Hamadryas Baboon - Social Life - Group Behavior

Group Behavior

The hamadryas baboon is unusual among baboon and macaque species in that its society is strictly patriarchal. The males limit the movements of the females, herding them with visual threats and grabbing or biting any that wander too far away. Males will sometimes raid harems for females, resulting in aggressive fights. Some males succeed in taking a female from another's harem, called a "takeover". Visual threats are usually accompanied by these aggressive fights. This would include a quick flashing of the eyelids accompanied by a yawn to show off the teeth. As in many species, infant baboons are taken by the males as hostages during fights. However, males within the same clan tend to be related and respect the social bonds of their kin. In addition, females demonstrate definite preferences for certain males, and rival males heed these preferences. The less a female favors her harem males, the more likely she will be successfully taken by a rival. Young males, often "follower" males, may start their own harems by maneuvering immature females into following them. The male may also abduct a young female by force. Either way, the male will mate with the female when she matures. Aging males often lose their females to followers and soon lose weight and their hair color changes to brown like a female. While males in most other baboon species are transferred away from their male relatives and into different troops, male hamadryas baboons remain in their natal clans or bands and have associations with their male kin.

Hamadryas baboons have traditionally been thought of having a female transfer society with females being moved away from their relatives of the same sex. However, later studies show female baboons retain close associations with their female kin throughout their lives. Females can spend about as much time with other females as they do with the harem males, and some females will even interact with each other outside of their harems. In addition, it is not uncommon for females of the same natal group to end up in the same harem. The males likely restrict female bonding in hamadryas baboons rather than ecological factors. Females can still associate and help their extended families despite their interactions being controlled by the harem males.

Females within a harem do not display any dominance relationships as seen in other many other baboon and macaque species. The harem males suppress aggression between the females and prevent any dominance hierarchies from arising. Despite this, some social differences between the females occur. Some females are more socially active and have a stronger social bond with the harem male. These females, known as the "central females", stay in closer proximity to the harem male then the other females. Females that spend most their time farther from the harem male are called "peripheral females".