Cephalophus callipygus Peters 1876

254. Peters’s Duiker Cephalophus callipygus French: Céphalophe de Peters / German: Peters-Ducker / Spanish: Duiker de Peters Taxonomy. Cephalophus callipygus Peters, 1876, Gabon. Closely related to Weyns’s Duiker (C. weynsi), which was formerly classified as a subspecies of Peters’s Duiker. Monotypic. Distribution. S Cameroon E to SW Central African Republic and Republic of the Congo, S to Equatorial Guinea and Gabon; bounded to the E by the Congo and Ubangirivers. Descriptive notes. Head-body 101-2 135 cm, tail 13-16. 5 cm, shoulder height 50-576 cm; weight 17.2-26. 9 kg. Females are generally larger than males. General color is reddish-brown but can range from tawny to a rich russet or even dark brown. Central African populations tend to be darker than western forms. A thin black dorsal line begins between the shoulders and runs along the spine to the rump, typically expanding onto the haunches and hindlegs so that the entire rump (including the tail) is dark. The legs, shoulders, neck, and face are dark in some individuals. The belly is paler than the rest of the body. The head lacks distinct markings, except for two white spots (0.8-1 cm in diameter) just above and behind each eye. The forehead is reddish-brown, and a rich russet-colored tuft of hair is present on the top of the head. The ears are whitish inside, with a black and white band at the edges. Horns, present in both sexes, are short, pointed, and in line with the face. They are 6.2-9. 1 cm long in males, 4.5-8 cm long in females. The skull is very heavily reinforced at the forehead, with the frontal bone in males up to 1-8 cm thick. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x2) = 32. Habitat. Moist lowland equatorial forests. Peters’s Duiker avoids outlying riverine strips and gallery forests. Dense undergrowth is needed for shelter; individuals flee to dense thickets if disturbed. This species therefore does well in forests regenerating after logging. Density estimates from line transects in the Central African Republic were 0-9 ind/km? and 0-9—4-4 ind/km?*from net encounters. Densities in other areas may be as low as 0-6 ind/km? to as high as 15-5 ind/km?*. Food and Feeding. One of the most completely frugivorous duikers. Fruit comprises, on average, 79-89-6% of the diet by dry weight based on examination of stomach contents. Other dietary components include leaves, petioles, and stems (7-9-16:2%). Flowers, fungi, and animal matter (principally insects) are found much less frequently (in fewer than 50% of animals sampled), and comprise less than 1% of the diet. Fruit consumption is lowest and leaf ingestion highest from March to May (the short rainy season). Peters’s Duikeris specialized in feeding on small fruits: 40-2% of fruits consumed are 1-2 cm in diameter, and 77-2% are 0.5-3 cm. Critical size for swallowing fruits whole is 2-3 cm. Fruits from 55 plant species have been identified in the diet; favored species include Xylopia hypolampra, Cylindropsis parvifolia, Canarium schweinfurtha, Klainedoxa gabonensis, Coelocaryon preussii, Pycnanthus angolensis, and Staudtia stipitata. Unweaned animals eat much less fruit and significantly more leaves than adults. A Peters’s Duiker in the Central African Republic was observed actively (and successfully) hunting young Hartlaub’s ducks (Pteronetta hartlaubur). Breeding. Breeds continually throughout the year, but birth peaks have been noted in May-June and December. These peaks correspond with the early months of the two dry seasons, when the quantity and quality (protein content) offruits are highest. The gestation period is estimated at 240 days, based on that for the similarly sized Eastern Bay Duiker (C. castaneus). Infants weigh approximately 3 kg at birth, and are darker in color than adults but with paler forequarters. The dorsal stripe is already apparent in neonates. Activity patterns. Strictly diurnal, risingjust before sunrise (5:15-6:00 h) and bedding down just after sunset (18:30-19:00 h). Peters’s Duiker often rests in dense thickets during the middle of the day (such rests last for an average of 51 minutes). Both thickets and more open areas may be used at night. Rumination generally occurs at night, based on piles of regurgitated fruit stones around resting areas. Neither daytime nor night-time resting areas appear to be reused. Movements, Home range and Social organization. There is an active social system and polygynous social structure. Daily movements of 2—4 km are typical. Adult females inhabit home ranges approximately 0-4 km?* the home range of one adult male was 0-36 km?*. Males are believed to be territorial. Status and Conservation. Classified as Least Concern on The IUCN Red List. The total population of this speciesis estimated at 382,000; it is widespread and locally common. Peters’s Duiker is known for dense populations that regenerate rapidly. Primary threats are hunting and habitat loss due to human settlement. Peters’s Duikeris especially affected by snare hunting. In the Central African Republic, this species accounted for 29% of all animals captured in snares and 56% of captures by weight; hunters calculate their total returns in Peters’s Duiker units. The rate of snare hunting does not appear to be sustainable for this species, even under the most optimistic of circumstances. Unless mediatory actions are taken, Peters’s Duiker could decline drastically. Bibliography. Dubost (1984), Dubost & Feer (1992), East (1999), Feer (1989a, 1995), Happold (1973), IUCN/ SSC Antelope Specialist Group (2008a), Kingdon (1997), Noss (1998a, 1998b), Walther (199a0), Wilson (1987, 2001).Published as part of Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, pp. 444-779 in Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona :Lynx Edicions on page 724, DOI: 10.5281/zenodo.651248