Tragelaphus sylvaticus (Sparrman, 1780)

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 : 601-602

25.

Cape Bushbuck

Tragelaphus sylvaticus

French: Guib sylvain / German: Sudliche Schirrantilope / Spanish: Bushbuck meridional

Taxonomy. Antilope sylvatica Sparrman, 1780 ,

Groot Vatersbosch District, southern Cape, Africa.

The Cape Bushbuck was formerly considered a subspecies of T. scriptus , but it is diagnostically different from other bushbucks. Variation in coat color and patterning among populations of Cape Bushbuck suggest some gene flow with the Nile Bushbuck ( T. bor ). Because of the pale color of Cape Bushbuck from Mount Elgon (comparable to the Ethiopian Highlands Bushbuck), they may be a separate species, but additional specimens need to be evaluated. Synonyms of the Cape Bushbuck include delamerer , roualeynei , massaicus , dama , haywoodi , meruensis , tjaederi , brunneus , eldomae , dianae , simplex , sassae , makalae , barkeri , and heterochrous . Monotypic.

Distribution. Extreme S Sudan, E Uganda, W Kenya, E Rwanda, E Burundi, Tanzania, S Malawi, Mozambique, C & S Zimbabwe, E Botswana, Swaziland, and E & S South Africa.

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 sexually dimorphic, and the weight of male bushbucks, in general, is about 160% of that of females. Bushbucks are the smallest tragelaphines; they have large ears and eyes and a rather round, crested back. Their hindquarters tend to be higher and more robust than their forequarters. Cape Bushbucks have the greatest variation in color and patterning, some of which may represent gene flow between adjoining species. Older male Cape Bushbucks are deep brown to blackish-brown, with grayish sides and more chestnut above. Younger males are more red-brown than older males. The forehead of the Cape Bushbuck is blackbrown, and the nose is black, with two white suborbital spots. Cape Bushbucks have a white mark on the throat, and white spots, usually indistinct, occur on the face and haunches. In adult males, there is little or no trace of transverse or longitudinal stripes. Females are dark yellow-brown to reddish, tending to be paler on the shoulders and upper forelegs; they often have distinct traces of stripes. Males from Mount Elgon tend to be more of a dark red-brown; both sexes have almost no white except for some haunch spots. However, the color of some individuals from Mount Elgon can be very similar to the paler color of the Ethiopian Highlands Bushbuck. Cape Bushbucks from western Uganda and eastern DR Congo also tend to be paler, with clear white markings; they generally have a white longitudinal band represented by a line offlecks possibly because of some gene flow from the Nile Bushbuck. This also may be the case for the type originally named sassae, which is ocher-brown with a hint of rufous, and faint but distinct white stripes. Inguinal glands occur ahead of the mammae, but there are no false hoof glands. The tail is relatively short, long-haired, and bushy, with the dorsal color the same as the back. The underside is white underneath, and usually the tip is black. Only males have keeled horns, which are nearly straight, with generally only one or slightly more twists. Horns become apparent at about six months of age. The average length of the horns of the Cape Bushbuck is 29-5 cm and the average total length of the skull is about 24-3 cm. Dental formulais10/3,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 cryptically blend into their surroundings, and preference for forest and forest edge, they are difficult to observe and census. Cape Bushbucks used six different habitat types in the coastal dune Woody Cape Nature Reserve, South Africa. Most of their time was spent in three of these: they spent 38:6% of their time in river scrub, 21:2% in restored Acacia thickets, and 15-5% in dune thickets. According to Y. Moodley and M. W. Bruford, the Knysa—Amatole Montane Forest, KwaZulu-Cape Coastal Forest Mosaic, Maputaland—Pondoland Brushland and Thicket, Albany Thicket, and Nama Karoo ecoregions of southern Africa are occupied exclusively by the Cape Bushbuck haplogroup.

