Bale Mountains vervet  (Chlorocebus djamdjamensis)

The Bale Mountains vervet is classified as Vulnerable (VU) on the IUCN Red List (1) and is listed on Appendix II of CITES (2).

The Bale Mountains vervet (Chlorocebus djamdjamensis) is one of Africa’s least known primates, and its behaviour and ecology remain somewhat of a mystery to scientists (3). The Bale Mountains vervet is a short-tailed, medium-sized savanna monkey with long, thick, dark brown fur on its upperparts, and a white underside.  This species has dark grey hands and feet, and a black-skinned face with a white beard and a faint white fur band on its brow (4).

All species of vervet are sexually dimorphic; the male is slightly larger than the female, and has brightly coloured genitals. Young are born with dark natal fur and pink facial skin, which gradually turns to the adult colouration in the first few months after birth (4).

The Bale Mountains vervet is endemic to the highlands of Ethiopia. Its range is restricted to the Bale Mountains and Hagere Selam region (3).

The Bale Mountains vervet appears to almost exclusively inhabit bamboo forests in the Bale Mountains Massif (1) (3). The Bale Mountains vervet is found at high elevations of up to 3,000 metres (1) and is mainly arboreal, being rarely seen on the ground (3).

The Bale Mountains vervet is diurnal and spends most of its time feeding. The seasonal availability of food means that this species varies its diet during the year, mainly feeding on fruit in the dry season, and bamboo shoots and roots in the wet season. The Bale Mountains vervet also feeds on young bamboo leaves, flowers and insects (3).   

The Bale Mountains vervet usually lives in large, mixed groups of between 15 and 30 members (3). Typically, vervet groups have more females than males, and a clear dominance hierarchy determines the rank of each member of the group (3) (4). Groups are mainly made up of related females, that remain in their natal area, and unrelated sexually mature males (4).

Very little is known about the reproductive biology of the Bale Mountains vervet; however, females in the Chlorocebus genus are usually sexually mature at four years of age. The gestation period is usually between 163 and 165 days, and females give birth during the wet season to a single offspring (3) (4).

With such specific ecological requirements, the Bale Mountains vervet is most threatened by habitat loss and degradation (1) (3). Expanding human populations, conversion of land for agriculture, forest fires and logging are all reducing the available bamboo forests on which the Bale Mountains vervet depends (1).

As with other vervet species, persecution by local farmers may also pose a threat, as the Bale Mountains vervet is considered a pest in many parts of its range and may feed on agricultural crops (1) (3).

The Bale Mountains vervet is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species is carefully controlled (2). This species is also on Class B of the African Convention on the Conservation of Nature and Natural Resources, meaning that it is protected, and may only be hunted or captured with special authorisation (1) (5).

The future survival of the Bale Mountains vervet depends on effective management and conservation of the bamboo forests in which it occurs (3). Further research into the Bale Mountains vervet is needed to determine the distribution and population status of this species in order to develop effective long term conservation plans (1) (3).

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn more about vervet ecology and conservation see:

• Primate Info Net - Vervet species:
  http://pin.primate.wisc.edu/factsheets/entry/vervet