Tragelaphus scriptus (Pallas, 1766)

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 : 597

18.

Western Bushbuck

Tragelaphus scriptus

French: Guib harnaché / German: Senegal-Schirrantilope / Spanish: Bushbuck septentrional

Other common names: Harnessed Antelope

Taxonomy. Antilope scripta Pallas, 1766 ,

Senegal.

Because of the great variation in color and patterning of the coat of bushbucks and their wide geographical range in 40 sub-Saharan African countries (the most extensive of all African bovids), at least 40 subspecies of T. scriptus have been described. Recent molecular and morphometric analyses of bushbucks from across their wide range have identified two sister clades, or groups, “scriptus” (here including T. scriptus , T. phaleratus , T. bor , and T. decula ) and “sylvaticus” (here including T. meneliki , T. fasciatus , T. ornatus , and T. sylvaticus ). According to Y. Moodley and M. W. Bruford, the fossil record suggests that bushbucks originated in north-eastern Africa 3-9 million years ago, when the area was thickly forested, unlike today, and that the two groups diverged more than 2-5-2-7 million years ago, one spreading eventually to the western coast of Africa and the other spreading eventually to extreme southern Africa. Additional research is required, however, to describe these species fully, geographically and ecologically, and to ascertain if more species should be recognized. The mtDNA assessments unite the Western Bushbuck from far western Africa, and the support value for this clade is 99%. Synonyms of scriptus include leucophaeus , gratus , and obscurus . Monotypic.

Distribution. Extreme S Mauritania, S Senegal, extreme SW Mali, Gambia, Guinea-Bissau, Guinea, Sierra Leone, and W Liberia. The exact location of the boundary between the Western Bushbuck and the Central Bushbuck ( T. phaleratus ) is unclear and needs additional investigation.

Descriptive notes. Head-body 117-145 cm (males) and 114-132 cm (females), tail 19-24 cm, shoulder height 64-100 cm (males) and 61-85 cm (females); weight 40-80 kg (males) and 24-60 kg (females). These measurements are general for the bushbuck group and should be considered provisional until further information is available for individual species. Tragelaphines are typified by their sexual dimorphism. The weight of male bushbucks, in general, is about 160% of that of females. Bushbucks are the smallest tragelaphines, with large ears and eyes and a rather round, crested back. Their hindquarters tend to be higher and more robust than their forequarters. The male Western Bushbuck is a rich dark rufous with a blackish suffusion; the female is paler. The pelage of both sexes is fairly long and marked with 3-10 distinct transverse white stripes, an upper and a lower white longitudinal flank band, and a circle of white haunch spots. The dorsal crest of both sexes is white. The upperparts of the limbs are blackish, and their inner sides are white. The forelimbs often have a black line down the front. The underparts are black. There are inguinal glands anterior to the mammae, but no false hoof glands. The tail is relatively short, long-haired, and bushy; the outside of the tail is the same color as the back, and the underside is white. The tail tip is usually black. Only males have keeled horns. The horns are nearly straight, with generally only one or slightly more twists. The average length of the horns of male Western Bushbuck is about 23 cm. Average total length of the skull is 23-7 cm. Dental formulais 10/3, C0/1,P 3/3, M 3/3 (x2) = 32. Diploid numbers for the bushbuck group are 33 for males and 34 for females.

Habitat. As a group, bushbucks are the most ubiquitous hoofed mammals in Africa, but because of their relatively solitary nature (particularly males), relatively small size, tendency to freeze and blend into their surroundings, and preference for forest and forest edge, they are difficult to observe and census. According to Moodley and Bruford, the West Guinea Forest—Savanna mosaic ecoregion of West Africa is occupied exclusively by the Western Bushbuck haplogroup. They are often found near free water, which may be as much because their preferred forested habitats thrive near water as a physiological need.

Food and Feeding. There is no specific information available for this species, but probably, like other bushbuck species it eats a variety of shrubs, legumes, and other herbaceous plants as well as new-growth of grasses. Elsewhere, bushbucks are fond of the fruits of various trees and can be observed feeding on fallen fruits under trees in which baboons and other monkeys are foraging. In various locations, bushbucks are agricultural pests eating various crops by night.

Breeding. Bushbucks have been described as the most socially primitive of the tragelaphines and are typically thought of as non-terrritorial polygynous breeders (but see the Nile Bushbuck for the most thorough studies of breeding behavior).

Activity patterns. There is little specific information available for this species, but activity patterns are probably comparable to the general bushbuck pattern of being crepuscular and nocturnal and spending much of the day resting/ruminating in forest cover, often alone or in mother/offspring pairs.

Movements, Home range and Social organization. There is little specific information available for this species, but it is probably comparable to other bushbuck species (see the Nile Bushbuck for the most through studies of these characteristics). Bushbucks do not range over a wide area. Home ranges are not exclusive, but individuals do have their own, apparently exclusive, places to rest during the day. Although not aggressive to one another, regular social interactions among bushbucks are largely confined to mother—offspring pairs and male—females during rut.

Status and Conservation. Classified as Least Concern on The IUCN Red List (under T. scriptus ), which does not differentiate the eight species identified here. In the late 1990s, the number of bushbucks range-wide was estimated conservatively at over 1-34 million, and they were not particularly dependent on conservation initiatives, such as protected areas, if adequate cover and water were available. Bushbuck populations are considered stable range-wide. In localized areas, some populations of bushbucks have decreased because of excessive illegal harvest, destruction of native habitats as human and livestock numbers have increased, and increased aridity. Generally, however, bushbucks can do well in areas of human habitation because of their secretive nature, non-herding tendencies, cryptic coat patterning and tendency to freeze and blend into their surroundings when faced with danger, and ability to adopt a nocturnal pattern in areas of human activity. In the late 1990s, populations of Western Bushbucks in Senegal were estimated at more than 50,000 in protected areas, but facing pressure from habitat loss and livestock grazing elsewhere in western Africa.

Bibliography. Ansell (1972), Bro-Jorgensen (2008), East (1999), Estes (1991a, 1991b), Groves & Grubb (2011), Kingdon (1982, 1997), Lydekker & Blaine (1914), Moodley & Bruford (2007), Moodley et al. (2009), Nowak (1999), Olson et al. (2001), Rubes et al. (2008), Walther (1990a), Wronski & Moodley (2009).

Figures

14. Saola (Pseudoryx nghetinhensis), 16. Chowsingha (Tetracerus quadricornis), 17. Nyala (Nyala angasii)

Distribution. Extreme S Mauritania , S Senegal , extreme SW Mali , Gambia , Guinea-Bissau , Guinea , Sierra Leone , and W Liberia . The exact location of the boundary between the Western Bushbuck and the Central Bushbuck ( T. phaleratus ) is unclear and needs additional investigation.