Hamadryas baboon

A CLEAR HIERARCHY

If you can be sure of one thing, it's that there's always something going on with the Hamadryas baboons in the zoo – and they've been the main characters in several wild stories over the years.

Hamadryas baboons live in a so-called patriarchy. This means that a larger group of females is led by one dominant male. His job is to protect the group from predators and rival males – and to maintain his position in the hierarchy. A typical family group consists of this male, about 10 females and their young, as well as some loosely associated males who participate in social life. However, the dominant males do not tolerate the loosely associated males mating with the females – and if they do, it can have fatal consequences!

Several of these family groups often join together to form even larger groups. A group typically consists of 2-3 smaller family groups. The social relationships across groups are important and are expressed, among other things, through mutual grooming or minor conflicts over resources.

The dominant male baboon is easy to recognize. He has a thick, flowing coat that females do not develop – they remain brown. The male rules the family pack with a firm hand and establishes his position through visual threats, for example by showing his teeth. If the females move further away than he likes, he can escalate the behavior and resort to more aggressive means. He can both bite and grab the females.

A dominant male can also try to recruit new females from other family groups through fights. If such a “newly acquired” female has a young, the male will kill the young and then mate with the female to ensure that her future youngs are his own. The females highest in the hierarchy stay closest to the dominant male, and mutual grooming most often occurs between him and the highest-ranking females.

It is clear when the females are in heat. Their buttocks swell and redden, sending a clear visual signal to the male. You have probably also seen this if you have passed their facility in the Primate House at the zoo. However, the females are also able to “fake” this visualization. In this way, they can attract positive attention from the male and improve their position in the hierarchy.

A female baboon usually gives birth to one young at a time. When very small, the young sits close to the mother and is initially carried around on either her stomach or back. When the youngs gets bigger, they begin to explore on their own. However, the females are often seen holding on to their youngs tail – an effective way of keeping track of where the young is.