Species: Colobus guereza
Common Name: Black and white colobus, guereza
The black and white colobus resides in most parts of sub-Saharan Africa. It can be found in a wide variety of forest, woodland, and wooded grassland habitats.
Like most colobines, the black and white colobus is characterized sharp high cusped molars, narrow incisors, short snouts, narrow nasal openings, broad interorbital area, deep mandibles, sacculated stomachs, long legs and long tails (in the black and white colobus the long tail has a spectacular white tuft at the end).
The thumb is reduced to a tubercle (see definition 3) and ischial callosities (there seems to be some dispute about this Ankel-Simons says no, Fleagle, and Nowak say yes, as does the ADW) are present. The nose often hangs out over the top lip and they have a large larynx – which makes them quite vocal and loud (though not as loud as Howler monkeys). They are fairly good leapers and in areas with sparse tree cover they spend quite a bit of time on the ground. They are the largest of the African colobines and are sexually dimorphic (some dispute about this as well, Ankel-Simons and the ADW say very little, Fleagle says considerable). They live in small bands of one male and 3-4 females, plus young. Male offspring are forced to migrate upon obtaining adulthood, consequently, there seems to be some evidence for infanticide when males take over a new group. There is also some evidence for “aunting” behavior among females. The young are born completely white.
They are folivorous, but occasionally eat flowers and fruit. They also tend to focus on only a few tree species.
Since there seems to be some dispute over whether the black and white colobus has ischial callosities I am assigning some homework. Those of you who live close enough to a Zoo please go and, if they have the black and white colobus, take pictures of its butt in enough detail that we can tell if it has ischial callosities. I will publish the best of those pictures in a future post – giving full credit to the photographer(s)…