The endangered Pennant’s red colobus monkey Procolobus pennantii (Waterhouse, 1838) is presently regarded by the IUCN/SSC Primate Specialist Group as comprised of four subspecies, but their relationships within P. pennantii, and with other taxa of red colobus, need clarification (Groves 2001; Grubb et al. 2003). Future research may reveal that these four “subspecies” are better referred to as full species. P. pennantii takes its name from the form restricted to Bioko Island, Equatorial Guinea, P. pennantii pennantii. This endangered subspecies probably has the most restricted range of all of Bioko’s 11 primates, and is now found only in a small part of the southwest of the island, within the Gran Caldera and Southern Highlands Scientific Reserve (51,000 ha).

P. p. pennantii is threatened by bushmeat hunting, most notably since the early 1980’s when a commercial bushmeat market appeared in the town of Malabo (Butynski and Koster 1994). Hearn et al. (2006) estimated numbers killed for bushmeat at 550 and 350 in the years 2004 and 2005, respectively, and a decline of more than 40% in the population over the 20 years from 1986 to 2006. The average price paid in the Malabo market for an adult P. pennantii in 2006 was about US$42. This is well over twice as much as the cost of the readily available, high quality, whole chicken and beef at the same market. Similar high prices are paid on Bioko for all seven species of monkeys and for both species of duikers. Bushmeat on Bioko is, obviously, now a ‘luxury food’ (Hearn et al. 2006).

Probably all of the P. pennantii killed on Bioko at this time are coming from within the Gran Caldera and Southern Highlands Scientific Reserve, but small numbers may persist in the most remote and rugged parts of Bioko’s other protected area, the Pico Basile National Park (330 km²). The continued high flow of primates, duikers and other wildlife into the Malabo bushmeat market indicates that neither ‘protected area’ is receiving adequate protection from the government of Equatorial Guinea.

The other three subspecies are: the critically endangered Bouvier’s red colobus P. p. bouvieri (Rochebrune, 1887) of east-central Republic of Congo; the endangered Niger Delta red colobus P. p. epieni Grubb and Powell, 1999, of Nigeria; and the endangered Preuss’s red colobus P. p. preussi (Matschie, 1900) of southeastern Nigeria and western Cameroon (Oates 1994, 2000; Struhsaker 2005). P. p. pennantii and P. p. preussi are particularly distinct taxa in terms of their vocalizations, while the vocal repertoire of P. p. epieni most closely resembles those of the red colobus in central and eastern Africa (T. T. Struhsaker unpublished data).

To the northwest of the P. pennantii complex of subspecies occurs the critically endangered Miss Waldron’s red colobus P. badius waldroni (Hayman, 1936) of southwestern Ghana and southeastern Côte d’Ivoire (Struhsaker 1999; Oates et al. 2000; Groves 2001; Grubb et al. 2003). All five of these subspecies are today close to extinction, with very restricted ranges and small numbers as a result of intensive hunting and extensive habitat degradation and loss (Wolfheim 1983; Oates 1994, 1996; Oates et al. 2000; Struhsaker 2005; Hearn et al. 2006). Neither P. p. bouvieri nor P. b. waldroni have been observed alive by scientists for at least 25 years, raising concerns that they may be extinct (see profile for Miss Waldron’s red colobus in this report).

The red colobus monkeys of West Africa and west Central Africa are probably more threatened than any other taxonomic group of primates in Africa. This is partly due to the fact that red colobus are especially sensitive to habitat degradation and vulnerable to hunters (Oates 1996; Oates et al. 2000; Waltert et al. 2002; Struhsaker 2005). None of the few protected areas in which any of these five subspecies of red colobus occur is well protected (e.g., McGraw 1998). Of very high priority for the conservation of primate biodiversity in Africa is the need to (1) immediately undertake field surveys to determine the current distributions and abundance of these five subspecies of red colobus, and, at the same time, (2) rigorously protect all of those populations that are known to exist.

Providing adequate protection to viable populations of these five subspecies of red colobus would greatly assist the conservation of numerous sympatric threatened taxa. Among primates, these include: the mainland Preuss’s monkey Cercopithecus preussi preussi; Bioko Preuss’s monkey C. p. insularis; Bioko red-eared monkey C. erythrotis erythrotis; golden-bellied crowned monkey C. pogonias pogonias; Roloway monkey C. diana roloway; Bioko greater white-nosed monkey C. nictitans martini; Bioko black colobus Colobus satanas satanas; white-naped mangabey Cercocebus atys lunulatus; mainland drill Mandrillus leucophaeus leucophaeus; Bioko drill M. l. poensis; western chimpanzee Pan troglodytes verus; and Nigeria chimpanzee P. t. vellerosus.

If a concerted effort is to be made to save all of the diversity present within the red colobus, then the major international conservation NGOs will need to focus their efforts on this taxonomic group and work closely with national conservation NGOs and national protected area authorities. For P. p. bouvieri and P. b. waldroni, however, it may already be too late.

Thomas M. Butynski, John F. Oates, W. Scott McGraw & Thomas T. Struhsaker