within-colony feedback mechanisms that allows the colony to focus on the best pollen sources only?

Fovea centralis

area of central retina responsible for sharp central vision. Many birds have two fovea (we have one) increases sideways perception Finally - birds have high critical flicker fusion frequency. Can see things that would be a blur to us.

Obligate sociality

associate socially throughout lives

Facultative sociality

associate socially when needed

Given that 1 male is sufficient to inseminate multiple females, why do we find equal sex ratios most of the time?

assume all eggs are fertilized (males are never rare). Each female gains a fixed number of offspring, n, irrespective of sex ratio. However, the expected gains per male are the total progeny divided by the number of males (hence not independent of sex ratio)

Hamilton's rule:

b/c > 1/r

Asynchronous hatching

benefits parents

Appearance of a predator means

birds have to spend more time scanning - so have to feed in larger flocks to satisfy food intake

As group size increases

birds spend more time fighting and less time scanning

Again, not only visual mimicry -

can be done with sound cues too - burrowing owls pretend to be predators!

Marginal value theorem

can be used for many behavioural decisions

Cooperation

can emerge in an iterated Prisoner's Dilemma because players consider the future. If they know they will have to meet the player again, they may prefer R over P. If they will never meet the player again they should prefer to defect

Signalling

can help prey animals to avoid being attacked - ‗pursuit deterence' Famous example is of stotting in Thomson's gazelles but it's not only one! Pursuit-deterrent signals have been reported for a wide variety of taxa: •fish (Godin and Davis, 1995) •lizards (Cooper et al., 2004) •ungulates (Caro, 1995) •rabbits (Holley 1993) •primates (Zuberbuhler et al. 1997) •rodents (Shelley & Blumstein 2005) •birds (Murphy, 2006, 2007) ...and probably in many others, if we look!

Parent-offspring conflict results from

changes in the costs and benefits of parental care and asymmetries in relationship

Ethology

chiefly concerned with the mechanisms of behaviour FIXED action patterns / behaviours The development of FLEXIBLE behaviours The production and detection of cues and stimuli which are important to these

Intrabrood conflict

conflict over division of resources within current brood

Interbrood conflict:

conflict over investment in current versus future offspring

If one individual stands out

critical in driving the formation and maintenance of phenotypically assorted groups

public information

cues can communicate quality can then be used strategically to maximise foraging benefits

Other costs:

decreased ability to move, escape, or forage Long tail feathers of male birds serve as sexual ornaments And impair their ability to fly e.g. male Widowbirds in central Africa. The "signal" & handicap is the long tail.

Habituation

describes the reduction in response to a repeated stimulus Extensively studied in sea hares Observed throughout the animal kingdom - seals and different Orca guilds; humans and food Sensitisation is the opposite, an increase in response with repeated stimulus e.g. pain response in animals, dripping tap

Learned behaviour:

develops as the animal grows and gathers experience.

Sociality

different things to different people To some, 'sociality' refers specifically to animals which form societies To others...everything is in some senses 'social' By some definitions, virtually all animals live in a social context

Males compete in 2 ways

direct and indirect

Any foraging animal influences and is influenced by other foragers, even if they don't directly interact in time or in space

direct competition depletion of resources Avoidance local enhancement

Departure order explained by social relationships in macaques & baboons

dispersed leadership in birds and fish Others, like buffalo may be more egalitarian...

Predators have two main strategies

do I go to the prey, or I do I wait for them to come to me? Ambush or pursuit Phenotype gives clues as to which

As temp increases, or when there's more food,

dominants can afford to spend more time evicting subordinates

Many animals communicate at a frequency we can't detect

e.g. mice Some birds have phenomenal hearing - owls especially

Some species have different capacities

echolocation (or biosonar as it is now called), electroception, direction guidance using sun compasses, celestial maps and detection of electromagnetic fields.

