In most social species, it is the adolescent males who leave their natal group to join another, which prevents inbreeding. A son who remains in his natal group with his father may cause tension because the two rivals both want to mate with the females in estrus. However, in at least two species, mountain gorillas and lions, some fathers and sons have been comrades. This chapter highlights information about social grooming, which is especially important in many of the higher primates. This activity is significant in cementing friendships between a dyad, indicating social relationships to other members of a community, and, of course, combatting parasites.

Mountain gorillas

Beethoven, the alpha male of group 5, was living with four adult females and various young when Dian Fossey (1983) first encountered the group in 1968. The dominant female was Effie and it was her first infant, Icarus, who developed a strong bond with his father while growing up in this polygamous family. The members of the group did everything together: travel through montane forests and open regions to areas of food, rest in a bunch at midday, play and groom as feelings allowed, seek protection together from pelting rain, and build sleeping nests for the night. At first, Icarus spent all of his time with his mother, but as the months and years passed he became a fully fledged member of the group in his own right. He began to help take on the male role of group protector against other gorillas and poachers. When Icarus was 11 years old, he was still immature but eager to mount young Pantsy when she was in estrus. Like many human fathers, Beethoven did not like this; when he saw them getting together he would run at them and whack them apart before mounting Pantsy himself.