The mating system of the hamadryas baboons is classified as female defense polygyny. Case notes that female defense polygyny occurs because the females often live in social groups for protection, but not in a range that can be defended. Instead of defending a territory, in these cases, males defend the group of females (Case 2004). In the case of the hamadryas baboons, they live in a large home range that can be from 1km 1-40 km2. The hamadryas baboons needs such a large home range because they live in semi-desert areas and food is not as plentiful so they often have to travel within their range searching for food. Additionally, since the food is season in horn of Africa, the hamadryas baboons travel a lot during the dry season in order to find food. Therefore the male hamadryas baboons males often attach themselves to groups of females and defend these groups against other males, rather than attaching themselves to a piece of real estate.
There are several strategies for one male unit leader and the males associated with the one male unit. Each young adult male hamadryas baboon tries to become a one-male unit leader and each male may defend up to ten females in a one male unit. The one male unit leader is the only one who mates with the females. The one male unit leader has developed strategies to keep his females. The one-male unit leader will often herd the females at all cost in order to prevent interaction with other male hamadryas baboons. The one male unit leader will often use a following and procession technique where he will often stop to look and stare at every step to hurry his female( Kummer 1968). The sternest punishment inflicted towards a female baboon who strayed from the one-male units was a bite on the back nape inflicted by the one male unit leader. “ Juvenile females are allowed more freedom of movement than adult females, except where the female is the male’s only female( Kummer 1968). Additionally, the one-male unit leader may threaten other males to keep them at a distance( Kummer 1968). The follower males also to adopt certain strategies to gain access to females. The young adult males will often try to sneak copulation with females in the one male unit. Kummer notes “ it appears as though it is the females in estrus who introduce the young followers into the units( Kummer 1968). The young adult male become attached to the one-male unit as a followers. They are endeared and attached to the female who brought them into the one-male unit. Grooming between the female of the unit and follower males is accept by some one male unit leaders but some one-male unit leaders respond to it with threats (Kummer 1968). The follower males are attached to the one-male unit for a substantial amount of time until they form their own one male unit. Kummer notes that sub adult males have the tendency to kidnap young black is the earliest of several forms of maternal behavior exhibited by hamadryas baboons ( Kummer 1968). They kidnap young juveniles from their mothers to get accustomed to leading them.
Similar to the male, the females in the one-male unit have adopted certain strategies to gain access to other males . The females will often initiate the sneak copulation with young adults male. As noted above in the male strategies, the female’s sneaking copulation with the younger adult male will usually result in the younger males joining the one-male unit. Copulation with the follower males will leads to avoidance of conspecifics and increase in the genetic gene pool within the one-male unit. Furthermore, the females will gain helpers for their offspring as the sub adult males become endeared to them as followers in the one-male unit.
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This Page was created by Stella Kenyi, stkenyi@davidson.edu, as student website for Biology 323, Animal Behavior, At Davidson College