Food and Feeding. Throughout the year, Cape Bushbucks in Woody Cape Nature Reserve, South Africa, ate 23 dicotyledonous species (70-98% ofthe diet) and only three monocotyledons, which were consumed more in the winter than summer. The shrub Lycium afrum occurred in the diet every month of the year, from a low of 9% ofthe diet in June to 33% in August (based on fecal analysis), but on average, the shrub Schotia afra was most common in the diet. Feeding trials suggest that Cape Bushbucks prefer to obtain their forage at about head height (mean 52-5 cm), perhaps to maximize their ability to look out for predators. Unlike Chobe Bushbucks in Chobe National Park, Botswana, Cape Bushbucks in Nairobi National Park, Kenya regularly associated with Common Impalas ( Aepyceros melampus). They also associated with Olive Baboons (Papio anubis). Both associations were thought to more related to mutual detection of danger than feeding. Cape Bushbucks have been tamed for captive feeding trials.

Breeding. Bushbucks have been described as the most socially primitive of the tragelaphines and are typically thought of as non-terrritorial polygynous breeders. In Nairobi National Park, Kenya, adult males defended their association with an estrous female but were not territorial. Encounters between males often involve intimidation-type lateral displays featuring arched backs with dorsal crest erected, tail extended, and head up with ears lowered; sometimes males intermittently prance on their hindlegs. Low-intensity fighting between males occurs during chance encounters. Serious fighting, usually near females, involves clashes, locked horns with heads low to the ground, and frequent attempts to gore the flanks of an opponent. Males are physiologically mature at 12-15 months old, but unlikely to outcompete fully mature males for estrous females. Females breed for the first time at about one year of age; gestation is about six months. Births occur throughout the year in the Central Rift Valley Province, Kenya, with a slight tendency to be concentrated around rainy periods in April-May and October-November.

Activity patterns. There islittle 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, either alone or in mother—offspring pairs.

Movements, Home range and Social organization. As with the other species of bushbuck, Cape Bushbucks do not range over a wide area. Very small home ranges of 2-5 ha for females and 5 ha for males were noted in Nairobi National Park, Kenya; subadult males occupied larger home ranges of 20 ha. The density was high at 30-1 ind/km?*. Cape Bushbucks there were said to aggregate in “loose family groups” near forest edges, dams, and river pools, but mostly they were observed alone (53-7% of about 399 observations), or as mother—offspring pairs (14:5%). In Valley Bushveld in KwaZulu, South Africa, the summer home ranges of male Cape Bushbucks were significantly larger (25-2—43-3 ha) than those of females (6-3-18-8 ha), but there were no obvious differences between subadult and adults. Home ranges in Valley Bushveld were not exclusive, but individual males and females confined much of their activity to small core areas; they used 12 to 17% of their home ranges 50% of the time. Although not aggressive to one another, regular social interactions among bushbucks are largely confined to mothers and their offspring and male—females during rut. In mixed ungulate assemblages in Lake Manyara National Park, northern Tanzania, Eastern Coastal Bushbucks are among the least common species, particularly relative to biomass (0-3 kg/ha).

Status and Conservation. Classified as Least Concern on The IUCN Red List (under 1. scriptus ), which does not differentiate the eight species identified here. In the late 1990s, numbers of bushbucks range-wide were 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. Some localized populations have decreased because of excessive illegal harvest, destruction of native habitats as human populations and livestock numbers have increased, and increased aridity. Extinct in Lesotho. Generally, however, because bushbucks are non-herding and secretive by nature, with a cryptic coat pattern and a tendency to freeze and blend in with their surroundings when faced with danger, they can coexist with humans. Bushbucks also show flexibility in being able to become nocturnal where humans are active. The Cape Bushbuck has the greatest north-south range of any of the bushbuck species, and likely benefits from the great variety of conservation efforts and protected areas found in the countries throughoutits range.

Bibliography. Allsopp (1971, 1978), Ansell (1972), Bro-Jorgensen (2008), Coates & Downs (2005), East (1999), Estes (1991a, 1991b), Groves & Grubb (2011), Haschik & Kerley (1996, 1997), IUCN/SSC Antelope Specialist Group (2009), Kingdon (1982, 1997), Lydekker & Blaine (1914), Macleod et al. (1996), Moodley & Bruford (2007), Moodley et al. (2009), Nowak (1999), Olson et al. (2001), Walther (1990a), Wilson & Kerley (2003), Wronski & Moodley (2009).

Figures

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

Distribution. Extreme S Sudan , E Uganda , W Kenya , E Rwanda , E Burundi , Tanzania , S Malawi , Mozambique , C & S Zimbabwe , E Botswana , Swaziland , and E & S South Africa .