Batesian mimicry -

edible or palatable species resemble an inedible species Success is frequency-dependent

return phase:

faster when nectar is of high quality

Offspring resemble

fathers more than mothers

Indirect competition:

female choice (intersexual selection) Males display in order to attract females

To increase reproductive success:

females provided with high quality food o Fed females significantly heavier o Fed females higher reproductive success § need more females to lead to population growth

Evolutionary Stable Strategy (ESS)

for parents to produce an equal sex ratio, provided that matings are random

Finding a mate

for some sessile marine animals, like barnacles, aggregation enables breeding.

•Behaviour of small components linked to

functioning of dynamic group-level properties

Basic rules of interaction are enough to

generate amazing responses to stimuli...

· Sneaker or parasitic males:

guaranteed sperm competition

Genetics of alcoholism

h2 0.3-0.4 (some studies 0-60%) Adoption studies 18% of adoptees from alcoholic parents develop alcoholism 5% in control adoptees

Acoustic adaptation

habitat structures influence bird songs is one major reason why birdsong sounds different in different parts of the world...

Rivers and Willard Hypothesis:

if the parent possesses a heritable trait that increases the reproductive success of one sex, it should bias the sex ratio towards that sex o The amount of investment in offspring to make them able to even breed

But ambush/pursuit is false dichotomy

in fact this is a continuum...

social behaviour

in the context of animal social aggregations - here, social animals are those that live in groups

The Westermarck effect

inbreeding avoidance recognition - based on MHC-genotype recognition

Predator success rate typically drop when the group size of their prey

increases

Risk therefore decreases as group size

increases

When confronted by a large group of animals, predators appear to become

indecisive and the split second hesitation allows prey to escape

Control is DECENTRALISED

individuals have no global plan (or even awareness)

Semiochemicals

info for animals

Local focus

interact with just a few near neighbours

Investment sex ratio:

investment in males and females

Vasopresson V1a

is expressed in the dopamine reward pathway Makes prairie voles feel good when cuddling mate

Optimal group size

is that at which individuals maximise time spent feeding

Social organisation

is the manifestation of social recognition

Behavioural ecology

is the study of how animals interact with their environment, and the 'survival value' of behaviours any given behaviour is ultimately beneficial - otherwise it would be eradicated

Should you go out to look for food patches...or let someone else do it?

it depends... Spice finches were taught to open lids and were producers. Other birds had to wait to scrounge

Operant conditioning (instrumental learning)

learning in which an animal is rewarded or punished for performing a behaviour OC is the mechanism by which an organism learns to associate its own behaviour with a result Examples: Rats in a Skinner Box press levers and receive food; circus animals etc Superstition= lucky pair of socks, rewarded if wear them More examples: cats rubbing themselves against owner's legs. Humans repeatedly pressing crossing buttons

Imprinting

learning that occurs only during a critical period. Process is genetically determined, but the particular object to be imprinted on is learned Filial imprinting Sexual imprinting The Westermarck Effect (reverse sexual imprinting)

Longer trip time =

less pheromone/time

A further benefit to group living is an adjustment in each group member's time budget = more foraging!

linked to AVOIDING PREDATION!

Group level patterns/properties EMERGE from

local interactions

Positive feedback:

longer and more 'livelier' dances attract more dance followers and thus recruits

Pheromone evaporates =

longer route, disregarded eventually

Sensory acuity

mainly associated with # of receptors dedicated to stimulus NOT how sensitive specific sensory receptors are Not all sensory cues are equal! Generally where a particular sensory modality is of greatest relevance more receptors will be employed and correspondingly more of the brain devoted. Can often deduce the ecology of species by observing sensory apparatus and brain

Direct competition:

male-male competition (intrasexual selection) Males compete (often fight) with each other over direct access to females or territory

Fisher condition:

males cannot, on average, reproduce faster than females if the adult sex ratio is even · Thus: both sexes better off staying together and caring for young · So, why doesn't this happen most of the time?

