The olive baboon (Papio anubis), also called the Anubis baboon, is a member of the family Cercopithecidae (Old World monkeys). The species is the most widely ranging of all baboons: it is found in 25 countries throughout Africa, extending from Mali eastward to Ethiopia and Tanzania. Isolated populations are also found in some mountainous regions of the Sahara. It inhabits savannahs, steppes, and forests.
Communication
Olive baboons communicate with various vocalizations and facial expressions. Throughout the day, baboons of all ages emit the "basic grunt".[25] In addition, other calls given by adults include the "roargrunt", "cough-bark", and "cough geck". The latter two are made when unknown humans or low-flying birds are sighted, and the former is made by adult males displaying to each other. A "wa-hoo" call is made responding predators, neighboring groups at night and during stressful situations.[25] Other vocalizations include "broken grunting" (low volume, quick series of grunts made during relatively calm aggressive encounters), "pant-grunts" (made when aggressive encounters escalate), "shrill barks" (loud calls given when potential threats appear suddenly), and "screams" (continuous sounds of high-pitch responding to strong emotions). The most common facial expression of the olive baboon is "lipsmacking" which is made is associated with a number of behaviors. Lipsmacking as well as "tongue protrusion", "jaw-clapping", "ear flattening", "eyes narrowed", and "head shaking" used when baboon are greeting each other and are sometimes made with a "rear present". Staring , "eyebrow raising", "yawning", and "molar grinding", are used to threaten other baboons.[15] A submissive baboon will respond with displays like the "rigid crouch", "tail erect", and "fear grin".
Diet
Foraging in Kenya
One major reason for its widespread success is that the olive baboon is not bound to a specific food source.[4] It is omnivorous, finding nutrition in almost any environment, and able to adapt with different foraging tactics.[26] For instance, the olive baboon in grassland goes about finding food differently than one in a forest.[4] It is also worth noting that the baboon will forage on all levels of an environment: above and beneath the ground and in the canopy of forests.[26] Most animals will only look for food at one level; an arboreal species for instance, such as a lemur, will not look for food on the ground. The olive baboon will search as wide an area as it can, and it will eat virtually everything it finds.
Virtually everything includes a large variety of plants, and invertebrates and small mammals as well as birds.The olive baboon will eat leaves, grass, roots, bark, flowers, fruit, lichens, tubers, seeds, mushrooms, corms, and rhizomes.Corms and rhizomes are especially important in times of drought, because grass loses a great deal of its nutritional value. In dry, arid regions, such as the northeastern deserts, small invertebrates like insects, spiders, and scorpions fill out its diet.
The olive baboon will also hunt prey, from small rodents and hares to foxes and other primates. Its limit is usually small antelope, such as Thomson's Gazelle and also, rarely, sheep, goats, and live chicken, which amount to 33.5% of its food from hunting.[4] Hunting is usually a group activity, with both males and females participating. Interestingly, there is evidence that this systematic predation was developed recently. In a field study, such behavior was observed as starting with the males of one troop and spreading through all ages and sexes.
Observations suggest that in Eritrea the olive baboon has formed a symbiotic relationship with that country's endangered elephant population. The baboons use the water holes dug by the elephants, while the elephants use the tree-top baboons as an early warning system.
