exam 3 FINAL behavioral ecology info

ESS if value of resource < cost of fighting

ESS is a mixture of HAWKS AND DOVES all doves: higher payoff (+25) than all hawks (-25) -but a mutant hawk in a population of doves will always have the highest payoff (+50) all hawks: payoff = (-25) -not always beneficial to fight every time -a mutant dove that always retreats from a hawk has a higher payoff (0) the rarer strategy will always have the higher success frequency-dependent selection: the fitness of a phenotype or genotype depends on the phenotype/genotype composition of a given population

sequential assessment model

Enquist and Leimer individuals assess their opponent's fighting abilities multiple times -only sampling fighting ability once might lead to mistaken conclusions sampling multiple times leads to more accurate estimation of fighting ability level of aggression initially begins low aggression level increases if individuals have similar fighting abilities the more evenly matched, the longer the fight should be and the more phases it will go through fights with multiple behaviors for assessment will go through the same phases in the same order for all fights

ESS if value of resource > cost of fighting

HAWK all doves: higher payoff (+50) than all hawks (+25) -BUT a mutant hawk in a population of doves will always have the highest payoff (+100) and greater reproductive success all hawks: payoff = (+25) -a mutant dove that always retreats from a hawk still has a lower payoff (0) -never beneficial to be a dove unless everyone else is a dove ESS (evolutionarily stable) = HAWK if value of resource > cost of fighting animals should try and fight for highly values resources

ideal free distribution vs ideal despotic distribution

IFD predicts: 1. how individuals should settle into habitats 2. the equilibrium frequency of individuals in different patches density dependent decline in habitat quality- more individuals= decreased habitat quality IDD predicts: 1. how individuals settle into habitats 2. the equilibrium frequency of individuals in different patches competition dependent decline in habitat quality- as density increases, weak competitors suffer a steeper decline in habitat quality than stronger competitors

handicap principle

Zahavi 1975 in order for a signal to be reliable it must be costly because only high quality individuals can afford the cost

territory and learning

a common assumption of territoriality is that animals can asses characteristics of an area BUT these models do not explicitly consider how learning affects: -the establishment of a territory -the maintenance of a territory establishment: -anolis aeneus is a good species model to study territory establishment because they form territories early in life -most work on territoriality centered on distribution of food -Judy stamps 1986 wanted to test for food distribution but never got any results showing food was impacting territory selection -found temperature and predation pressure best identify suitable territories for species Stamps noticed juveniles watch other lizards of the same species -she hypothesized juveniles may determine territory quality as a result of interactions with conspecifics -if another individual deemed a territory as safe for itself, the territory is probably safe for the juvenile as well -used enclosures of similar habitat one with adult and one empty and allowed a juvenile to observe -juvenile chose closure that had had adult in it much more quickly than the control

where to eat: marginal value theorem

a model used to predict how long an animal should remain in the same patch (Charnov 1976) predictions made by model: 1. Gains of staying in the patch will decrease as patch is depleted by forager 2. forager should stay in patch until they can do better elsewhere (travel costs included) 3. forager should leave when expected gain from the current patch goes below expected gain of a new patch -at the point that gives the greatest gain or food intake per unit time -the point where the line indicating travel time to the next patch touches gain curve 4. the greater the distance between patches, the longer a forger should stay in a patch 5. should stay in a higher quality patch longer than in a lower quality patch

optimal foraging theory

a set of mathematical models used to predict various aspects of animal foraging behavior within a given set of constraints (MacArthur and Pianka 1966) weighs the costs and benefits to predict what an animal should do to maximize its fitness four models: -what food items should a forager eat? -how long should a forager stay in a certain food patch? -how is foraging affected when certain nutrient requirements are in place? -how does variance in food supply affect a forager's decision about what food types to eat?

byproduct mutualism

a type of cooperation where an individual pays an immediate cost for not acting cooperatively, the immediate net benefit of cooperating > the benefit of not cooperating

ultimate reasons for aggression

access to mates territorial defense food defense protecting family members when should conspecifics escalate contests to fighting? -might depend on quality of the opponent -might depend on what others are doing -might depend on whether one individual values a resource more than the other

When to eat 2 prey types

according to OFT, prey 2 should only be taken with prey 1 if encounter rate of prey 1 drops below a certain threshold encounter rate of prey 2 is not important in decision about whether to take prey 2 or not krebs: tested OFT predictions in the lab using Great Tit -provided with 3 different-sized pieces of mealworm (different energy values) on moving conveyor bely -researchers controlled encounter rate for each prey item -found great tit did increase intake of smaller mealworm as encounter rate of larger mealworms decreased

