Transcript Document
Primate social groups http://www.youtube.com/watch?v=kHNd7rAHNPY Social Behaviour in Primates • Primates are a group of mammals that include apes, monkeys and lemurs. • Most primates live in trees and have: – flexible forelimbs with opposable fingers and thumbs – well-developed eyes with binocular vision – large brain – high degree of parental care to young • Primates live in family groups in which: – young are protected until they are sexually mature – hierarchy within the group with • status • different roles http://video.nationalgeographic.com/video/gorilla_lowland_ odzala Gorilla • Gorillas live in family groups or troops of about 10 individuals comprised of a: – dominant male or silverback – several females – their young • Males leave the troop as they mature, females leave or sometimes stay • Silverback is the only male to mate with the females in the troop – protects the members of the troop – leads the search for food • Gorillas have a high level of maternal care and group protection allowing for: – increased survival – skills acquisition by: • imitation • play learning http://www.youtube.com/watch?v=z5oznbdFqaQ • Grooming is important – reinforces bonds – helps remove parasites • Communication is by a mixture of: – vocalisation • calls and grunts – facial display Advantages of Social Behaviour There are many advantages of gorilla social behaviour: 1. food search is more efficient 2. greater protection – more eyes to spot potential predators 3. position and relationships are reinforced 4. reproductive success is greater – care of the young 5. Learning complex behaviours Chimpanzee • Chimpanzees live in large communities made up of several groups whose composition may change regularly – all male – all female – mixed sex groups • Within the groups there is a hierarchy, e.g. – alpha and beta males Male Chimpanzee, Pan troglodytes • Chimpanzees have a high level of maternal care and group protection allowing for: – increased survival – skills acquisition by: • • • • imitation tool use play learning http://www.youtube.com/watch?v=5Cp7_In7f88 • Grooming is important: – reinforces bonds – maintains relationships • dominance and subordinate roles – helps remove parasites • Communication is by a mixture of: – vocalisation • calls and grunts are used to communicate a range of emotions and information • pant hoot – series of calls of rising and falling pitch, ending in a scream – can indicate site with plenty of food, a fresh kill by a hunting party or response to a charging display – facial display http://www.youtube.com/watch?v=yEF0z5IS5DA • pout face with eyes open and lips pulled into an ‘O’ shape • indicates frustration or anxiety following, for example, an attack or rejection of grooming – body language • arm raising with palm outwards • this is a low intensity threat to a subordinate Advantages of Social Behaviour There are many advantages of chimpanzee social behaviour: • food search is more efficient • hunting is more efficient – chimpanzees do hunt for meat, especially the males • greater protection – more eyes to spot potential predators • • • • position and relationships are reinforced reproductive success is greater care of the young learning