Animal Behavior Final

antipredator behavior

any behavior that reduces chance/severity of predation

juvenile crabs and their habitat choice based on coloration

Researchers analyzed which habitats crabs chose based on whether predators were present. All crabs chose camouflaged environments when fish present

corticosterone & tree lizards

lizards with cort patches hid for longer and were less latent to first predator response

evasive actions

scares or startles predators

swallowtail butterflies startle

when predator detetced, start flapping wings. butterflies did this 75% of the time, and 80% of the time, it worked. only 3 butterflies killed!

tiger moths avoiding bats

moths hear echolocation, use erratic flight pattern, freefall, and produce their own pulses.

trade-offs

giving up/ modifying one behavior for another, risk of predation is a cost on other behaviors

elk scanning for wolves

vigilance vs. foraging: scanning vs. feeding rates

males and females spent more time foraging compared to females with calves, had to be more vigilant

fear of predation in song sparrows

song sparrows in predator playback group produced significantly less offspring and eggs, and the eggs that were produced failed to hatch at a much higher rate

dilution effect

larger group, less chance that a given individual gets taken in a predation event

selfish herd

each animal tries to get to center of the group, less chance of being predated in the center

“many eyes” group size effect

as group size increases, vigilance per animal decreases

deterrence

when prey actively engage the predator

harrassing or mobbing

california ground squirrels and deterrence

protect pups by kicking dirt and sand at snakes

they also raise temperature in their tail so attack is directed at it

dispersal

one-way, often short-distance, movement of an animal away from a particular site

why disperse?

1) avoid crowded conditions or competition for resources

2) avoid inbreeding

3) maximize reproductive success

goshawk natal dispersal

when researches added food to some nests, dispersal decreased

meadow vole dispersal

researchers placed sets of siblings or non-siblings in patches, males dispersed most often and did so more in sibling groups

dragonfly breeding dispersal (territory selection)

artificial sticks placed as mating sites. treatment males not allowed to make at these sites. all control males who could mate came back to the site. only 50% of those who couldnt mate came back

migration

two-way, variable-distance, seasonal movement of an animal

why migrate?

to avoid harsh seasonal conditions or take advantage of seasonal resources elsewhere

migration evolution

began with breeding dispersal, after some returned “home”; if migrants have higher fitness, all will migrate in time. it evolves and then unevolves

red-spotted newt partial migration

any individual may or may not migrate; those who do need new skin

females migrated more than males, especially in high density

how do animals migrate?

orientation & navigation

types of orientation

• physical landmarks

• sun compass

• star compass

• geomagnetic compass

monarch butterflies migration

all eastern monarchs migrate to Mexico, takes generations. use sun compass to migrate. researchers slowly changed sun cycles, butterflies flew accordingly

loggerhead sea turtles migration

bicoordinate navigation- use 2 coordinates to ID location

sea turtles given varying magnetic cues to see how they reoriented

habitat selection

animals choose where to live based on resource availability and potential for competition di

ideal free distribution and predictions

opitmality model, low density: all animals choose high quality habitat A

medium density: most choose A and some choose B

high density: some choose each habitat, all have low fitness

Predictions:

1) animals settle in proportion to population density

2) all animals will have equal fitness

guppy habitat selection

researchers placed food in bars in tank and manipulated how much was in each bar. guppies followed linear pattern of food to individuals, but it took time to assess

cuckoo habitat selection

eat gypsy moth larva which periodically have outbreaks. cuckoo abundance in these areas spike, and they travel far to get there

conspecific attraction

when animals choose habitats near competitors on purpose

alee effect

low population densities, more conspecifcs mean more mates and vigilance against predators

conspecific cueing

prescence of conspecifics indicates quality of habitat

desert clickers habitat choice

choose mating habitat

american redstart male territory choice

new adult males use playback male songs to decide where to settle. yearlings and returning adults no big difference

territories

areas defended for exclusive use of resources, some animals. costly to defend. depends on individual condition and environmental factors

home ranges

areas used repeatedly, all animals

game theory

mathematical model used to determine when to fight

sequential assessment model

game where individuals keep fighting as long as the benefits exceed costs of continuing

predicts 1) low cost behaviors used early in fights 2) evenly matched contests last longest

territorial contests in fiddler crabs

low intensity behaviors used first in fights; even matches lasted the longest

supports sequential assessment

challenge hypothesis

territory contests raise testosterone, which commonly turns on aggression

winner effect in california mice

males that win a contest have elevated T and tend to be more aggressive afterward

sexual selection

form of natural selection that acts on traits affecting reproduction

primary sexual characteristics

organs and body systems for producing and delivering gametes

secondary sexual characteristics

indirectly affect reproduction through mate competition or attraction

eyespots on peacock’s tail

males with more eyespots mated more

anisogamy

one sex (males) produce many small, mobile gametes; the other produces few, large, immobile gametes

isogamy

having similarly sized gametes, ancestral

Bateman (1948) fruit fly mating & hypothesis

96% of females had young, only 79% of males did

male reproductive success limited by # of mates he can acquire, while female limited by number and quality of eggs she can produce

parental investment theory

where one sex invests more into offspring, members of the other sex will compete to mate with the former

operational sex ratio

ratio if males to females willing to mate at a given time

red deer antlers

costly weapon for mate competition, overall trend: higher antler mass, higher breeding success

african widowbird tails

ornament for mating

tails are costly

females chose to nest with males with elongated tails

pipefish mating roles & stripes

males accept eggs from females and raise them, role-reversed species

researchers tested if males preferred more or less striped females

striped females get more and faster dances as well as more mating overall

sensory bias

traits tap into preexisting bias for color or patterns or movement, how sexual selection can evolve

guppies & orange spots

when predation high, little preference and less spots. when predation low, more spots amd higher preference

why do sexually selected traits exist?