Herbivore

an animal that eats only plant material

detritivores/decomposers

an animal that ingests dead material (detritus)

omnivore

animal that eats a combination of plant and animal material

Carnivore

animal that eats other animals

Aggression (agonistic behavior)

animals either send threatening signals and/or engage in physical combat common loons aggressively defend breeding territories -the best territories have small islands for nesting -reduces predation from snakes, raccoons -due to population decline, humans began setting out artificial nesting platforms Mager et al 2008 wanted to know if platforms increased aggression in loons -did a 3 year study -2002: no platforms on any lake -2003: platforms added to some lakes but not others (control) -2004: platforms were removed -measured reproductive success -observed # of times loons engaged in aggressive behavior on an escalating scale -recorded when intruder landing on lake, intruder approaching resident, social gatherings between intruders and residents, aggressive displays or chases, fighting in 2003 on platform territories there was: -an increased # of aggressive interactions and likelihood that contests will escalate -lower reproductive success -higher incidence of males being displaced (1 killed) -short term study

warning coloration

aposematism: using bright colors to warn predators that you are unpalatable or dangerous mullerian mimicry: multiple toxic/ threatening species have similar warning coloration to reinforce their warning signals to predators

approaching predators

approaching a potential predator may provide important info about the predator's motives and reduce mortality or attack very risky, usually only healthy adults approach approach movements towards a predator are interrupted with pauses or retreats also called: predator inspection, boldness, investigative behavior fitzgibbon (1994): studied function of approach behavior in Thomson's gazelles -approach behavior was more likely to occur in larger groups -cheetahs moved farther away in response to gazelle approach behavior as gazelle group size increased -approach behavior appears to reduce predation risk for the individual (helps with predators that use surprise attacks)

blending into the environment

avoiding detection may be the most efficient antipredator behavior crypsis/camouflage: avoiding detection by blending in with the background not necessarily behavioral, but behaviors can increase ability to blend in ex: sitting still on matching background can actively change color/texture to blend in with current background ex: many cephalopods (squid, octopus, cuttlefish) able to do this rapidly can build camouflaged structures ex: gerygone nests resemble a pile of leaves and debris that hang from trees being quiet -freezing behavior or reducing noise can allow prey to avoid being detected by a predator -predators sometimes eavesdrop on prey -listen for sounds that prey produce to find the, more easily -prey can also eavesdrop on predator sounds

bluffing

batesian mimicry: a harmless species imitate a toxic or threatening species to avoid being eaten often use visual signals could also use auditory or chemical

honest signals related to foraging

bee waggle dance discovered by Karl von Frisch female worker bee returns to colony and communicates to other workers where food source is located by shaking abdomen and moving in figure 8 pattern waggle dance provides 2 types of info: -the direction of food source in relation to the hive and sun -conveyed by the angle at which dance occurs in relation to ground -relative distance or energy required to reach food -conveyed by length of waggle -roughly 1 sec of waggle= 1 km of distance from hive

planning for the future

can animals plan and store up food for the future? western scrub jays cache food and remember cache locations, food type, time of cache, and who saw them caching the food Raby et al (2007) exposed hungry jays to a compartment with no food or a compartment with food that could not be cached -alternated which compartment they were exposed to for 6 training trials -after training, gave jays a food bowl with nuts that could be cached in cache trays in either compartment -jays more liekly to cache food in the "no food" compartment than in the "food" compartment in 2nd experiment, jays only exposed to peanuts in one compartment or dog kibble in the other -given food bowl next day containing either kibble of peanuts -more likely to cache kibble in peanut compartment and cache peanuts in kibble compartment

Other way to use MVT

can use MVT for optimal patch time for any situation where a resources is depleted over time and there are traveling costs (Parker and Stuart 1976) -how long should a male search for a female mate? ex: -yellow dung fly lay their eggs on fresh cow droppings -males wait on the droppings for females to arrive -after mating, a male needs to wait until egg laying to ensure his sperm is not displaced by a second male -how long should he copulate/wait before seeking out another female? how long should a parasite search for a host? -parasitoid wasps remain longer in patches with higher host densities (Tenhumber 2001) -parasitoid wasps reduce all host patches to the same level of profitability before leaving for the next patch (Wajnberg 2000) How long should a cheater remain in a patch to exploit cooperators? (Dugatkin and Wilson 1991)

honest signals related to foraging

cliff swallows nest colonially -produce "squeak" calls to alert conspecifics to a new food patch (ex: swarm of insects) (Brown et al 1991) -facilitates group foraging -benefits signaler because more foragers increase chances of tracking insect swarm juvenile common ravens often call when they find a large food source (parker et al 1994) -attracts juveniles to the food -together juveniles can overpower a larger, territorial male defending the food source juvenile ravens form roosts near newly discovered food sources -roosts tend to move as new food is discovered -individuals in a roost usually go in the same direction to the new food source -Marzlruff et al 1999 found: -ravens captured and taken to a new food source and then released were more likely to lead their group to that new food source the next morning -ravens captured and denied info about new prey locations, then released layer, were more likely to follow the group to the nest food source -unclear on how ravens know who to follow

animal signals

communication between animals occurs via the use of signals animal signals- an action or structure of a signaler that sends a message to a receiver types of signals used depends on environment and species -mammals, snakes often use odors -marine mammals use sounds -frogs, reptiles, birds use sounds, colors -fish use colors (shallow water) -insects, spiders use vibrations, odors

costs and benefits of territoriality

cost= red line benefit= green line the zone between the curves= territoriality is economically feasible arrowed line= optimal territory size when the benefits increase, so do the range of feasible territory sizes

