Udzungwa Red Colobus

The Udzungwa red colobus lives in multi-male/multi-female groups of anything between 7 and 83 individuals, but usually of around 24 (2) (7). Those groups in highly degraded forests where food is scarce are thought to adopt a system of fission-fusion society, in which the larger troop breaks up into smaller groups to forage (7). This diurnal species (8) feeds mainly on leaves, but will also eat flowers, fruits and fungus (2) (6). The peculiar behaviour of geophagy (eating of soil) has occasionally been observed, which is thought to assist digestion in a similar way to charcoal consumption by other animals (6) (9). Udzungwa red colobus are preyed upon by crowned hawk-eagles and chimpanzees. When a predator has been spotted, these monkeys alert others in the group through a series of calls, which differ to indicate either an aerial or ground predator (2). Information is rather scant on the reproductive biology of this monkey. Males attain sexual maturity at around four and a half years of age, and females at about four, after which females are known to have a substantial pink sexual swelling during oestrous. After birth, parental care is performed solely by the mother, who carries the infant on her belly for the first three months (2).

The Udzungwa red colobus is found in four protected areas in Tanzania: Magombero Forest Reserve, Selous Game Reserve, Udzungwa Mountains National Park (2) and New Dabaga/Ulangambi Forest Reserve (NDUFR) (10). Udzungwa Mountains National Park, which holds the largest population of these monkeys, has no roads and all access is by foot, limiting potential disturbance (8). Elsewhere, however, the species occurs either on public land or in forest reserves that are not effectively protected (5). Since studies have shown that reduced habitat quality adversely affects group density, size, composition and recruitment, closed-canopy forest is considered to be crucial for the long-term survival of this endangered colobus monkey (6). Indeed, the Udzungwa Mountains contain a rich array of biodiversity, including at least 10 primate species, and as such, constitute an area of global importance for biodiversity conservation (11). Thus, protecting the forests of these mountains must be a priority not only for the Udzungwa red colobus, but for all the fauna and flora that share this diminishing habitat.

The most distinctive feature of the Udzungwa red colobus is its conspicuous crown of spiky red hair, which stands out dramatically from the black-and-white coat of the rest of the body (2). The coat is black on the monkey's upperparts, and white on its underside and inner surfaces of the limbs (2). The arms and thighs are black, but the shanks are a paler, more silvery-black (2). The short, slightly bushy tail is white below and either black or a dull yellowish-black above (2). The cheeks are white and a thick black line runs along the temple, separating the face from the bright red crown (2). Colobus means 'docked' in Greek, referring to the small remnant bump that all colobus species have in place of a thumb. However, the other fingers are elongate and aligned to form a powerful hook, well adapted to gripping branches (4). Taxonomic relationships within this species, and with other taxa of red colobus, are widely debated by experts and require clarification.

Found in primary and secondary forests of lowland riverine, semi-deciduous forest to montane, mature evergreen forest, at elevation of between 200 and 1,600 m above see level (1) (2) (6).

This species is known only from the fragmented forests of the Udzungwa Mountains in south-western Tanzania, and from a few small patches of forest in the nearby Kilombero Valley in south-central Tanzania (2) (5).

Classified as Vulnerable (VU B1+2abcde) on the IUCN Red List 2006 (1) and listed on Appendix II of CITES (3).

The Udzungwa red colobus has a limited range that continues to shrink and become increasingly fragmented (2). The species has suffered from habitat destruction and degradation due to construction of a railway within its range, combined with extensive logging, agricultural expansion, collection of firewood and charcoal production (5) (6). Habitat degradation remains a serious concern due to the impact on social groups (9). Studies have indicated that reproductive success, group size and group density are significantly reduced in small and degraded forests (5). The small forest remnants in the Kilomero Valley that lie outside of protected areas, or lack the protection they were promised, are particularly vulnerable (5). Reduced social group size increases vulnerability to predators (9) and poachers, with hunting for Udzungwa red colobus meat, considered a delicacy, posing another serious threat to the species (2).

The Udzungwa red colobus (Piliocolobus gordonorum), also known as the Uzungwa red colobus or Iringa red colobus, is a species of primate in the family Cercopithecidae. It is endemic to riverine and montane forest in the Udzungwa Mountains in Kilolo District of Iringa Region in Tanzania. It is threatened by habitat loss.