Social Behaviour Flashcards
What are the advantages of living in a social group?
Protection
Easier to catch food
Easier to find a mate
Have help with raising young
What is a social hierarchy?
A system where members of social groups are organised into a rank order resulting from aggressive behaviour between different members of groups
A high ranking individual dominates the subordinates
Advantages of a social hierarchy
Increase species chance of survival because:
- agression between members is ritualised so real fighting is kept to a minimum avoiding serious injury
- energy is conserved
- experienced leadership is guaranteed
- most powerful and fittest will pass on genes to next generation
What is co-operative hunting?
Predatory mammals often hunt together as groups to increase their hunting success
Advantages of cooperative hunting
All members of a group get a share and benefit (although dominant animals get more)
They can tackle larger prey so gain more food than hunting alone
Minimises injury
Social mechanisms of défense
Safety in numbers - staying in a large group protects many animals from predators as there are many eyes to look out for predators and alert the group and it is harder for predators to pick out one animal
Defensive formation - females and young in the centre
Strict social hierarchy - always march in a certain order
What is altruistic behaviour?
Unselfish behaviour which is detrimental to the donor and beneficial to the recipient
Two types of altruistic behaviour
Reciprocal Altruism
Kin Selection
What is reciprocal altruism?
One animal giving help to another animal in the prospect of the favour being returned
What is Kin selection?
Where individuals reduce their own net lifetime production of offspring in order to help their relatives reproduce
May involve personal sacrifice but it is not a sacrifice in evolutionary terms
It is a sacrifice where the benefits outweigh the costs
Why do social insects express extreme altruism
Kin selection
Workers are sterile yet they help their siblings survive and reproduce so the shared genes are still passed on
Features of social insects
A division of labour exists:
Food gathering/defence = sterile members
Reproduction = few fertile individuals
Three types of honeybees
Queen: female that produces eggs
Drones: haploid males whose role is purely reproductive, to find and mate with the Queen
Workers: nonreproducing females (all sisters) that maintain and defend the hive rather than reproduce
(Drones and workers are the Queen’s offspring)
Describe signalling in honeybees
Workers perform a waggle dance to communicate:
- The distance of food
- The direction of food
- The richness of the supply
They do this to minimise energy expenditure by other members of the hive
Describe social behaviour in ants
Ants search for food in a snaking pattern
They leave scent markers for other ants to follow the trail
What is a keystone species?
Play a critical role in the structure and working of an ecosystem
Their absence could lead to instability and collapse of an ecosystem
What are ecosystem services?
The benefits to humans provided by natural ecosystems
E.g. pollination
Describe parental care in Primate behaviour
Small number of offspring but take great care of them:
Feeding, cleaning, protection
Young primates have time to learn complex social behaviours including communication
Describe ritualistic threat displays
Exhibit a threat display that makes them look larger and fiercer
One will make itself more intimidating and the other will then concede defeat and adopt appeasement behaviour
Describe appeasement behaviour
Body made to look smaller, flatter, motionless and unthreatening
Females and subordinate males use appeasement behaviours to show acceptance of dominant male
Reduces needless hostility
Examples of appeasement behaviour and benefits of it
Grooming, facial expression, body position, sexual presentation
Reduces tension, prevents conflict, establishes dominance, avoid aggression
How can social status within a social hierarchy change?
Not always static and may change such as through alliances
What is the social structure of private societies related to?
Ecological niche
Resource distribution
Taxonomic group
What is group size and organisation of social structures affected by?
Predator pressures
Availability and distribution of resources