costs vs benefits of migration

costs: weight loss must adapt to different environments vulnerable to habitat loss benefits: avoid inhospitable environments avoid higher predation avoid higher competition costs and benefits of migration for songbirds: reproductive fitness: -temperate resident: high= can produce more offspring if NO migration -migrant: moderate= migration reduces time to breed -tropical resident: low= fewer young per attempt, high predation adult survival: -temperate resident: low= must endure winter -migrant: moderate= successful migration allows better winter survival -tropical resident: high= always favorable environments

honest signals related to mating

deep calls in toads/frogs only made by larger individuals- accurately conveys body size to females brightness of bird plumage is indicator of body condition/parental care to potential mate antler size in the antlered fly correlates with body size antler size in red deer correlates with fighting ability, strength, and fertility

Territoriality

defined as the occupation and defense of a particular area defending territories can cost the owner: time, energy, physical injury/death territories can benefit their owners with exclusive access to: food, mates, refuge from predation

assumptions of the marginal value theorem

each patch type recognized instantaneously by forager travel time between patches in known by forager gain curve is smooth, continuous and decelerating over time -if travel time and gain curve are known, then optimal time to leave can be predicted tested by Cowie 1977 using Great Tits: - had great tits inside aviary with mealworms hidden in saw-dust filled plastic cups with lids -some lids easy to dislodge (short travel time) -some difficult to dislodge (long travel time) -as "travel time" increased, time in patch increased, as predicted

migration and navigation continued

earth's magnetic field -has evidence of influence in: birds, amphibians, reptiles, insect -pigeons with magnets attached lost orientation on cloudy days -loggerhead sea turtles migrate across the pacific ocean -Lohmann 1991 monitored hatchlings directionality -hatchlings swim in the opposite direction when the tank's magnetic field was reversed -Lohmann mimicked magnetic fields from different parts of the Earth's surface -when the NE edge of their habitat was simulated, they swam SW -when the SW edge of their habitat was simulated, the turtles swam NE

frugivory

eating mostly fruit

Folivore

eating mostly leaves

granivory

eating mostly seeds

xylophages

eating mostly wood

cost of signals

efficacy cost: cost of making the signal clear to receiver signaling requires some level of energy -ex: stotting behavior may be risk associated with signaling -ex: alarm calling to warn conspecifics of predators makes caller vulnerable to predation strategic cost: a signal that is more "expensive" than it has to be to convey honest info

what to eat: profitability

energy gained/handling time the greater the ratio (the more e and less h), the more profitable the prey item OFT model predicts that the most. profitable prey should NEVER be ignored even though a certain prey choice may provide less calories, it may be the better choice based on handling time ex: 15-spined sticklebacks prefer to eat crustacean prey based on their size -small fish eat smaller prey than large fish ex: pied wagtails -most profitable prey size was 7mm (calories/ seconds handling time) -wagtails choose this prey size regardless of availability relative to other prey sizes

assumptions of the model

energy intake from prey can be measured in some standard currency (ex: calories) foragers can't simultaneously handle one prey item and search for another prey are recognized instantly and accurately prey are encountered sequentially (not all at the same time) natural selection favors foragers that maximize their rate of energy intake

being quiet: gulf toadfish

ex: Remage-Healey et al (2006_ studied antipredatory behavior in gulf toadfish -gulf toadfish produce "boat-whistle" sound that dolphins (predator) listen for -dolphins produce various sounds while foraging, including "clicks" and low frequency "pops" -gulf toadfish hear best in low-frequency range -do toadfish respond to dolphin "pops" by reducing the boat-whistle sound they produce? -captured male toadfish during b reeding season and kept them individually in tanks -exposed them to one of four treatments of sound emitted underwater -low-frequency dolphin pops produced during foraging -both pops and whistles -control: sanpping sounds made by snapping shrimp recorded toadfish behavior before, during and after playback toadfish reduced calls by 50% when dolphin foraging pops played and at least 5 minutes after played, but not in other treatments males exposed to pops showed higher levels of cortisol in blood (stress hormone)

evolution of honest signals

for signaler: only beneficial to produce signals if they modify receiver's behavior to signaler's benefit for receiver: only beneficial to change behavior in response to signals, if receiver is actually benefitted signals will be honest when BOTH the signaler and receiver benefit

Learning and foraging

foraging innovations often seen in primates and birds the ingestion of a new food type or the use of new foraging technique ex: using tools to obtain food -Heron using lure -chimpanzees using sticks for termites Lefebvre 1997 reviewed examples of foraging innovations in birds -bird groups with the most foraging innovations also had the largest forebrain size -birds with larger brains also better at invading a new area -partly due to their high use of foraging innovations

search image

forming a representation of a prey item so it becomes easier to find over time (Tinbergen 1960) ex: in bobwhite quail, the probability of detecting prey increases with each successful prey capture may have evolved as a response to finding cryptic (hidden or ambiguous) prey helps animal filter out what is and isn't prey

