3.6 - Social Behaviour Flashcards
Behaviours Adapted For Group Living
Social Hierarchy
A system where members of a social group are organised into ranks due to aggressive behaviour e.g. wolves, chimps, and chickens.
Higher ranking members dominate lower ranking subordinate members.
Social Hierarchy Increases Survival Rate By…
- Allowing stronger animals to pass genes onto next generation
- Providing experienced leadership
- Saving energy
- Resulting in less aggression
Behaviours Adapted For Group Living
Cooperative Hunting
Predatory animals that hunt prey in groups.
The dominant animal receives first choice of food whilst the subordinate animals still benefit through gaining more food than if they were to gorage alone.
However, food sharing will only occur if the reward for sharing is greater than the reward for foraging individually.
Advantages of Cooperative Hunting
- If an individual is unsuccessful in bringing down prey, it can benefit from success of others
- Division of labour
- Larger prey is hunted compared to hunting alone
- Wider range of hunt as more to run down prey over larger distances
Behaviours Adapted For Group Living
Social Defence
Social groups working together to defend the group or raise alarm of dangers e.g. quail resting
Advantages of Social Defence
- Safety in numbers (more likely to avoid attack)
- Weaker/young are more likely to survive through protection
Altruism
An altruistic behviour harms the donor individual but benefits the recipient.
Donor loses resourcees –> Recipient gains resources
Reasons for Altruism
Reciprocal Altruism
A donor will help another organism at the cost of its own survival if the favour is likely to be returned.
E.g. vampire bats
Reasons for Altruism
Kin Selection
Behaviour that appears to be altruistic between related individuals (kins)
Genes are shared between related organisms so a donor will beenfit by acting altruistically as they are increasing their chances of survival of shared genes through the recipient’s offspring or future offspring.
Social Insects
Only the queen and drone contribute reproductively (produce offspring) in social insect societies.
Most members are workers who don’t reproduce. Sterile workers cooperate with other related workers to raise the offspring. This increases the sterile worker’s chance of survival of genes through the survivial of related offspring.
Examples: bees, wasps, ants, termites
Social Insects
Examples of Roles of Workers
- collect pollen
- defend the hive
- carry out waggle dance to show the direction of food
Primate Behaviour
Primates produce very few offspring but give high levels of parental care over a long period of time.
This gives offspring time to learn complex social behaviours that are essential for survival.
Parental Care Examples
- Feeding
- Cleaning
- Protection
- Transporting
- Defending
Behaviour to Reduce Conflict
Ritualistic Display
Threat display behaviours that show aggression without the need for physical fighting. E.g. Gorillas beating chest and roaring.
This occurs if there is intraspecific competition for the same niche.
Behaviour to Reduce Conflict
Appeasement Behaviour
Submissive displays to make the primate look as unthreatening as possible. E.g. avoiding eye contact, grooming others and crouching
Lower members of a social hierarchy display appeasament behaviour to appear subordinate by looking small and motionless towards the dominant members.
Other Behaviours
Grooming
- Reciprocal altruism by removing parasites
- Reduce tension and act as reconciliation
- Cement friendships and alliances
Other Behaviours
Facial Expression
Used by subordinate individuals to appease a more dominant male.
E.g. closing eyes during an encounter or grinning and opening the mouth
Other Behaviours
Body Posture
A subordinate acting in a servile manner to a more dominant male.
E.g. bowing or emitting soft, grunting noises
Other Behaviours
Sexual Presentation
Females use a sexual approach to offer an alternative to aggression.