1) direct benefits: choosy sex chooses a partner who offers something

2) indirect benefits/fisherian runaway: choosy sex has preference for something and it becomes linked

3) indirect benefits/good genes: choosy sex chooses partner who offers higher quality genes

4) indirect benefits/ Hamilton-zuk: choosy sex chooses partner with costly ornament

firefly male flashes and spermatophores

males with longer flashes had bigger spermatophores, more nutrition for egg

european tree frog calling

males call to attract females (dangerous- Handicap principle)

offspring of more attractive males were bigger

field cricket calling

males make energetically costly ticks

females preferred long ticks, these males had faster encapsulation rates

black-winged damselfly

removes competitors sperm when mating

green tree frog satellites

both females and satellite males had preference for lower frequency calls, satellites know what females like

pumpkinseed sunfish sneakers

sneakers place sperm near mating parentals, parentals defend young

sneakers are young and not that successful

blue-headed wrasse sex change

only 1 male, but that male was once the largest female. when it dies the largest females will become male

mating systems

sexual partners and social associations used by a species during breeding

mating system varitation in reed warblers

high food environments: promiscuity, little paternal care

low-food environments: monogamy and more paternal care

fathers help when they need to

monogamy in poison frogs

1- males bring 1-2 tadpoles to small pools and females feed them eggs

2- males bring several tadpols to larger pools where they can eat on their own

in small pools, both species need females

female defense polygyny in horses

stallions defend females from other males, multiple horse bands use same areas

resource defense polygyny in red-winged blackbirds & study

males attract 0-2 females and defend all of their nests. his care is spread thinner with more nests

after being removed from their territory, females chose to be the second one in a high quality territory rather than only one in bad one

polygyny threshold hypothesis

females should choose polygyny when resource benefits outweigh costs of sharing

male dominance polygyny in great snipe

leks: groups of males displaying near each other, arranged by dominance

do not defend resources or females, just display

when hotshot males removed, other males left

male dominance polygyny in peafowl

males close to a food source get most matings, regardless of status

polyandry in shorebirds

females evolved to lay more eggs than 1 male can incubate

defends several males on her territory and lays egg for each one

genetic promiscuity

occurs when males can increase offspring number and females can increase offspring quality

social monogamy w/ genetic promiscuity in juncos

?

parental care

any activities that incease survival of young

females feed young more in black-throated blue warblers

females are usually sure that their young are theirs, but males less sure

paternity certainty=more care

females brought more food

bluegill sunfish males adjust care, sneakers

each egg is more important to male fitness

tested for effects of sneakers on male care

fathers reduce care when they arent sure it was fertilized by themselves

prolcactin and maternal care in rats

tested for effects of prolactin by blocking receptors and adding differing amounts

females injected showed greater maternal care

parent-offspring conflict

parents want to provide equal care for both current and future offspring, but current offspring want as much care as they can get

extra pup in galapagos fur seals

extra pups do well in good years, or when food is abundant, and poorly in bad years

interspecific brood parasites

lay their eggs in nests belonging to other species

partial parasites are most successful

cuckoo brood parasites

cannot lay their own nests, mimic egg size and shape of hosts

sociality

living in groups with social relationships. varies in timing and group composition

prey breadth in coyotes

followed packs of different sizes to see if it impacted prey type

larger packs, larger prey; sociality increases breadth

food & group size in red colobus and red-tailed guenon monkeys

food availability should limit group size

researchers looked at tree density and compared it w size - true!

dominane hierarchy

organized system w dominant and subordinate members, reduce aggression

social queuing for dominance in clownfish

dominant female, her mate, subordinate males

females get replaced by their mates

followed fish, each male moved up in cue each time

social queuing

each subordinant moves up w age

altruism

behavior that helps another at a cost to the helper

inclusive fitness

individual fitness plus fitness through relatives, or kin selection

display coalitions in male turkeys

2 males display together but only one gets to mate

coalition males were close relatives

dominant males had way more offspring than solos and subordinates, benefits outweighed costs even for subordinates

eusociality

societies with obliagate extreme altruism; reproductive caste (makes young) and worker caste (everything else for group)

reciprocal altruism

helping non-relative can be beneficial if they help you

allogrooming in female macaques

females groom and aid allies in fights

not correlated w relatedness, but supported those who groomed them

chimpanzee image scores

studied captive chimps

chimps watched people share or not share grapes

most chimps preferred those who shared