Facultative--->Tendency to associate with conspecifics--->Obligate

many animal species may move along this line over their lives

Cost (C)

measured in terms of decreased production of additional offspring by the parent

Benefit (B)

measured in terms of increased survival by the offspring receiving care

Waggle phase:

more of them when nectar is of high quality

Casual (mechanistic) and functional explanations

need to know HOW and WHY

No risk trials

no matter how small the difference in quality, HQ always chosen

The term 'leadership' implies centralised control /hierarchy

not always the case

Numerical sex ratio:

numbers of males and females

· Highest rate of extra-pair paternity

o 76% of young not sired by the female's mate o Females visit other males' territories o Prior to visiting males, females used song to choose their male

Supernormal stimuli

o Birds go for bigger egg because it's a superstimuli, more likely to look after

"foster parents"

o Birds have huge throats and foster parents stuff food in o Offspring manipulate parents into feeding more and more

· Brown bears

o Canada: males are heavily hunted; cub survival low o USA: no hunting; cub survival high § Disappearance of cubs shortens the mother's time to next conception. § Hence, males increase their fitness by killing cubs after take-over

Sperm competition

o Male-male competition after mating

Begging signals

o Parents respond to begging signals

Classical conditioning

occurs where animals learn an association between two stimuli CC is the mechanism by which an animal comes to associate events in its environment with consequences or objects with stimuli More specifically, it occurs where a conditioned stimulus comes to signal the occurrence of a second unconditioned stimulus After repeated pairing of the CS with the US, animal starts to behave in the same way towards the conditioned stimulus as it does towards the unconditioned stimulus Example: Pavlov's dogs.

Siblicide in boobies (Blue-footed booby)

older chick does not always expel sibling, much nicer

Long-term food shortage:

older chick expels younger sibling

Short-term food shortage:

older chick reduces food intake

Risky trials

only when HQ is 5 times better, HQ is always chosen

Brood parasitism

organisms that rely on others to raise their young.

Resemblance between child and father affects

paternal investment And the T-shirt test for odour similarity

Inclusive fitness =

personal fitness + fitness gained by reproductive success of relatives

five primary senses divided into two

physical contact between environment and the individual (touch and taste) remote detection (smell, hearing and sight).

women are 4 times more likely to

point out resemblances to the father

example of group selection

populations apparently regulate their size * Regulation of population size prevents extinction of the group * If there are competing groups, those that can regulate population size will out-compete unregulated populations.

Rule to calculate relatedness

r = (½)^n * n is the number of steps from the individual through all common ancestors back to the other individual being considered.

example of both Local Resource Competition and Local Enhancement

resources scarce: female biased sex ratio as females disperse (reduces competition) resources abundant: male biased sex ratio as males increase resource availability (local enhancement)

Collective behaviour

result from social interactions among individuals

· Stepfathers more likely to kill:

risk of a pre-school age child being killed by its adult carers is 40-100 times greater for stepchildren

Group defence

seen in dolphin pods and by kittiwakes mobbing predatory skuas, but fairly rare. The strange case of mussel self-defence

fixed action patterns occur in response to

sign stimulus or releaser

to recap

signals need to be clear and unambiguous, especially when the need to communicate is urgent, for example to appease an aggressor

Larger groups need

smaller proportion of informed individuals to reach a collective decision !

sensory ecology

study of how organisms acquire, process& respond to info from environment. Organisms and their sensory systems evolved so as to maximize the animal's fitness in the face of natural stimuli The world as we experience it is different from the world as it IS. Anthropomorphic subjectivity - even scientists!

Social cues

tell a watching animal when a group member has located food

Dilution of risk

the 'safety in numbers' argument Dilution relies on 'picky preds' - not great for krill...or is it?

Innate behaviour:

the animal is born able to perform. Sometimes referred to as 'instinctive'.