Game theory models of aggression

game theory can be used to predict under what circumstances, fighting, fleeing, or just displaying instead of fighting is nest for an individual hawk-dove, war of attrition, sequential assessment all assume fighting imposes a cost all have variable representing the value of the resource being contested -can be easy or difficult to estimate -the value might differ for each individual in the contest

producing toxic or foul smelling substances

hoopoes produce foul smell from uropygial gland (preening gland) to keep predators out of nest cavities bombardier beetles spray predators with a highly noxious chemical -formed from a reaction between hydrogen peroxide and hydroquanines -chemicals react in reaction chamber inside beetle and shoot out at 100 C (boiling water level)!! skunks cuckoo chicks produce foul-smelling feces that appears to reduce predation -great-spotted cuckoo non evictor, raised alongside host -host usually can rear some of its young with the cuckoo, but female cuckoo often destroys some eggs -when predators of chicks were presented with food items smeared with cuckoo feces, they rejected food great-spotted cuckoos and carrion crow hosts -in years of low predation, crows had lower reproductive success when raising a cuckoo -in years of high predation, presence of foul-smelling cuckoo in nest reduced predation on parasitized nests -crows with a cuckoo had higher reproductive success than unparasitized crows

habitat choice

how an animal distributes itself (in space and time) in an environment based on habitat use resources that can contribute to habitat choice: mates prey/food refuge from predation ecologists have long suggested that animals distribute themselves in relation to the distribution of resources

Where to eat: patch model

how long should an animal remain in the same food patch or at one individual food item it is depleting (ex: a bee at a flower) costs of staying in a patch: -depletion of food in patch -prey items might begin more evasive actions cost of moving patches: -loss of energy from travel -potential predation during travel -lost time foraging

ideal free distribution (IFD) Model

ideal- assumes animals are aware of each patch's quality free- assumes animals are capable of moving unhindered between patches distribution- where animals exist within a landscape model suggests the number of animals that aggregate in various habitat patches is proportionate to the number of resources in each this model can be used to: 1. predict how individuals should settle into habitats 2. predict the equilibrium frequency of individuals in different patches r1/n1 = r2/n2 if you have 2 patches with unequal intrinsic values, the number of individuals in each patch will be unequal but will still reach equilibrium the purpose of this behavior is to minimize competition and maximize fitness between individuals milinski 1979: -6 stickleback fish in a tank -tank has 2 feeder on opposite ends (food= water flees) -distributed based on amount of food resources -follows matching rule Harper 1982 -tested free distribution model individually recognizable mallards ate the food -2 students threw food in a pond -not able to support IFD individual aggression leading to disproportionate amounts of food is better characterized by the ideal despotic distribution

hawk-dove antibourgeois game

if cost of fighting is very high and many vacant territories are available, it might pay to play Hawk-Dove antibourgeois game owner always vacates when an intruder approaches the previous owner finds another territory and causes that owner to vacate only found in the Mexican spider Burgess 1976

Risk-sensitive foraging

if food is more variable, there is a higher risk of doing well or doing badly risk sensitive optimal foraging models ask the question: how does variance of food sources affect patch choice? example: patch 1: always receive 8 food items every time patch 2: 50% chance of receiving 16 food items, 50% chance pf receiving 0 food items (on average still 8) -patch 2 is higher risk, higher variance in food intake/hour model predicts that animal's hunger state will determine which patch it chooses

Hawk dove bourgeois game

in game, a bourgeois is a territory owner and should always fight for his territory, but retreat when he is an intruder assumer bourgeois is territory owner half 1/2 time (hawk) and intruder 1/2 time (dove) when playing a hawk or dove, payoff is average of hawk/dove cells ESS = all individuals play BOURGEOIS bourgeois is never injured and fights never escalate= intruder always gives up payoff is always +25 studied in speckled wood butterflies (Davies 1978) -male territories consist of sunlit patches in a forest -short-lived -found individuals typically played the bourgeois role and avoided fights -who won in the past did not matter -only fought when both males entered unoccupied territory at same time

function of signals

increase inclusive fitness of signaler -getting food -warning relatives of danger -signaling to a predator to reduce chances of attack -getting a mate

conspecific cueing

individuals determine which territory to choose based on what others have chosen

audience effects

individuals involved in aggressive interactions change their behavior if they are watched by others studied in chimps (Slocombe and Zuberbuhler 2005) -chimps scream during aggressive interactions -those winning the fight produce "aggressor screams" while those losing the fight produce "victim screams" victim screams were longer and more intense if.... -aggressive encounter was more severe -audience was present -audience included at least one member with equal or higher rank to aggressor in this situation, higher ranking audience member often stopped fight

proximate reasons for aggression

individuals that choose to stay and fight have higher levels of testosterone individuals that choose to run away often have higher levels of cortisol serotonin has a variety of effects depending on species -in mammals: low levels often found in subordinates -leads to increased fighting -results varied depending in study in fish: high levels often found in subordinates -leads to reduced fighting in crustaceans: high levels often found in dominants -leads to increased fighting

