62 Hierarchies in Baboons

Key Idea: Dominance hierarchies help maintain social order and reduce conflict. Baboons have a highly developed social structure with a dominance hierarchy. Dominance hierarchies are most commonly seen in males, who are usually not related and aggressively compete over higher positions and access to females. Females also have hierarchies but these are often based on mother-daughter relationships. Once established, hierarchies are usually maintained by gestures, facial expressions (e.g. yawning to show canine teeth), and ritual aggression. Fighting usually occurs when one male wishes to increase his status and rise in the hierarchy.

` Olive baboons (Papio anubis) live in the savannah regions of Africa and have a highly organised and complex social structure. Within a troop of baboons (see below) an orderly hierarchy promotes division of labour within the group, reduces conflict, and maximises the efficiency with the which the group can search for food and defend itself against predators and other troops. ` The adult males are distinguished by their large size and well developed manes. Females with babies are positioned near the centre for protection. The two females in oestrus (sexually receptive) move in consort with the most dominant males. All males (with the exception of the dominant males) tend to be positioned on the edges of the group. Should any threat be encountered in their march, the dominant males will move to the front, with the subordinate males in support. The females, adolescents and babies move to the rear, away from the threat.

Females with young Female in oestrous Dominant male

Subordinate adult male Subordinate adult male

Adolescents

Female in oestrous Dominant male

Source: Hall and De Vore, 1965

1. Explain how an individual baboon (regardless of its social ranking) may be more protected by being within the troop:

2. Describe one feature of the social structure of the baboon troop that gives additional protection to its members:

3. Baboons have some of the most ferocious canine teeth of all primates, and are capable of inflicting massive injuries.

Explain how a dominant baboon male keeps order in his troop without maiming:

4. (a) How might a subordinate male improve his status in the hierarchy?

(b) What resources would he gain by doing this?