Behavioural ecology often concerns itself with benefits and costs

the economics of animal behaviour - the assumption that benefits > costs

animal's predation risk proportional to

the size of it's domain of danger

The success or failure of leadership is to an extent dependent on

the social status of the initiating individual.

counter strategy:

they pick out and preferentially attack less vigilant individuals

direction of sound is computed using

time difference for it reaching each ear (also shadowing effect of the head reducing the intensity of sound reaching ear screened by it.)

Critical element in any predator attack is

timing

Communication:

transmission of information from one individual to another Animals constantly send and receive information

Mullerian mimicry

two or more unpalatable species converge to look similar = gain great benefit 'speaking common language' e.g. wasps and bees

Musk ox also adopt a group defence

weapons facing outwards

What traits would this select for in males?

§ Ability to kill other sperm § Testes size § Higher motility § Larger sperm

Humans

· "beautiful parents have more daughters" · Polygnous society o In lower social economic standing, more breastfeeding in males o More important to have stronger male in higher social standing, because those in lower class don't have that much of a chance anyways o Milk fat increases in male offspring into higher SES

Multiparental families

· 'Partible paternity' · Growing fetus is nourished by semen · Every male ('father') takes responsibility

European Startling

· Added weights to tail feathers of males or females of breeding pairs · Determined change in amount of care provided to young

Why it is good to be helpful (if you are a male)

· Ask heterosexual women to rate the sexiness of men · Information provided on level of altruism

In many fish species males have alternative mating tactics

· Bourgeois males monopolise one or more females: no or low chance of sperm competition

Hamilton and Zuk Parasite hypothesis

· Bright plumage, complexity of songs etc indicator of lack of parasites · Females select for healthy males

Can't they simply resist males?

· But females often explicitly seek males o They receive benefits like § Upgrading: seek mating with males better than their social partner (superb fairy wrens) § Direct benefits like nuptial gifts (Adelié penguins)

Why it is good to be faithful (if you are a female)

· Compared 22 species of socially monogamous song birds · In species in which females are more faithful, males invest more in incubation

Sexual selection and mate selection

· Competition amongst males high, females choose the best males · Linne described 2 speicies of duck · According to Darwin's theory of sexual selection, the male ornament's sole purpose is to attract females: '[the secondary sexual character] depends on the advantage which certain individuals have over other individuals of the same sex and species, in exclusive relation to reproduction.' o Evolved for sole purpose of making individuals more attractive for attracting mates

Bell miners

· Cooperative breeders · Males are philopatric and help · Aggressive and competitive defenders of territories · Food sources build up with tenure (years) · Harmful to environment and trees so they overexploit resources and need to relocate · Produce more females because they disperse and don't help protect territory and compete with the parents · After 2 years, males are higher to mate with the higher females

Cryptic female choice

· Female is in charge!

Parasitoids

· Female lays eggs in host · Eggs develop in host · Last larvae emerge and pupate · Males emerge first and wait for females to mate with

Maximum number of children

· Female: 69 (in 27 pregnancies) · Male: 342 daughters and 525 sons

Fisher's runaway selection or the 'sexy sons hypothesis'

· Females prefer males with 'long tails' · Tail length in males and preference for long tails in females are in linkage disequilibrium · This selects for even longer tails in males and stronger preference for longer tails in females · Tails have evolved to such length that they are costly to the males that have them

'The Female Argument'

· Females should be the caregiving sex because the costs of producing ova exceed those of sperm. Hence, by not deserting offspring, females avoid wasting investment already made.

Six related sex changes in fish

· In many species of fish size matter · Small males have low reproductive success · Better off starting life as a female · Once bigger, turn into a male

Infanticide by males

· In species in which males hold territories that contain females, incoming (new) males regularly kill dependent young · The deadliest form of male-female conflict!

