Social Interactions Flashcards
Define social behaviours
Interactions among individuals of the same species
Many of the social behaviours observed in animals are adaptive
Balance of conflict and cooperation
Generally mediated by costs and benefits that are associated with living socially
What is involved in cooperation?
All cooperation involves acts by one individual (X) that benefit one or more other individuals (Y)
Focus often on costly acts by individual X that benefit Y
More recently includes cases where acts by X benefit X and Y
What are the range of cooperations considered in social interactions?
Kin selection
By-product mutualism
Reciprocity
Enforcement/manipulation
Describe kin selection
Most familiar and well studied path to cooperation
Recognised that individuals are more prone to cooperate and help relatives
Linked to the ideas of altruism
We need to consider inclusive fitness (inclusive fitness - direct fitness + indirect fitness)
What is Hamiltons rule?
rB-C > 0
If the benefit of the act is worth more than the cost (i.e. >0) then kin selection is favoured
Give an example of kin selection
Long tailed tits (Aegithalos caudotus)
Small bird which breed in most of Europe and Asia
- non breeding season, live in winter flocks of around 16 individuals
- overlapping generations from 1+ families; unrelated male and female migrants
- during Spring, monogamous pairs form, all birds start to breed independently with no helpers
- many nests fail, some birds rebreed while other go and help chicks at other nests
- helpers usually related in some capacity to those they help
What is by-product benefit?
Cooperation can provide a benefit as a by-product
Cooperation is always the best option from an individual or selfish perspective but that it also provides a benefit to others
Shows how cooperation evolves in non-relatives
Illustrated with a cooperative hunting game that has been referred to as the “prisoners delight”
Give an example of by-product cooperation
Meerkats live in groups of up to 20 adults plus young
Successful breeding = help from the suboridnates
Helpers increase group size = group augmentation
Group augmentation benefits include larger groups providing benefits to all its members and inheritable positions
What is reciprocity?
Paying back a favour in the future: A helps B today, B helps A tomorrow
Individuals that preferentially help those that have helped them in the past can have short-term costs repaid
However, problems can emerge in the possibility of free riding
Owing to the time delay between repayments
B may accept favour from A today but refuse to repay tomorrow
Give an example of reciprocity
Impala (Aepyceros melampus)
Allogrooming, where partners exchange grooming bouts
Each grooming bout is initiated by the groomer
Dominant recieves no more exchanges than the subordinate
Recipient: reduces tick infestation
Actor: electrolyte loss
What is enforcement cooperation?
Enforcing cooperation via punishment, policing and sanctions
Give example of enforcement cooperation via harassment
Meerkats - one month before female gives birth she develops aggression towards suboridnates driving them from the group until the birth of her litter
- aggression is to prevent others from getting pregnant or those who are from taking attention from her offspring
- Those driven away return to the group and maintain subordinate role
Give example of enforcement cooperation via punishment
Cleaner fish (Labroides dimidiatus)
- lives on coral reefs and removes and eats ectoparasites
- parasite removal and food acquisition benefical to both client and cleaner
Client fish punish cleaner fish that cheat and eat tissue instead of parasite
- aggressively chases cleaner away or switches partner
- cleaner fish found to change behaviour after punishment
