3.6 - Social Behaviour

• Many animals live in social groups for increased survival due to protection, cooperative hunting, and division of labour
• Social hierarchy organises individuals into an order of rank with dominant and subordinate behaviours
• Subordinate individuals carry out appeasement behaviours to reduce conflict
• Co-operative hunting benefits the whole pack by increasing success rate, tackling larger prey, and using less energy per individual
• Benefits of staying together in a large group

  • Some individuals can look out for predators while others eat
  • A group will seem more intimidating to a predator
  • When the group is attacked they can work together to defend themselves
  • Individuals have a better chance of surviving an attack
• Defence formation


  Groups adopt a specialised formation during an attack, e.g., musk oxen forming a tight circle and facing outwards ready to defend themselves with their horns
• When baboons are on a march, dominant males stay in the centre with females with young. Lower ranking males and juveniles keep to the edge of the troop and raise the alarm if the group is threatened by a predator
• Altruism is unselfish behavior where an individual may behave in a way that is detrimental to itself but beneficial to another individual, the recipient
• Reciprocal altruism occurs where the roles of the donor and recipient are later reversed, often seen in social animals like vampire bats feeding each other blood
• Some insect societies, like bees, wasps, ants, and termites, have evolved complex social behavior resulting in close cooperation between individuals
• Roles in insect societies

  1. Reproductive caste: queen and drones for reproduction

  2. Worker caste: sterile individuals performing tasks like feeding, caring for young, gathering food, building nests, and defending the colony
• Primates invest a great deal of parental care in their offspring and learn complex social behaviors essential for survival like communication, cooperation, and sharing
• Threat display in primates

  Competing social primates exhibit threat displays, also known as ritualistic displays, to look larger and fiercer than normal. Eventually, one concedes defeat by displaying appeasement behaviors like grooming, facial expressions, body postures, and sexual presentation
• Primate


  • Features of ritualistic behaviour: Chimpanzee - Shoulders hunched, arms held out, mouth open, teeth covered by lips; Gorilla - Chest-beating, roaring, strutting walk, eyes staring; Vervet monkey - Head bobbing, mouth open, tail arched over body
• Ritualistic displays and appeasement behaviours are important as they can reduce unnecessary conflict within a close-knit group, increasing the chance of survival
• Alliances often form between individuals to increase social status within the group