dishonest signals: photuris firefly

male lightning bugs give specific flash pattern answered by flash pattern of female males fly to female to mate female of photuris firefly mimic flash pattern of male photinus firefly photinus males fly towards female photuris thinking it will get to mate but photuris female eats male as long as photuris is rare, photinus males should still always respond to flash pattern otherwise can't mate

feigning death

many insects and spiders will feign death when approached by predators adzuki bean beetles can either flu away from predators or feign death -time spent feigning death depended on flying ability (Ohno and Miyatake 2007) -better flyers feigned death a shorter period of time

origin and modifications of signals

many signals originate from simple movements by signalers that were informative to recipients selection has favored reactors who anticipated intended behaviors of signaler example 1: if dog always shows teeth before biting, selection would favor receivers who understand that teeth = about to bite selection also favors the signaler to bear teeth before biting so signaler can reduce aggressive interactions with receiver example 2: harmless snakes worldwide will rattle their tail in dry leaves when they feel threatened (sounds like rattle snakes) -evolved into a threat signal -rattlesnakes create sound when tail shakes, letting intruder know they intend to strike -selection favors this signal to reduce wasting venom on intruders and to reduce intruders being bitten

choosing safe habitats

many species create burrows/hiding places nest in tree cavities. on side of cliffs, under the ground, etc.

Hawk-Dove game

maynard smith and price used to study when individuals should decide to fight, or just display and retreat only 2 possible strategies in this game: HAWKS: always fight to win the resource (may injure opponent or could be injured) DOVES: only display (act aggressive), but then retreat if opponent continues escalating the aggression -never engage in serious fights, so never injured both strategies are not flexible= all or nothing 2 variations occur: value of resource > cost of injury value of resource < cost of injury if hawk meets hawk: we assume half of the time they win and half they pay injury cost if hawk meets dove: hawk always wins entire resource, dove always retreats if dove meets dove: neither suffer injury, but they split the resource (get 1/2 value)

animals that are satiated

more likely to be risk averse: forage in food patch that is more consistent

animals that are hungry

more likely to be risk prone: forage in more variable food patches

fleeing

most common response of a prey to predator is running for its life if a bird's nest is attacked by predator and chicks close to fledging, chicks will pre-fledge some tadpoles can hatch early to escape being eaten -use vibrations produced by snake as a cue to hatch out early

types of play: object play

object play: moving inanimate objects around in the environment -Heinrich 1999 studied raven play behavior -young ravens extremely playful, manipulating new objects they find -novel objects played with more often than familiar objects -edible objects played with more often than familiar inedible objects -object play might allow ravens (omnivores) to learn which objects are potential food sources -object play in cheetahs increased their rates of patting, grasping and biting live prey their mother had just released for them (Caro 1995) -object play could reduce stress for animals in captivity Pigface, a soft-shelled turtles, clawed at himself until given objects to play with

modeling habitat choice

other than resources, habitats can be chosen based in the likelihood of exposure to diseases one way to do this: produce your offspring in habitats that have low parasite levels disease-filled habitats: kiesecker and skelly 2000 -frog larvae and snails are hosts to a parasitic trematode worm -made 25 artificial ponds -5 treatments: 5 uninfected snails, 5 uninfected snails, 10 infected snails, 10 uninfected snails, no snails (control) results: controls were most favored -of the uninfected, frogs chose those with low snail densities

ritualization of signals

over time, signals will become modified to increase their effectiveness and clarity ritualization- signaler's movements become highly stereotyped, repetitive, and enhanced by evolution of bright colors, louder sounds, stronger smells, etc. reduces ambiguity of signaler's intention courtship displays indicate strength of bond copulation solicitation displays from females indicate readiness to copulate in females agonistic interactions -used to determine winners of contests for mates/territories/resources -usually begin with low level of aggression in order to "size up opponent" -if opponent does not give up, aggression level increases until their is a winner dog postures let receiver know signaler's state and intentions -play vs fighting -submissive vs aggressive/dominant

territory and learning- maintenance

owning a territory requires vigilance against predators and intruders maintaining a territory has costs and benefits satellites= intruders that do not own the territory but are tolerated by the owner pied wagtails systematically search territories and time their movements to ensure optimal benefit form their territory -wagtails defend riversides in the winter where insects wash up on the banks -insects are considered renewable in this case because more will continue to wash up -if a wagtail times their rounds, it can deplete the insects in one part of its territory, search other parts for food, and when it returns there will be more insects to eat Davies and Houston 1981: -pied wagtails sometimes chased off competitors and sometimes tolerated them -cost benefit model to predict when owners would allow satellites costs: -owner loses some foraging benefits benefits: -satellite doesn't know which areas have already been cropped for insects -owner gains satellite's assistance in territory defense results: when food availability was high, satellites were tolerated -when food availability is low, satellites were viewed as intruders and chased off byproduct mutualism territorial dynasties

migration

periodic movements to and from breeding/ feeding sites obligatory migration = occurs like clockwork seasonally/annually irruptive migration= occurs when environmental conditions are poor partial migration= occurs when only a portion of the population migrates, and the rest stays put -american robins -savannah elephant

