Topic 11 A: Sociality, altruism

Potential Costs of social living

• Greater conspicuousness of clumped individuals to predators

• Greater transmission of diseases and parasites

• More competition for food

• Time and energy expanded for subordinates in dealing with dominant companions

• Greater male vulnerability to cuckoldry

• Greater female vulnerability, egg tossing, egg dumping, and other reproductive interference by companions

Potential Benefits of social living

• Defense against predation- dilution effect, or mutual defense

• Opportunities to receive assistance from others in dealing with pathogens

• improved foraging

• Subordinates granted permissions to remain safely within the group

• opportunity for some males to cuckold others

• opportunity to toss eggs of others, dump eggs in other nests- and interfere with the reproduction of competitors

Cooperation

1. Mutualism

2. Reciprocal altruism

3. Facultative altruism

1. Mutualism

• interspecific mutualism

• intraspecific mutualism

  • a) Allopreening

  • b) Allogrooming

Alloparental Care

• 3 options for young males who are old enough to reproduce

a) Help their parents in raising young -primary helper

b)help unrelated adults raise their young - secondary helpers

c) don’t help anymore- delayers (selfish)