Behavioral Ecology - Cooperation

What are two ways in which individuals know if they’re related?

1) Direct genetic kin discrimination: Closer relatives would have similar traits, such as scent. Ex: Armpit effect
2) Environmental cues: Individuals tend to treat others in their “home” as kin. Ex: Imprinting

What is Hamilton’s Rule state?

Altruism will be selected for when the cost of helping is less than the benefit to the recipient weighted by the relatedness to the donor

What is Hamilton’s Rule equation?

r*B > C

Relatedness * benefit to recipient > cost to donor

What is cooperation?

Provides direct fitness benefits to both the donor and recipient, and has been selected for because of these benefits

What is an example of three species that display cooperative breeding?

1) Dwarf mongooses
2) Long-tailed tits
3) Florida scrub-jays

What are the three hypotheses for cooperation?

1) Byproduct: Cooperation can provide a benefit to a recipient as a byproduct of an otherwise selfish act by the donor
2) Reciprocity: Helping another individual because that individual will then help them back
3) Enforcement: Rewarding cooperation and/or punishing “free riders” (cheaters)

What is an example of two species that display the byproduct hypothesis?

1) Ants
2) Meerkats

What is an example of a species that displays the reciprocity hypothesis?

1) Vampire bats

What is an example of a species that displays the enforcement hypothesis?

1) Cleaner wrasses