Pennant's red colobus  (Piliocolobus pennantii)

Like other red colobus, Pennant's red colobus has a typically small head, long back and round belly. The limbs are very long and the elongated fingers are aligned to form a powerful hook, well adapted to gripping branches. As with other African colobus, no thumb exists, only a small remnant bump (5). Colouration varies with the subspecies but is generally blackish-red on the crown, dark brown on the back, feet and tail, and fawn coloured on the rump, forearms and legs (6). Hair on the forehead is characteristically parted down the centre (5). Taxonomic relationships, both within this species as well as with other red colobus, are widely debated by experts and require clarification.

Found only in a few small areas in Central West Africa (5). The Bioko red colobus (P. p. pennantii) is found on Bioko Island, Equatorial Guinea, Bouvier's red colobus (P. p. bouvieri) in east-central Democratic Republic of Congo, and the Niger delta red colobus (P. p. epieni) in southern Nigeria (2) (8).

Primary and secondary rainforest, as well as marsh forest (2) (3) (6).

Little is known about the specific behaviour of Pennant's red colobus, but much can be inferred from what is known about red colobus species generally (5). Red colobus typically live in large troops of 12 to 82 individuals (7), a single troop residing in a territory of 25 to 150 hectares (5). Sovereignty over the territory is signalled via a variety of barks and chirps given by all members (5). Like other red colobus, Pennant's red colobus' groups are multi-male and multi female, usually with around twice as many females (6). Females tend to remain with the same group throughout their lives, while males may move from group to group (5). Little is known about the reproductive biology of Pennant's red colobus.

Red colobus are arboreal, often leaping across wide gaps by using the elasticity of a branch to propel themselves between trees (5). The diet consists of leaves, fruit, seeds and flowers (3) (5). Colobines are the only monkeys with chambered stomachs specially adapted to help digest tough leaf material (7).

The red colobus monkeys of Central West Africa are probably more threatened than any other taxonomic group of primates in Africa. All the subspecies of Pennant's red colobus are close to extinction, with very restricted ranges and small numbers as a result of extensive habitat loss and intensive hunting (8). Their loud vocalisations and slow movement make red colobus monkeys easy targets for hunters (5). Bouvier's red colobus (P. p. bouvieri) has not been observed alive by scientists in at least 20 years, raising concerns that it may already be extinct (1). The Bioko red colobus (P. p. pennantii) probably has the most restricted range of the other subspecies, found only in the southwest of Bioko Island, which is approximately just 2,000 km² (1). Here it is threatened by commercial bushmeat hunting and ongoing habitat destruction (1) (8).

Although protected areas do exist within the range of Pennant's red colobus, none of those in which any of the subspecies occur are particularly well protected. It has therefore been recommended that a priority for the conservation of this species must be to rigorously protect all those populations that are known to still exist, as well as to undertake field surveys to better understand current distributions and abundance of the subspecies (8). Indeed, one of Africa's highest primate conservation priorities is to create a protected area on Bioko Island (2). A survey is desperately needed for Bouvier's red colobus (P. p. bouvieri) to establish whether a population still survives, although this may be problematic in the marsh forest environment of the region it has historically occupied (1). Major international conservation organisations need to work closely with national protected area authorities to help safeguard this rare and little understood red colobus species. For Bouvier's red colobus (P. p. bouvieri), however, it may already be too late (8).

For further information on Pennant's red colobus see:

Bioko Biodiversity Protection Programme:
http://www.bioko.org

Primates in Peril: The World's 25 Most Endangered Primates 2006 – 2008:
http://www.primate-sg.org/PDF/Primates.in.Peril.2006-2008.pdf

Authenticated (28/11/2005) by Matt Richardson, independent primatologist and writer.