Avoiding Predators and Finding Food Flashcards
Convergent and divergent evolution
look at behavioral characteristics in
closely/distantly related species to help explain how a behavior evolved as
a result of the environment.
Cost-benefit
approach to analyze traits and behaviors in terms of fitness.
Dilution effect-
larger groups make it less likely that one individual gets picked off.
Game theory
involves decisions viewed as a game played by competitors, where the best strategy depends on what others are doing.
Deceptive Signal
sender gives a false signal to manipulate the behavior of the receiver
Optimality Theory
Optimal traits have the best benefit-to-cost ratio. Generate hypotheses about the adaptive value of traits in terms of net
fitness.
Landscape of Fear give an example
fear by prey of predators influences foraging and the movement of animals
ex. Elk patterns were altered by the presence of wolves not only direct predation.
Frequency-dependent selection give an example
fitness of one strategy is a function of
freq. of another inherited trait. – lack of flexibility
ex. sitter and roamer fruit fly larva. The most successful is the less frequent one.
ex. African Cichlid turned mouth
Conditional strategy
involves an individual’s ability to adaptively alter its behavior in light of the conditions it confronts.
Confusion Effect hypothesis
moving as a group may reduce the likelihood of predators capturing prey because of their inability to single out and attack an individual
Selfish Herd give an example
A group of individuals whose members use others as a living shield against predators.
ex. Bluegill nesting colonies dominant individuals stick to the center.
Marginal Value Theorem
*Animals should leave a patch of resources when the food intake
drops below the average rate for that habitat
*At first an individual can gain a lot of resources form a patch of
land but over time there is a diminishing return.
*Animals will stay longer in a patch if travel time between
patches is great or if quality in a partial patch is higher then the
average in the environment.
Cost Benefit Mobbing Behavior
Arctic turn and non-cliff dwelling gulls. It is a distraction to protect offspring. Cost: expenditure of energy Benefit: social harassment protects their eggs and
chicks
Fitness Indicators
egg survival
number of young that survive to fledge,
number of sexual partners
quantity of food ingested/time
Parsimony
Choose the simplest scientific explanation that fits the evidence. (Apply to phylogeny)
Social defense
include shared vigilance, and communal defense. One squirrel kicks sand at a rattlesnake, while others give a variety of
alarm signals. Snake mob of ground squirrels.
Give an example of dilution and confusion effect
Dilution: Harvester ants gather for mating, and dragonflies take advantage.
Confusion: European Starlings as the flock
increased target errors also increased
Give an example of environment-changing fitness
Due to the peppered moth’s cryptic behavior, the Industrial Revolution favored black over peppered-colored moths.
Cryptic Behavior
Camouflage. Cost: finding the right place to hide.
Conspicuous Behavior
Possible Benefits: scare predators, Aposematic coloration(I’m poison), deception (Batesian mimicry), Honest signal
ex. whistle from peacock butterfly and sphinx caterpillar(scare), Monarch (aposematic), flies mimic jumping spider, Antelope jump
Northern Bobwhite Colonies
Numbers fall in the calculated optimal size ranges to maximize benefits of group and minimize costs.
Blue Whale Graxing
example of Marginal Value Theorem because they base feeding strategy to maximize energetic efficiency.
Zebra Finch
highest caloric gain is proportional to the highest reproductive success.
Optimal Foraging models.
make predictions of how an animal will maximize fitness while foraging. Take into account predation risk.
ex. Dugongs(Sea cows) alter foraging tactics when predators are near.
Ruby Turnstone foraging on the beach
Conditional strategy. 3 strategies based on rank. The best strategy goes to the most dominant.