play

play behavior involves movements that don't appear to serve an immediate survival function -practice fighting -chasing one another for no obvious reason -moving an object for no obvious reason -practicing hunting for prey that isn't there common in mammals, also found in some fish, amphibians, reptiles, birds, octopus play behavior is understudied -largely anecdotal, only recently examined experimentally -function of play is unclear, may be difficult to determine -difficult to measure and define behaviors might appear purposeless to humans because we may not understand the immediate benefit, benefit may occur later, or there may be multiple benefits we are unaware of

play markers

play can be similar to dangerous activities signals that indicate the desire to play rather than fight -pawing and play bow in dogs -vocalizations: chirping in rats, whistling in mongoose -distinctive smell -facial expression in lowland gorillas

types of play: social play

playing with others may lead to long-lasting social bonds -young male chimps play and form coalition bonds that they maintain as adults may help refine skills for fighting, hunting, mating allows individuals to self-assess their abilities against others of a similar age

foraging

searching for and consuming food

boy who cried "wolf!" ground squirrels

selection should favor receives can ignore dishonest signals hare and atkins 2001 wanted to know if individuals receiving inaccurate info from a signaler would eventually learn to ignore it juvenile richardson's ground squirrels exposed to 2 treatments: 1. heard recorded squirrel alarm call and saw a stuffed badger (predator) 2. heard recorded squirrel alarm call and saw no predator after 10 trials of hearing alarm call, squirrels in 2nd treatment were less likely to respond to the calls than those in the 1st treatment LEARNING

animal signals categories

self-reporting signals: signals a property of the signaler (positive or negative) ex: male sexually selected traits/displays ex: begging of offspring to indicate to parent they are hungry ex: aposematic coloring to deter predators other-reporting signals: signals an object or an organisms other than the signaler ex: alarm calls ex: location of food (honey bees)

farming/ growing food

several examples of animals that grow their own food or protect other species producing food sources leaf cutter ants farm fungi -use leaves they cut to create a fungus garden -ants protect fungi from predators/competitors -fungi break down cellulose in leaves for ant -ants eat fungus/feed to larva -ants that farm fungus have streptomyces bacteria growing on them -bacteria produce antibiotics -protects fungus garden from specific parasites -bacteria passed on to next generations of ants several examples of animals that grow their own food or protect other species producing food sources -some termites build large mounds where they grow mushrooms they consume -3200 species of ambrosia beetles grow fungus inside bark -damselfish grow algae in coral reefs -remove, but do not eat, unwanted material from algae gardens -protect algae from predators -type of algae grown depends on species/ locations

more examples of farming/growing food

several examples of animals that grow their own food or protect other species producing food sources some ants farm aphids -aphids feed on plant sap and excrete honeydew -ants milk aphids and eat honeydew -protect aphids from predators -lead them to leafy pastures bell miners farm psyllid insects -psyllids eat sap form leaves, producing sugary substances called lerps -bell miners are honeyeaters that eat lerps -bell miner groups aggressively defend psyllids from insect-eating birds -sometimes, actions of bell miners cause mass defoliation of tree patches

honest signals

signals that convey accurate info about you or the environment ex: producing alarm calls when predators are around ex: letting predators know you see them

distraction

some animals use distraction displays to escape predators killdeer parents distract predators from their young cephalopods squirt ink before escaping a predator -may reduce predator's visibility -may confuse/startle predator -ink may become a "pseudomorph" - appears like some other creature acanthephyra purpurea (shrimp) and fire shooter squid produce ink with glowing globs when escaping predators lizards perform tail autonomy (lose tail) -tail often squirms around after its detached

specific nutrients

some species require a specific nutrient in order to survive may alter their optimal foraging habitats nutrient quality often more important to herbivores -plants often lack essential nutrients (ex:sodium) ex: Belovsky (1978) looked at forging in moose -moose require lots of sodium and energy to survive -terrestrial leaves contain little sodium, but lots of energy -rumen (gut) is only so big -Belovsky predicted moose should spend 18% of time foraging on aquatic plants -observations closely matched predictions

warning sounds

some tiger moths are noxious to bats tiger moths produce sounds that cause bats to avoid them (Barber and Conner 2007) some edible tiger moths produce similar sounds and bats avoid them

fighting back

sometimes animals must make a choice: fight or flight many bird species will mob larger predators in groups -also works to deter brood parasites from nests -who is a threat is passed to new generations via cultural transmission -curio et al 1978 study on blackbirds

communicating to predators that they have been spotted

sometimes letting a predator know you see them, is effective at deterring them prevents an energetically costly chase from occurring for both prey and predator ex: tail flagging in deer may be a signal to both conspecifics and predators -some evidence that the fastest deer are more likely to tail flag and tail-flagging may deter predator attacks caro et al (2004): snorting in ungulates also deters predator attacks -may signal to predator the health and vigor of the signaler stotting in gazelles and antelopes when a predator is sighted to deter attacks -stotting = stiff-legged jumping with all 4 legs off ground -individuals do this with and without conspecifics present -cheetahs abandoned hunts of stotting gazelles more often than hunts of non-stotting gazelles