Concorde Fallacy

· Joint venture between Britain and France •Very costly plane to produce •Suffered major marketing problems •Could not possibly make any money for anyone •Yet, Britain and France kept investing because of past investments Past investment alone is irrelevant to decisions about the future

Trivers and Willard and the Kakapo

· Large, flightless parrot · native to NZ · Extremely long-lived · Reproduces every 3-4 years · Threatened with extinction o 82 individuals (22 females) relocated to predator free island o Reproductive success low

Adelié penguins

· Live in cold places · Require stones for nest · Will mate with males that bring stones

Unequal sex ratios

· Local Mate Competition · Example: when brothers compete amongst themselves for matings

Cryptic male choice

· Males adjust their ejaculation size depending on the attractiveness of their mate · Found in: Insects Crustaceans Fish Birds Mammals

Intrasexual selection with female choice: leks

· Males display together; females check them out

Intrasexual selection: harems

· Males fight over access to females or resources females need

Seed beetles

· Males have genital spines that damage females · The longer the spines, the more harm done to the female · Length of genital spines positively correlated to fertilisation success

The problem with being male

· Males have higher variation wrt reproductive success (previous lecture) · This variation is not random: certain males have traits that make them better mates · Thus, may be better to invest more in mating than in care · But at some stage, finding a mate may become very hard · It then becomes better to invest more in caring for offspring · As with selection for stable sex ratio (lecture on sex ratios), frequency dependence will shift levels of care

Superb fairy wrens

· Males hold territories and sing at dawn · Son is an honest signal of male quality · Lesser males move close towards better male's territory while singing · Highest rate of extra-pair paternity

Blackbirds

· Males' beaks range from yellow to orange · Females prefer males with orange beaks o Orange beak means immune system works better

Many males (mainly in insects) have special devices to remove sperm from the female prior to mating

· Mate guarding (e.g. damselflies) · Anti-aphrodisiac (e.g. fruit flies)

Who cares?

· Maternal care · Paternal care · Biparental care · Alloparental care

What if you are not sure offspring is yours?

· Most females mate multiply · Internal fertilisation: males will never be sure · Paternity uncertainty will reduce selection on male care

Conflict between parents over the amount of care to give

· Offspring need x amount of resources to reach maturity · Mother provides y amount of resources · Father then needs to provide x-y=z resources (assuming y<x) · The higher y (z), the higher the costs to the mother (father)

Honey bees

· One colony produces approximately 1 new queen per reproductive season · Same colony will produce hundreds of males (drones) · Numerical sex ratio is biased towards males, but investment sex ratio is biased towards females

Why do females mate more than once?

· One male provides sufficient sperm o Sperm limitation isn't a problem

Forms of care

· Preparation of the physical rearing environment (eg nest, territory) · Defence of offspring · Provisioning

Social rank affects female's condition

· Red deer on the Isle of Rhum · Mothers with high social rank produce more males · Males born to dominant females have higher reproductive success o Reproductive success of males is more influenced by maternal dominance rank than that of females. As a result, dominant females produce more males

Partial genetic incompatibility

· Sex ratio adjustment depending on color morph of male · Gouldian Finches (color polymorphism) o Mortality of daughters is higher if breeding occurs between different colors § More males formed then

Fundamental difference between the two hypotheses?

· Sexy son: tail or any trait not costly initially · Handicap: tail or any trait has to be costly to male

Seychelles warbler

· Single egg per year · Males disperse · Females help · High-quality territories: 1 or 2 helpers increase fitness of parents (local enhancement) · Low-quality territories: decreased fitness because reduced resources (resource competition) · More than 2 helpers also reduces fitness

Feral fowl

· Size of comb genetically and phenotypically correlated to number and mass of egg o Thus, females with large combs are more attractive · Offered dominant and subordinate males a choice between female with large and small comb · Females were fitted with a 'chastity belt' · Ejaculates collected

What if you are not big enough...

· Sneakers (fish, frogs, snakes) · Look and hang out with females and dominant males will not realize that they are actually males · Or can start life as a female (fish) until big enough to compete with other males

Implications of multiple mating by females

· Sperm competition · Cryptic female choice

What is the optimal sex ratio?

