Sitatunga

Maximum longevity: 22.6 years (captivity) Observations: These animals can live up to 22.6 years in zoos (Richard Weigl 2005).

The Sitatunga, a swamp-dwelling antelope, exhibits great elongation of the hooves, which have a wide splay and naked padlike pattern. They possess unique flexibility of the joints at the feet, representing structural adaptations for walking on boggy and marshy ground.

Coloration varies geographically and individually. Males are gray-brown to chocolate-brown, females are brown to bright chestnut, and calves are bright rufous-red, woolly coated, spotted, and striped. Adults are long coated and have characteristic whiteish marks on the face, ears, cheeks, body, legs, and feet.

Males are considerably larger than females (100 cm tall vs. 75-90 cm tall). Males possess horns ranging in length from 508-924 mm. Horns are characterized by two twists and are ivory tipped.

Range mass: 50 to 125 kg.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; sexes colored or patterned differently

Average lifespan
Status: captivity: 22.6 years.

The sitatunga is semiaquatic, and so specialized that it occurs only in swamps or permanent marshes. Partial to papyrus and phragmites within swamps, it may also occur in wetlands dominated by bullrushes, reeds, and sedges. They frequent the deepest parts of the swamp. (Estes, 1991; Nowak, 1991)

Aquatic Biomes: lakes and ponds

Center of distribution is the southwestern African rainforest and the wetter regions of the southern savanna. Specifically Gambia to S.W. Ethiopia, south to Angola, Namibia, N.W. Botswana. (Estes, 1991; Honacki et al., 1982)

Biogeographic Regions: ethiopian (Native )

Alchornea cordifolia, common around Lake Victoria, provides a favorite browse for sitatunga. Foraging takes place in both dry land and swamp. Sitatunga select plants in the flowering stage. They often emerge at night from swamplands to graze on nearby dry land, as well as in adjacent forests where they browse on foliage and creepers. Feeding activity is apt to be concentrated in a small area of swamp for many days at a time, then they suddenly shift to new grounds. Sitatunga feed while immersed up to their shoulders and move slowly through the vegetation. Sometimes forelegs may be immersed while hind legs are elevated. They may rear to reach flowers of tall reeds, sedges, grasses and foliage, and males have been known to break branches with their horns. When feeding on long leaves, a sitatunga wraps its tongue around a clump, pulls it into its mouth, and crops it with its incisors. (Estes, 1991; Kingdon, 1974)

Snare trappers value Sitatunga as a food source, but they are also appreciated for their skins.

Positive Impacts: food ; body parts are source of valuable material

None

The sitatunga and bushbuck are close enough genetically to produce viable hybrids in captivity, and almost indistinguishable from the nyala except for pelage and hooves. (Estes, 1991)

Sitatunga is a common host animal for the parasite Schistosoma, a blood fluke found in mesentery blood vessels. (Delany, 1979)

When being pursued, sitatungas may avoid detection by submerging in swamps until only their nostrils and eyes remain above water. (Estes, 1991)

Perception Channels: tactile ; chemical

Lions and wild dogs prey on sitatungas, and leopards catch some that venture into riverine forest. Sitatungas are vulnerable to snare-trappers due to their use of regular pathways. They may also be driven by beaters into nets or into deep water where spearmen in boats easily dispatch them. (Estes, 1991; Honacki et al., 1982)

US Federal List: no special status

CITES: appendix iii; no special status

IUCN Red List of Threatened Species: least concern

Breeding occurs throughout the year, males are polygynous, and females produce a single young at an average interval of 11.6 months. The mean gestation period is 247 days, and sexual maturity is attained at approximately 1 yr. by females and 1.5 yrs. by males.

A male approaches a female in a low stretch posture while the female may back away slowly. When the male comes within a few inches of the female, she may suddenly bound away, causing considerable commotion in the swamp. The male persistently follows, but always stays behind. It is characteristic of this species that the male lay his head and neck on the female's back and lifts his forelegs off the ground in a mounting attempt. The female responds with neck winding, in which her neck angles down obliquely and her head turns sharply up, thrusting forward, upward and back with mouth wide open. The male then mounts with his head resting on her back, and her head and neck point forward and down.

Females hide their calves on platforms in secluded dry reeds growing in deep water. Calves are unable to move slowly and deliberately through the swamp like adults, and follow their mothers closely for several months only after learning how. A mother feeds near the calf's hiding spot, finishes, and walks up to the calf. It licks the young's snout, then moves away. The calf gets up and follows the mother, and she leads it to a protected place where it can suckle. (Estes, 1991; Nowak, 1991)

Range number of offspring: 1 to 2.

Average number of offspring: 1.

Range gestation period: 7.5 to 8.6 months.

