PHOTO: CHARLES SHARP/SHARP PHOTOGRAPHY
Although its name suggests a gentle character, female blue monkeys are forced to protect their young against murderous members of their own species.The blue monkey (Cercopithecus mitis stuhlmanni) lives in groups of around ten individuals, consisting of a dominant male, several females, and their offspring. Female individuals typically remain in their natal group for their entire lives. Only when a group splits do female monkeys get the rare opportunity to reshape their social environment.
American scientists followed five group splits in the Kakamega Forest in Kenya and found that close female friends often choose to join the same new group together. Social bonds appear to play a greater role in this than kinship (Proceedings of the Royal Society B, 25 September). Females with young or unborn offspring almost always opt for the group in which the familiar male is the leader. This is less a sign of affection for their own mate than a fear of the unknown – and a well-founded fear at that, since new male blue monkeys frequently resort to infanticide, killing another male’s offspring in order to reproduce more quickly with the females in the group.
Questionable
The scientist who named this primate species was evidently unaware of this grim habit. The genus name – derived from the Ancient Greek κέρκος (kerkos), meaning ‘tail’, and πίθηκος (píthēkos), meaning ‘monkey’ – is beyond dispute: the blue monkey’s tail is longer than the rest of its body. The specific epithet mitis, however, which comes from Latin and translates as mild or gentle, is rather questionable. An homage to the German explorer Franz Stuhlmann (1863–1928), who described numerous animals in East Africa, gives the blue monkey its subspecific designation stuhlmanni.
In English, this animal is likewise known by the somewhat misleading common name gentle monkey. The Dutch name – diadeemmeerkat, meaning ‘diadem monkey’ – refers to the striking band of pale hair above the eyes, and wisely makes no comment on the personality of this primate species.