· Sufficient males to ensure that all females are inseminated · Complete waste of energy to make males if all females are able to impregnate by one male

Zahavi's handicap principle: Good Genes Hypothesis

· Tail length is linked to the male's fitness: the longer the tail, the more costly the tail and thus the more fit its bearer · Only males that are strong enough can survive to adulthood despite their handicap · By comparing the tails of males, females compare the relative fitness of the males · Females prefer males with the longest tails because they are the most fit

Fig Wasps

· The fig needs the wasp to pollinate to ovulate · The wasp lay eggs in the figs · Can choose the sex ratio because self mating haploid=male, diploid=female

The mating mind

· The human brain has evolved to be large and costly and this has happened quickly (in evolutionary terms). o Problems with birth due to big head · For a long time there didn't seem to be any survival benefits to having a large brain despite the costs. · No other animal has evolved language, humor, creativity. · Human males have been selected to be witty, clever and creative through sexual selection. · This has selected for large brains. · Females also need brains large enough to appreciate the wit etc. · Positive feedback results. · Selection stronger on males than on females; hence large variance among males because of linked mental disorders.

Can select for male traits that are harmful to the female:

· Traumatic insemination (bean weevils, seed beetles, bed bugs)

Deer mice

· Two species; one polyandrous, one monogamous · Sperm of polyandrous species recognise related sperm and form sperm trains · Sperm trains increase sperm motility

'The Male Argument'

· When females care a little more (because their eggs are larger), more males will be looking for females than vice versa · Thus, males should compete more and thus have less time to care

Harassment by fathers in birds

· When son leaves territory for its own, father goes and harasses son to make him return to original territory and help protect with him · More likely to return if younger because their success rate is lower if on own

Robert Axlerod's Prisoner's Dilemma

• Axelrod invited game theory strategists to submit computer programs that implemented their favourite strategy. 35 programs submitted, none were superior to tit-for-tat. • The tit-for-tat program starts with cooperation and then immediately does what the other player does. It avoids the sucker's payoff but rewards cooperation.

So...what does Kait's project tell us?

• Bees seem unable to determine protein content of pollen • Yet, pollen differ enormously in protein content • High protein important for bees

Why young should be cute

• Being sufficiently cute is the first step towards a pivotal commitment: protecting and feeding the immature • Human beings have a general instinct to take care of newborns, be it of the same or of another species

two possibilities among many:

• Bold individuals cannot afford to be risk-averse • Bold individuals ‗aware' of capabilities

Costs of group living

• Competition for resources • Increased risk of parasitism or disease • Increased opportunities for reproductive interference or suppression

The Tit-for-Tat strategy

• Computer simulation suggests that the greatest payoff comes from a tit-for-tat strategy: Cooperate on first move, then do what partner does

Group structures

• Different positions in a group bring different pay-offs - not all members have the same costs and benefits. • The safest place to be is often in the centre of the group, out of harm's way... • But central individuals get less food, so... • Cyclical changing of positions according to motivation

Game theory

• Emerged from strategic studies What is best defense for opposing force • Attempts to understand the best strategies for interactions with other parties • Adapted by evolutionary theorists and economists

Insulin-like Growth Factor (IGF)

• Example of imprinted genes • Pattern of expression depends on which parent transmitted the genes • Parent-of-origin conflict Haig · IGF-II: insulin-related polypeptide; plays key role in extracting resources from mother during pregnancy

Behavioural genetics Objectives

• Give an examples of animal or human behaviour with a strong quantitative genetic component and another influenced by simple Mendelian inheritance.

Feedback mechanisms

• Individual bee can determine quality of nectar source she is foraging at • Does not compare different sites • Feedback from receiver bees

Parasite-induced reduction in intermediate host's ability to detect predators

• Infected Gammarus no longer avoid predators • Unable to detect chemical cues, or unable to respond to them

The bases of this:

• Interacting individuals • Variation - information held by group members, random fluctuation • Amplification • Positive feedback • Negative feedback

Take home message

• It is relatively easy to predict, based on theory, how animals should behave • Whether the animals actually can behave in the predicted way is a different matter • It is thus important not to stop at theoretical predictions but to go out and test them

Why is nature often characterized by cooperation?

