You may have noticed that despite the heavy favouring of mammals in this blog, there is a lack of primate entries. There are two reasons for this: a) I know almost nothing about primates, and b) I really don’t find them that cute or likeable. But still, I’m trying to cover all sorts of species in this blog, so I guess its time for a primate (I’m not counting the Aye-aye as a real primate here just because it’s so weird).
So today’s post is a strangely named animal, the hamadryas baboon. I have no idea why it’s called ‘hamadryas’, but it seems like a pretty weird name to me. Hamadryas baboons live in the Northeastern part of Africa (just above the ‘horn’) and in the Southwest corner of Yemen. They live in grassy meadows, steppe, plains, and basically anywhere where there isn’t a lot of natural predators. In these relatively arid lands, the baboons have to rely on specific watering holes in the dry season, and their range is limited by the location of these. Hamadryas baboons are foragers, eating whatever they can find, including fruits, eggs, grasses, insects and small vertebrates. They can live off of relatively low quality diets, which allows them to live in semi-arid regions where natural predators are low.
The social organization of hamadryas baboons is, like many primates, quite complex. The basic structure is the one male unit (OMU), which consists of a single dominant male and from one to nine females. The male has exclusive mating rights to these females, and he aggressively keeps them from interacting with males from other OMUs. A clan is formed from two or three OMUs, and is usually comprised of related males. Clans generally travel and forage together, for greater security. Two to three bands join together to form a band. Bands sleep together and gather at watering holes in the middle of the day. In the morning before the baboons leave to forage, the OMU males coordinate which watering hole they will meet at. To do this, a somewhat democratic process is followed. A male will take a few steps in the direction of the watering hole he would like to go to, and if another male agrees, they will also walk in that direction. Males who disagree will walk in the direction of another watering hole. When a majority is reached, the band splits up and forages separately, meeting at the decided upon watering hole in the middle of the day.
The membership of bands of hamadryas baboons is very stable; although males and females often leave their OMUs or clans when they are of age, they rarely disperse outside of their band. Troops are the fourth level of hamadryas baboon society; these are formed from multiple bands. They form around sleeping areas and don’t seem to have much social significance, instead being an artifact of the limited suitable sleeping places in the baboon’s habitat.
OMUs can be formed in one of two ways. First, many OMUs have a ‘follower male’, who is often related to the OMU leader. This male does not mate with the females in his OMU and waits until he is strong enough to challenge the OMU leader. The second strategy involves a male adopting a juvenile female. He feeds and takes care of the female, allowing her to ride on his back and grooming her. When she is sexually mature, he breeds with her, and this attracts other females to his newly formed OMU. After all, what kind of baboon would want to go hang out with a loser male who can’t even get a mate?
So now I know something about baboons, and hopefully you do too. The complex social structure of many primate species is very interesting, and hopefully I can get over my dislike of primates and blog about more of them. We’ll see!