predation, foraging Flashcards
2 critical behavioral components of survival are?
finding food (feeding)
avoiding predators (foraging)
what are the 2 basic appraoches to study foraging and predation?
- evolutionary game theory
models dynamics of interactions by assessing strategies based on what others are doing, and then determines which strategies are more likely to evolve - optimality theory
predict best way an animal should behave, in terms of maximising fitness benefits and reducing fitness costs
what is the evolutionary stable strategy
the optimal solution
a single strategy in a population that cannot be overtaken by another strategy that is initially rare
hawk-dove game definition
this game establishes a payoff scheme and advantage depends on the ____ and the _______ of hawks and doves in the population.
individuals are in competition over food, and can choose either hawk or dove strategy
- hawk - win all or lose all
- dove - retreat if attacked, share if other is cooperative
payoffs; frequency
active vs passive group defense
active group defense - mobbing and vigilance
passive group defense - living in groups, safety in numbers
cost of mobbing: nest boxes with mobbing calls around them lose ____ eggs to _____.
more; pine martens
costs of alarm calling (vigilance) - fork-tailed drongos in South Africa _____ alarm calls of other birds. These fake calls scare the foraging birds away and the drongos and feed better.
mimic
dilution effect hypothesis
forming groups make it more difficult for any individuals to be depredated compared to being alone
moving as a group reduces possbility of being depredated because the crowd of moving prey targets confuses the predator and disrupts ability to single out individual - what’s this effect called?
confusion effect hypothesis
what is the selfish herd hypothesis
individuals in a group actively try to reduce own risk of depredation by positioning themselves so other group members are between them and approaching predators
butterflies drink fluids high in sodium and nitrogen in groups for the ______ effect hypothesis.
dilution
which animal uses both dilution and confusion effect hypotheses to avoid predation?
european starlings (sturnus vulgaris)
___________ animals will take fitness loss when exploited as predator shield while ___ individuals benefit. when social animals pair up, they are equally likely to share benefit.
solitary; social
what is cryptic coloration known as?
camouflage
camouflage is also known as ________ _____________. it _________ the animal to the ____ they normally utilise/rest at.
cryptic coloration; matches; substrate
in peppered moth (biston betularia), melanic phenotype is darker/lighter than the peppered phenotype.
in polluted woodland due to industrialisation, which moth survived better?
darker
melanic
which animal has aposematic coloration? how and why?
monarch butterflies. bright colors serves as warning signals that the butterflies are chemically defended and toxic due to milkweeds they consumed as caterpillars which also possess aposematic coloration.
blister beetles have this noxious chemical in their blood that defends them from predators. they can mat for hours atop flowers with no threats at all. what is this chemical?
cantharidin
mammals heavily defended usually have smaller/larger brain size, perhaps a _________ trade-off in costs.
metabolic-developmental
what are the 2 kinds of mimicry?
- batesian mimicry - non toxic animal mimics a toxic one
- Müllerian mimicry - noxious species converge to look like each other