• Kin selection Individuals are likely to cooperate with kin (others) • Reciprocity theory If individuals have to repeatedly interact with each other, then they can increase their fitness by cooperation, avoiding P, the punishment for mutual defection.

What is going on?

• Most likely bees cannot determine protein because it is covered by a membrane • Plants make pollen smell irresistible to bees

What about pollen?

• Pollen is the bees' source of protein • Protein essential for brood rearing and for the queen to lay eggs • Nurse workers ingest pollen and convert it into brood food which is fed to larvae

• UV is as damaging for fish as it is for us, but reef fishes make their own sunblock

• Recent research has revealed that many reef fishes have the ability to see in the UV spectrum • This is especially prevalent in the larvae since the scattering of shortwave light can silhouette small prey items • UV may function as a 'secret' communication channel

Receiver-bias mechanisms

• Ritualization of protosignals focuses on characteristics of the sender • Sensory exploitation hypothesis: the receiver has a preexisting preference for a particular signal - Features of the receiver's nervous system makes it more responsive to a particular form of stimulus • Sender takes advantage of receiver's preexisting sensory biases when new signals are evolving.

Evolved strategies to maximise parasite's likelihood of transmission

• Some parasites have free-living stages that seek out the definite host e.g. Strongyloides stercoralis, Schistosoma mansoni (both enter straight through skin at follicle) & ectoparasites like mosquitoes • Some manipulate the actions of their hosts to get to where they need to be • And others rely on trophic transmission

Acoustic adaptation hypothesis

• Sounds attenuate and degrade differently in different environments - Songs are more attenuated and degraded in dense foliage - Lower frequencies less distorted in dense foliage • In habitats with complex vegetation structure - Songs should have low frequencies, narrow bandwidths - Whistles and long notes • In open habitat (i.e. grasslands) - Songs should have high frequencies and broad bandwidths - Trills and short notes

Individual decision-making

• Starlings fly from their nest to a feeding site • Food is collected to feed chicks • The feeding site is placed at different distances from the nest

The Prisoner's Dilemma

• Two felons rob a bank • Placed in separate cells • If both stay silent both get a minor charge (Reward for cooperation, R=3 for each) • If both confess, both get convicted (Punishment for defection, R=1 for each) • If one confesses and one stays silent, the silent cooperator goes to jail (Sucker's payoff R=0), the blabber (does not cooperate) gets a lesser charge (Temptation to defect R=5)

Signal detectability depends on interaction between:

• Type and quality of signal • Receiver sensory system • Transmission environment These three factors interact in determining the signalling strategies of species and populations

Single encounters

• What should you do when think your partner will defect? • What should you do when you think your partner will cooperate? • Conclude that? • What happens if you both defect? Hence the dilemma

The group as information centre

• When food is abundant but ephemeral, why not share information? - Fruit - Carcasses - Swarming insects

Costs and Benefits

• When one parent is not sufficient, both parents need to provide care • Each parent would like to minimise care at the expense of the other parent • When one parent dies or deserts, remaining partner may be forced to abandon eggs or young•

· IGF-II

• When paternal allele is experimentally inactivated: offspring 60% of normal size • When maternal allele is inactivated: no effect on offspring size

why?

•Animal have to reconcile these local interactions with goal- oriented behaviour •They have to be proactive & interact with environment! Find food, shelter, safety •The animals have to make collective decisions about where to go, and when to go •Self- organised animal groups often extremely effective at this

Collective decisions

•Apparently complex collective behaviour derived from local interactions between individuals.

