Social behaviour Flashcards
What are the different patterns of social organisation?
- stable closed social groups
- fission fusion social groups with individual recognition
- fission fusion social groups without individual recognition
What are stable closed social groups?
- individuals aren’t able to join (group members will repel/fight those that try)
- may even expel individuals from within the group
- individuals often interacting with kin
- typical of co-operative breeders
- species that come together and live in social groups and cooperate in the care/rearing of young
What are fission fusion social groups with individual recognition?
- individuals join and leave groups, move between groups
- societies are individualised
- individuals recognise other individuals within those groups, builds relationships with them, may cooperate with them
- may avoid individuals they’ve had negative interactions with
What are fission fusion social groups without individual recognition?
- individuals join and leave groups, move between groups
- assort based on phenotypic traits
Definition of fission fusion social groups in general?
- join and move between groups, adjusting size of group they’re in to reflect the prevailing costs/benefits of group living
- when there’s assortment by body size/phenotype it can lead to confusion of the predator
What are multilevel societies?
-almost a blend of stable family groups and a fission fusion system
Example of multilevel societies?
- killer whales
- matrilineal groups develop and grow around a female and her offspring stays with her
- multiple matrilines that swim together are called a pod
- matrilines can separate and go off on their own but can come back together
What is a selfish herd?
- for many, living in a group is a selfish
- often behave in a way that increases their own fitness at costs to others
What is direct and indirect fitness?
- direct fitness is based on number of offspring that an individual produces
- indirect fitness is based on the number of reproductive success of an individual’s relatives
Definition of inclusive fitness?
- individual’s total fitness based on both number of offspring it produces and the reproductive success of its relatives
- combo of direct and indirect
Example of inclusive fitness?
- Pied Kingfisher
- nest colonially in tunnels in large banks
- some males are unable to find mates
- primary helpers: bringing fish to their mother and nestlings, attack predators
- secondary helpers: help at unrelated nest
- delayers: sit out the breeding seasons and wait for next year
What is kin selection?
- inclusive fitness models consider effect of gene not only on the individual that carries it but also on genetic kin carrying identical genes by decent
- captured by Hamilton’s rule
- natural selection more strongly favours kin helping when relatedness is high and when benefits are high the costs are low
What is Hamilton’s rule?
- genes should increase in frequency when: RxB>C
- R is genetic relatedness of recipient to the actor
- B is the additional reproductive benefit gained by recipient of altruistic act
- C is the reproductive cost to the individual of performing the act
Definition of primary helpers?
- demonstrate that altruism can be adaptive
- i.e. raising their fitness indirectly by helping at the nest
Definition of secondary helpers?
- shows that helping may not be altruistic
- i.e. by helping they increase their future chances of reproduction