Average gestation period: 8.23 months.

Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual

Average birth mass: 4000 g.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (female)
Sex: female: 401 days.

Parental Investment: altricial ; precocial ; post-independence association with parents

Sitatungas may be active during both day and night, but are most active at dawn and dusk (2). A swamp provides a year-round supply of rich food, and sitatungas therefore require only very small home ranges, often using regular, tunnelled pathways through tall reeds and papyrus (4). However, individuals will also sometimes leave the swamp at night, when they are more hidden from predators, to graze at the edge of nearby forests (4). The diet consists of bullrushes, sedges and the leaves of bushes in the swamps, as well as grass in adjacent riverine forests, although fallen fruit and the bark of some trees and bushes are also eaten (4). Sitatungas are usually seen ranging alone or in small, all-female groups (2), although pairs associate for short periods of time for mating and, occasionally, small, temporary mixed groups are formed (4). Breeding occurs throughout the year, with single offspring being usual, after a gestation period of 240 to 250 days (5). Young are born on a dry, trampled mat in the swamp, where they lie in concealment for as long as a month, with only short suckling visits from their mother (2) (4). Nursing lasts from four to six months, but the ties between mother and young do not last long after that, with sub-adults often seen on their own (4). Sexual maturity is reached at one to two years for females, two to two and a half for males, and the life span is up to 19 years (2).

Sitatungas are found in a number of National Parks and Reserves, including Saiwa Swamp National Park in western Kenya, Moyowosi and Selous Game Reserves in Tanzania, Kafue National Park in Zambia, and Okavango Delta and the Moremi Game Reserve in Botswana (4) (6). A Regional Studbook exists to manage captive populations in North America, but this species nevertheless remains rare in captivity (3). The Baltimore Zoo has been recognised for its 'significant efforts in conservation', for having maintained sitatunga for over 33 years, during which a total of 98 captive-bred calves have been born (7). Although captive individuals provide potential for future reintroductions into the wild, a more pressing need for the survival of this species is the enforced prohibition of hunting and the protection of its aquatic habitat, to which it has become so unusually and uniquely adapted.

This medium sized antelope is highly specialised for a semi-aquatic lifestyle, spending the greater part of its life in papyrus swamps of Africa (3). The most obvious physical adaptation to their marshy environment is their long, splayed hooves, which enable the animal to stand and walk on mud and floating islands of vegetation without sinking (3) (4). This unusual animal has a slim face, slender neck and legs, and hindquarters that are higher than the forequarters, giving the sitatunga its peculiar hunched appearance (4). The shaggy, water-resistant coat varies in colour among populations (2), but is generally greyish-brown in males and rufous-brown in females and juveniles (4). Both sexes have distinctive white markings on the cheeks, thighs, throat, and between the eyes, in addition to a pattern of white spots and about six to eight vertical white stripes on the body (4). Males are considerably larger than females (4), and only males have long, spiralled horns, which reach up to 45 to 90 centimetres in length (2). As they mature, males also develop a scraggy mane and a white stripe running down the centre of their back (2).

The sitatunga lives in thickly vegetated, muddy swamps and marshes (4), normally among boggy papyrus beds (2). The animal is a good swimmer, but prefers to rest on dry mounds or floating islands in the swamp, trampling the grass into a springy mat (4). They will, however, flee into deep water when threatened, and individuals have been observed almost completely submerged underwater, with only their nostrils above the waterline (2).

Central and Western Africa (2).

Classified as Least Concern (LC) on the IUCN Red List (1).

The chief threat to the sitatunga comes from people who hunt it. Snares are set along the sitatunga's well-travelled paths in the swamps, or dogs are used to drive the animal into open water, where it can be speared from boats, or on to land, where it is easily captured (4). In many parts of Africa, sitatungas provide a major source of protein as bushmeat, but the animal is also a victim of trophy hunting (3). There is a degree of safety within protected areas, but outside these areas over-hunting is causing a rapid decline in their numbers (4). People are also destroying the sitatunga's aquatic habitat by draining swamps, reducing its distribution and abundance in many parts of its former range (4). Although still relatively widespread, this antelope is now locally threatened in certain areas (3), and has even become recently extinct in Niger, Guinea, and possible in Ghana and Togo too (1).

The Sitatunga (or marshbuck -Tragelaphus spekii) is found in south, west, east and central Africa. They stand at about 1.5m tall, and their waterproof coats and long, thin hooves make them well adapted to living in swampy habitats. They evade predators by submerging themselves underwater keeping only their nostrils above the surface. Humans are their biggest threat, draining swamps and setting snares outside of protected areas. According to the most recent IUCN listing, Sitatungas are now extinct in Niger and possibly Togo. Visit the MammalMAP virtual museum or blog for more info.