higher biology - unit 3.6: social behaviour

social hierarchy

a rank order within a group of animals consisting of a dominant and subordinate members

what types of behaviours do dominant individuals carry out?

ritualistic (threat) displays

examples of ritualistic (threat) displays

teeth bared, ears and hackles raised, head raised and eyes staring

what types of behaviours do subordinate individuals carry out?

appeasement

examples of appeasement

teeth covered, ears hackles and tail lowered, head lowered, eyes averted

what do ritualistic and appeasement behaviours aim to do?

reduce conflict

advantages of social hierarchy?

increase chances of species survival

what do social hierarchies increase in reference to genes?

the chances of the dominant animal's favourable genes being passed on to offspring

animals often form alliances to...

increase their social status within the group

co-operative hunting

predatory animals may hunt together to optimise energy gain and increase their hunting success

who does co-operative hunting benefit?

subordinate animals as well as dominant ones, as they may gain more food than foraging alone

benefits of co-operative hunting?

less energy used per individual, enables larger prey to be caught and increases chance of success

social defence

large groups of animals have a better chance of defending themselves against attack by a predator, than a small group

social defence increases survival how?

some individuals can watch for predators whilst others can forage for food

why do some animals adopt specialised formations?

to protect their young

altruism

unselfish behaviour which harms the donor individual but benefits the recipient

reciprocal altruism

one animal giving help to another animal in the prospect of the favour being returned

kin selection

the process by which evolution selects for individuals who cooperate with their relatives e.g. individuals reduce their own net lifetime production of offspring in order to help their relatives

what do donors benefit from in kin selection?

increased chances of survival of shared genes

social insects

insects that exist within a society in which each insect has a particular job or function

a division of labour exists in social insects such as...

food gathering, defence, reproduction

queen bee

female that produces eggs that are fertilised by drones to become workers, she also lays unfertilised eggs that become drones

drone bee

haploid males whole role is purely reproductive, to find and mate with a queen

worker bee

non-reproductive females that maintain and defend the hive. Collect pollen and carry out waggle dances to show direction of food

social insect examples

bees, wasps, ants, termites

primate care behaviour

long period of care to allow learning of complex social behaviour

what do complex social behaviours support?

the social hierarchy

social behaviours reduce conflict through

ritualistic display and appeasement behaviours

social behaviours lead to what forming between individuals?

alliances, which increase social status in groups

threat display

ritualised behaviour used to intimidate a rival without engaging in a real fight

threat display examples

swaggering, chest-beating, tail raised

appeasement behaviour examples

tail lowered, eyes lowered

body posture

used to emphasise position in a dominance hierarchy and avoid conflict

females use what to appease a dominant males?

sexual presentation