Animal Behavior: Group living and social behaviour lecture 2 Flashcards
What are Primates?
-Primates are uniquely social compared to other mammals
- Involves “ social attraction”
- seek proximity to one another independently of environmental stimuli
- Primates want to be together when not particular function
- their social organization is more complex than other animals
- argued that sociality is thought to be at the very core of primate existence- it is a primate’s principal evolutionary strategy, and what makes them different from all other species
- differentiated withing group relationships
- marked social boundaries
- occurence of kin - biased social relationships
- influence of allies in some species
- combination of each of these features in unique in each primate species
- Primates form groups because mixed - sex groups that are together year- round are rare amongst mammals
- group living is costly
- factors associate with group- living reduce individual reproductive success
What are the costs to group living?
- more easily attract predators
- competition for access to food or mates
- increased food requirements, increased time spent searching for food
- increased disease transmission
what are the benefits to group - living
- resource defence hypothesis
- predation hypothesis
- can out compete other groups in inter- troop competition
- more individuals means more knowledge of resources
- detection: more eyes to see predators
- more individuals to band together to mob a predator
- less likely to be eaten by a predator via the “ dilution effect”
what is resource defence hypothesis?
-Being in a group improves access to resources for individuals compared to being alone
- being in a group improves the ability of females to find and defend resources - they couldn’t do this as well if they were alone with infants
What is predation defence hypothesis?
3Ds
- detection: more eyes to see predators
- detterence more individuals to mob a predator
- dilution: less likely to be eaten by a predator via the “ dilution effect
What is philopatry?
when an individual shows the tendency to remain in their natal group
what is female philopatry?
when females in a species show the tendency to remain in their birth group for their lifetimes
- females are matrilocal ( they live in the same group as their maternal kin)
- matrilines form( females are related to one another through maternal descent)
what is male philopatry?
when males in a species stay in their birth group
- males are patrilocal: they live in the same group as their paternal kin
- male patrilines form: males are related to one another through paternal descent
what is dispersal
refers to the emigration from a social group ( leaving a group)
what is male- biased dispersal?
males typically leave the group
- is most common type in mammals and primates
- is found where females are philopatric
what is female - biased dispersal?
females leaving the group
- occurs with male philopatry; less common
What are the reasons for dispersal?
- inbreeding avoidance
- better mating opportunities elsewhere
- competition over resources
What is solitary/ semi - solitary?
Offspring live w/ mother until old enough to fend themselves
- animals only come together to mate
what is pair living?
one male, one female and offspring
- live together in same territory or home range
What is is single - male groups?
- used to be called “harems”
- 1 male with 2 or more females
- some “bachelor” groups w/ this type of social system