being quiet more examples

songbirds often stop singing if a hawk lands nearby bats emit echolocation pulses while hunting -in response moths reduce their activity Jones et al (2002) studied female greater wax moth response to bat echolocation calls -female moths perform wing-fanning behavior in response to male moth calls -wing fanning makes females easier to find for bats -male calls sound similar to bat echolocation calls -females reduced wing fanning behavior when exposed to bat echolocation calls, but not when exposed to male moth calls -also distinguished between bat "attack prey" pulses and bat "searching for prey" pulses

territorial dynasties

territory ownership os passed down through generations Florida scrub jays exhibit this behavior -starts with a monogamous pair of birds -at 2.5 years, a male offspring will expand the boundaries of the family territory ("budded" territory) -will continue with up to 6 helpers (results in a large territory) benefit: -increases family's total territory size -provides young male with his own smaller territory -create a form of inheritance costs: -conflict within families: -not common but can happen -young male may want to leave at a certain time but parents might want him to stay and help raise young

antipredator behavior

the selection pressure on prey to avoid being eaten is higher than the selection pressure on predators to capture prey prey are running for their lives, predators are only running for a meal= LIFE-DINNER PRINCIPLE (Dawkins 1979) 2 basic categories of antipredator detection: -those that help prey avoid detection -those that help prey survive once detected

communication

the transfer of info form a signaler to a receiver often used by signaler to modify receiver's behavior ex: chicks begging for food -intended receiver is parent -parent responds to chick begging by bringing more food for hungry chick ex: monarch butterflies signal to predators that they are toxic -predator should avoid eating monarchs

group size and foraging

typically increasing the number of individuals foraging in a group also increases the amount of food each forager receives each individual can spend less time being vigilant (watching for predators) and more time foraging more individuals able to flush put more prey -Mittlebach (1984) found that bluegills caught more prey as foraging group size increased cooperative hunting increases success rate of catching prey -can take prey larger than yourself -can defend kill from other predators/ scavengers foraging in a group can provide public information

social foraging and public information

use the actions of others to provide updated information about the environment's condition solitary foragers can acquire info by: -visiting a patch earlier -keeping track of time spent in patch, how much they have eaten group foragers can acquire info by watching success of others -starling foragers with another starling left empty food patches earlier than starlings foraging alone (Templeton and Giraldeau 1996)

migration and navigation

using cues to assess where you are in relation to where you are going types of cues: landmarks/topography sun compass star compass magnetic compass sun compass -clock-shifted the butterflies 6 hours -tricks animals into thinking it's the opposite season -kept a control group of non-shifted butterflies -control butterflies headed south like normal -clock-shifted butterflies flew west, which is where they would fly if they were using the sun as a compass -morrison and frost 2002 put butterflies in a flight simulator. showed when the butterfly was flying and what direction. -confirmed sun as a compass the star compass -emlen 1975 -majority of perching birds migrate at night to avoid predation -indigo bunting is a good model species as they are nocturnally migratory and migrate 2000 miles/year -placed birds in funnel-shaped cages, ink pad on bottom -ink prints showed bird orientation and when it took off for flight -flew north in the spring, south in the fall -took off randomly when sky was cloudy -repeated experiment in planetarium and altered the stars -the removal of single stars did not affect bird orientation, but found they rely on stellar formations

types of play: locomotor play

vertical jumping, which may involve arobatic moves (twisting, flipping, etc.) running, climbing, etc. studied in rodents, primates, and ungulates 2 hypotheses for function: -could provide exercise, training for motor skills used later in life -could provide animals with a better lay of the land

honest signals to warn relatives of predators

vervet monkeys produce multiple types of alarm calls that vary depending on the type of threat -cough calls = eagle --other vervets respond by looking up or hiding in bushes -barking call = leopard --other vervets respind by going up in a tree -chutter call = snake -other vervets repsond by standing tall and scanning the grass belding's ground squirrels give both aerial and terrestrial predator alarm calls downy woodpeckers produce alarm calls in response to seeing an aerial predators BUT (Sullivan 1985) -if foraging alone: 0/46 times -if foraging in flock without other woodpeckers: 0/23 times -if foraging with members of the same sex: 0/6 times -if foraging with member4 of the opposite sex: 7/9 times -MATE INVESTMENT

predation and foraging trade offs

vigilance: looking for predators can't be vigilant and forage or do other activities at the same time foraging in larger groups allows some individuals to be vigilant while others able to forage the choice to eat a food item where it was found vs taking it to a safe place depends on predation risk -distance from refuge -food item size

fleeing: flight initiation distance

what factors affect flight initiation distance? (Stankowich and Blumstein 2005) - the distance a predator can approach before a prey flees distance from refuge (den, hiding spot, territory, etc.) -prey flee sooner the farther they are from refuge animals involved in other activities (mating, foraging, fighting) were slower to flee from predators previous experience with a predator causes a prey to flee more quickly -animals flee form humans at a greater distance during hunting season compared to other times of the year perception of risk affects prey's decision to flee -predators size, speed, directness of approach can alter a preys perception of risk -a prey's morphological features can affect perception of risk -animals with armor (shells, spines, etc.) are less likely to flee at a given distance than animals that don't have armor -camouflaged animals less likely to flee