Lots of examples - kin selection promotes cooperative signalling

•Bee waggle dance •Alarm calls in Beldings ground squirrels •Begging in chicks Begging CAN lead to conflict BUT parents respond because own fitness depends on offspring survival Parents provide food to chicks that beg most vigorously BUT excessive begging can make chicks obvious to predators

Best way to get message across is to be clear:

•Conspicuousness •Stereotypy •Redundancy

Uncorrelated landscape

•Consumed all food sources in a patch •Less exploration, more exploitation

Body chemistry is altered by:

•Disease (detector dogs) •Emotional state •Diet (like the Dutch in Japan!) Habitat and diet cues play a major role in social organisation of animals including insects and fish - a bit like 'smaccents'

Physiological / Autonomic responses

•Displays may originate from autonomic functions e.g. Skin of turkey, jungle fowl, and bateleur flush and swell during stress because of vasodilation These changes now part of signalling during courtship & agonistic encounters •Modifications of the respiratory system produce sound and visual signals e.g. Male frigate bird's throat pouch inflates to an enormous size and brilliant color to attract females •Piloerection (erection of feathers and hair) traps heat. Also a part of aggressive and appeasement displays e.g. If all the hair is erect on tamarins : aggression/attack; if only tail hair is erected: fear/flee

Nonylphenol

•Found in surfactants - ubiquitous •Toxic at high levels •At lower concentrations - endocrine disrupter •Lipophilic

Access can be gained to novel foraging opportunities by group-living animals two main mechanisms:

•Gaining access to defended resources - overcoming the attentions of a territory- holder •Co-operative hunting - strategic predators!

Predators can co-operate

•Honey guide and honey badger •Moray and grouper •Bottlenose dolphins co-operate with human fishermen in various parts of world

Seen under a UV filter, the colour of some familiar fish changes totally

•It turns out that bright yellow is a great colour for camouflage! •It also reveals hitherto unseen markings.

Some hunters specialise at certain times of day when conditions suit their sensory capabilities e.g. reef predators in twilight

•Light decreases from 10k lux to 0.0001 lux •Cone dominated light-adapted eyes of diurnal prey fish not well suited •Crepuscular activity - only 5% of the 24 hour cycle, 85% of all hunting •Predators strike upward at silhouettes

Correlated landscape

•Moves on when LQ food encountered •Less exploitation, more exploration IF food of low quality is found

Parasites and host behaviour

•Parasites influence host appearance and behaviour in a number of ways - •But when is this genuine parasite manipulation? •Sick animals behave differently - Side effects/pathology simplest explanation - may or may not benefit the parasite -Example Crassiphiala trematode infests fish. Large numbers cause reduction in shoaling, increase likelihood of being eaten by bird •Direct manipulation is more than just being an energetic drain on host...or is it? •Hard to say where 'indirect' ends and 'direct' begins

Animals also have to balance response to risk:

•Risk-prone behaviour can obviously be costly •Risk-averse behaviour can be costly too

A defence against inaccurate decisions or informational cascades?

•The group of 8 followed only when a quorum of 2 was reached •Amplification of incorrect decisions is often a potential problem in social groups •BUT a quorum rule reduces the probability of errors being amplified throughout a group. •While we can experimentally dupe fish into making errors, quorum responses generally improve the accuracy of decision-making.

If the only decision-rule that every individual uses is 'copy my neighbour' then what happens? •So how do grouping animals filter out bad information?

•They apply a simple decision rule, called a 'quorum rule'. They only follow when a threshold number of leaders has been exceeded - they don't typically follow single individuals.

Exploration versus Exploitation

•Time spend within a patch increases with patch quality •Search pattern depends on food distribution •area-restricted search when food is abundant Flexible foraging behaviour, depending on experience

Natural Forage Dances

•Two observation hives - University and Warrah •Film returning natural forager dances •Collect pollen from dancing and non-dancing foragers

Comparative approach has been criticised for various reason:

•correlation does not imply causation •inability to consider alternative explanations

Receptors detect:

•salty •sweet (sugars) •sour (acids) •bitter (alkaloids) •umami (glutamate receptors, i.e. detects monosodium glutamate and meat-like tastes).