Animal Behavior Test 3

benefits of parental care

increases the survival and quality of the offspring

costs of parental care

• time and energy invested can’t be used for maintenance, growth, or producing more offspring

• increased predation or injury risk when protecting offspring

life history theory

animals should evolve reproductive strategy that maximizes lifetime reproductive success

• increased parental care increases present reproductive success and decreases future reproductive success

life history traits

• age of sexual maturity

• reproductive pattern (seasonal vs year round)

• number of offspring per clutch

• investment in each offspring (parental care)

nest predators

predators can follow provisioning parents back to the nest (harms current reproductive success)

adult predators

predators can wait at the nest for the parents (harms future reproductive success)

parental care

strategy that increases current reproductive success at the cost of future reproductive success

who provides the care?

maternal care is more common than paternal (there is variation)

• fish: paternal is more common

• mammals: maternal is more common

• birds: biparental is more common

fundamental asymmetry of sex

females invest more into producing the egg, so she has more interest in ensuring the offspring survive

sunk cost fallacy

optimal decisions should depend on future pay-offs, not past costs

maternal certainty

there are less ambiguity over whether the offspring is genetically the mother’s

• males only care when they are certain that the offspring is genetically theirs

good fathers provide benefits

females prefer males that provide better parental care

• females prefer males that are currently caring for eggs because it signals that they are good fathers

cost asymmetry

when the cost of parental care is lower in males than in females, male care are more likely to evolve

paternity assurance

by performing parental care, males can ensure paternity

harsh environment

when condition is harsh, male care in addition to female care is required in order for any offspring to survive

offspring recognition

parents need to identify their own genetic offpsring and not mix them up with unrelated young

• parents will use visual, olfactory, or acoustic cues to recognize their offspring

brood parasitism

when one species exploit another species’ parental care to raise their young

• manipulating another species into taking care of their offspring

imperfect discrimination

parents may destroy their own eggs while trying to get rid of parasitic eggs

• aggressive mimicry by the brood parasite makes the discrimination more difficult