bystander effects

when individuals observe a fight between 2 other individuals and learn something about fighting ability of future opponents Earley and Dugatkin (2005) studied bystander and winner/loser effects in green swordtail fish -placed a bystander fish in a separate tank while two other fish were pitted against one another -later, pitted bystander against either the winner or loser of the previous fight treatment 1: bystander had one-way mirror and allowed to view the fight treatment 2: bystander had opaque partition and unable to view the fight fish that could see the fight were less likely to initiate or escalate a fight with the winner

evolution of dishonest signals

when only signaler benefits, signals may be dishonest dishonest signals: used to deceive/manipulate the receiver and only benefit the signaler -take advantage of a typically beneficial response be receiver -nestling birds beg to indicate their hunger level -parent responds by feeding nestling -not beneficial response if nestling is brood parasite -typically parents feed their own young, may be better to always feed despite some parasitism selection should favor receivers that ignore dishonest signals -reed warbler nestlings typically fledge at 11 days -common cuckoo spend > 15 days in nest -reed warblers sometimes decrease feeding rates to cuckoo chicks after 11 days and some abandoned chicks after 14 days (Grim et al. 2003) -cuckoo have evolved begging calls that mimic the sound of an entire reed warbler brood

what to eat: prey choice

which prey items should an animal target? which size/age of prey should it target? according to the OFT, each prey item has... -an energy value (e): how much energy it provides the animal that is eating it -an encounter rate (λ): how often the animal eating it encounters it -handling time (h): how much time it takes for an animal to kill and/or ingest the prey

dishonest signals using alarm calls

white-winged shrike-tanager inSA forages with other bird species shrikes perch in canopy, waiting for other birds to flush insects so they can capture insects for themselves shrikes also watch for predators and will alarm call if predators seen other birds hide when shrike alarm calls sometimes shrike produces alarm calls when no predator is present, particularly if shrike and another bird are chasing some insect if alarm call is given during a chase, competitor abandons and shrike gets insect if you ignore alarm call and a predator is present you could die if you heed a false alarm, you only lose one meal evolutionary stable strategy some males use false alarm calls to increase their reproductive success -male barn swallows sometimes give false alarm calls to disrupt EPCs between their females and another male -male topi antelopes give false alarm calls to distract females so they can mate with them sometimes male vervet monkeys give false alarm calls when they encounter a new troop (Cheney and Seyfarth 1990) -new troop takes off for cover -male caller avoids potential aggression from group -male callers tend to be less dominant, single

winner and loser effects

winner effects: winners tend to win again -winning increases testosterone -higher testosterone increases aggressiveness and probability of winning loser effects: losers tend to lose again -losing increases production of stress hormone (cortisol) -often suppresses production of testosterone blue-footed boobies Drummond and Canales 1998: looked at winner and loser effects in blue-footed booby siblicidal chicks allowed some individuals to experience dominance over siblings or subordination took experienced dominant individuals and pitted them against larger inexperienced individuals -experienced dominants were more aggressive took experienced subordinates and pitted them against smaller inexperienced individuals -experienced subordinates were less aggressive

War of attrition model

winner is determined by waiting different lengths of time or displaying long enough to gain a resource (ex:mate) assumptions of war of attrition: individuals can choose to display aggressively or wait for any duration of time display behavior or waiting is costly-- the longer the display, the more energy expended there are no clear cues such as size, territory possession, etc., that contestants can use to settle a contest ex: dungflies -females lay eggs in dung, males find dung early and wait for female to arrive -female will mate with the first male she encounters and he will guard her from other males -females prefer to lay on fresh dung because crust forms on older dung -how long should he wait for females? -how long should he guard her before finding a new dung patch/female to mate with? male's strategy is frequency dependent: depends on what other males do -if most males stay for a short time in dung patch, males who stay longer will have increases reproductive success -if an individual male always waits the same time at a dung patch, competitors could opt for a time that would always beat that male -ESS would be to choose random wait times so competitors would not know your strategy -studies of dung flies demonstrate "stay times" are random

risk sensitive foraging example

yellow-eyed juncos offered choice between 2 feeding sites one consistent (5 mealworms) one variable (0 or 10 mealworms, but mean of 5) 1 hour starvation- chose consistent food source 4 hour starvation- chose variable food source why switch from risk-averse to risk prone? after 1 hour: -consistent food patch: enough food to meet energy requirements variable food patch: 50% chance of getting more than enough, 50% chance of not getting enough after 4 hours: -consistent food patch: no chance of providing enough food -variable food patch: 50% chance of providing enough food, 50% chance of not providing enough food

migratory resltessness

zugunruhe= a restlessness or an inner stirring to more during the onset of migratory activity Berthold 1990 -compared zugunruhe activity between birds in the lab and in the wild -found strong correlation in onset behavior between the groups -suggests the timing or departure for migration is inherited Pulido et al 2001 -tested many generations of 1 species of bird (German Blackcaps) -measured migratory restlessness