3.6 Social Behaviour Flashcards
describe ‘social hierarchies’
When animals live in lose proximity, the level of competition between individuals, for resources, increases.
Animals that live in social groups have overcome this by developing social hierarchies, where the group consists of dominant and subordinate members, and individuals are aware of their rank within the group.
Conflict within the group is further reduced by dominant individuals carrying out ritualistic displays (threats) while subordinate individuals respond with appeasement behaviours.
what are the benefits of a social hierarchy?
- limits violence within the group
- increases the chance of the dominants favourable genes being passed on to offspring
- can hunt/forage more effectively
- the weak/young can be protected and cared for
- animals can form alliances to increase social status
describe ‘cooperative hunting’
Meat-eating animals that live together in social groups can also benefit from taking part in cooperative hunting. These animals hunt together in a coordinated way, allowing the division of labour, and the allocation of roles within the hunting party.
what are the benefits of cooperative hunting?
- individuals gain more food than by hunting alone
- less energy is used per individual
- enables larger prey to be caught
- increases the chance of success
describe ‘social defence’
groups of animals (usually prey species) can also work together to defend the group, particularly when they are young and present, by raising the alarm, mobbing attackers or taking up a defensive formation
what are the benefits of social defence?
- safety in numbers — avoids attacks
- the weak/young members have increased survival if defended by the group
describe ‘altruistic behaviour’
Altruistic behaviour is when the donor is harmed by giving it to the recipient, who benefits.
Altruistic behaviour tends to be more common between individuals that are closely related. This is known as kin selection
Although facing a loss themselves, donors of altruistic acts benefit from the behaviour indirectly because there is an increased chance of shared genes surviving in the recipients offspring or future offspring.
If the altruistic behaviour is later returned, with the donor and recipient swapping roles, then this is known as reciprocal altruism.
give examples of altruism
- vampire bats sharing a blood meal with a starving neighbour (donor loses energy by sacrificing some of its food and the recipient gains a blood meal)
- meerkats standing guard while the rest of the group feed (donor doesn’t get food and the recipient can feed without having to watch for predators)
describe ‘social insects’
An extreme form of kin selection can be seen in the social insects.
Some species of bees, wasps, termites and ants live in social groups where only a few individuals reproduce, and most are sterile.
The sterile individuals are workers that cooperate with other closely related individuals within the colony to raise other relatives.
The workers carry out most of the other roles found within the colony, such as defending the hive, collecting the pollen and carrying out the waggle dances to show the direction of food.
describe ‘primate behaviour’
Some of the complex social structure s among animals can be found in the primates, as the majority of primate species, including humans, spend their lives living in large social groups.
Most primate groups have some form of social hierarchy, helping to reduce conflict within the group.
The rank of an individual is usually inherited from its mother.
how do primates ensure offspring are aware of, and able to navigate the intricacies of social living?
they have long periods of parental care that allow offspring to learn complex social behaviours of the group.
give examples of ritualistic displays in primates
- hooting
- chest beating
- teeth bearing
give examples of appeasement behaviours in primates
- facial expressions
- body posture
- grooming
- sexual presentation
how could subordinate individuals increase their social status within the group?
by forming alliances (friendships) with more dominant individuals
