Philantomba melanorhea (Gray, 1846)

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 713-714

234.

Bioko Blue Duiker

Philantomba melanorhea

French: Céphalophe de Bioko / German: Bioko-Blauducker / Spanish: Duiker azul de Fernando Poo

Taxonomy. Cephalophus melanorheus Gray, 1846 ,

Fernando Po.

Formerly considered a subspecies of P. monticola . Historically, the Bioko Blue Duiker also encompassed the mainland populations of P. aequatorialis and P. anchietae . Monotypic.

Distribution. Endemic to Bioko I, Equatorial Guinea.

Descriptive notes. Head-body 50-59 cm, tail 6-10 cm, ear 4.3-5. 3 cm; weight 3.9-5 kg. No specific body weights have been made apart from average weights (collected from animals studied in bushmeat markets); based on skull characteristics, general size is smaller than the Western Blue Duiker (P. congica). Pelage is long and thick; the overall color is gray-brown, with a distinctly dark dorsal surface (approaching black). The flanks are pinkish-gray and the underparts whitish. The black of the dorsum spreads laterally at the tail base to form a horizontal band. This band blends gradually into the brown pelage dorsally and cranially, but forms a line of sharp contrast with the pale hips, which may be almost white at the line of demarcation. The dorsal surface of the tail is black and its underside is white. The front legs and lower hindlegs are the same color as the body. Reversal of hair tracts on the nape of the neck occurs in 75% of specimens. The face is similar in color to the body; there is minimal contrast between cheeks and mid-facial region. Horns are present in both sexes. Despite the small body size, the horns are relatively long, averaging 4-31 cm in males and 3-35 cm in females. Dental formula is 10/3, C 0/1, P 5/3. M 3/38 (2) = 332.

Habitat. Bioko Blue Duikers inhabit a wide variety of forest habitats across Bioko Island, including primary and secondary forest and forest edges. The distribution encompasses elevations up to 2000 m. This species currently occupies 70-90% of Bioko Island, and it is often found nearvillages. Average density across the island is 22-6 ind/km?®.

Food and Feeding. There is no specific information available for this species, but presumably frugivorous like other Central African Philantomba duikers.

Breeding. There is no specific information available for this species, but likely similar to the Western Blue Duiker on the adjacent mainland.

Activity patterns. There is no specific information available for this species, but presumably diurnal.

Movements, Home range and Social organization. There is very little specific information available for this species. Field sightings are typically of individuals or pairs. Bioko Blue Duikers are easily recognized in the field by the flashes of white from the underside of the tail; this duiker rapidly flicks its tail up and down while moving and foraging.

Status and Conservation. CITES Appendix II (under P. monticola ). Classified as Least Concern on The IUCN Red List (combined with the other nine blue duiker species within the P. monticola complex). Locally common in protected areas (especially in Pico Basilé and Gran Caldera de Luba), Bioko Blue Duikers are intensively hunted for meat, accounting for an average of 29-33% ofcarcasses in Bioko bushmeat markets. It is the second most common species hunted after Forest Giant Pouched Rat (Cricetomys emini). Overhunting is the principal threat to survival.

Bibliography. Albrechtsen et al. (2006), Butynski et al. (2001), East (1999), Fa et al. (1995), Grubb & Groves (2001), IUCN/SSC Antelope Specialist Group (2008as), Lydekker (1914).

Figures

233. Western Blue Duiker (Philantomba congica), 234. Bioko Blue Duiker (Philantomba melanorhea), 235. Eastern Blue Duiker (Philantomba aequatorialis), 236. Mountain Blue Duiker (Philantomba lugens), 237. Simpson’s Blue Duiker (Philantomba simpsoni), 238. Malawi Blue Duiker (Philantomba hecki), 239. Zimbabwe Blue Duiker (Philantomba bicolor), 240. Cape Blue Duiker (Philantomba monticola), 241. Angolan Blue Duiker (Philantomba anchietae), 242. Zambian Blue Duiker (Philantomba defries)

Distribution. Endemic to Bioko I, Equatorial Guinea .