Sitatunga

The sitatunga or marshbuck (Tragelaphus spekii) is a swamp-dwelling antelope found throughout central Africa, centering on the Democratic Republic of the Congo, Cameroon, parts of Southern Sudan, Ghana, Botswana, Zambia, Gabon, Tanzania, Uganda and Kenya.The sitatunga is confined to swampy and marshy habitats. Here they occur in tall and dense vegetation as well as seasonal swamps, marshy clearings in forests, riparian thickets and mangrove swamps. The scientific name of the sitatunga is Tragelaphus spekii. The species was first described by the English explorer John Hanning Speke in 1863. Speke first observed the sitatunga at a lake named 'Little Windermere' (now Lake Lwelo, located in Kagera, Tanzania). In his book Journal of the Discovery of the Source of the Nile, Speke called the animal 'nzoé' (Kiswahili name for the animal) or 'water-boc' (due to its resemblance to the waterbuck). The scientific name has often been misstated as T. spekei, and either Speke or Sclater is referred to as the binomial authority. Speke had stated in a footnote in his book that the species had been named Tragelaphus spekii by English zoologist Philip Sclater. However, according to the International Code of Zoological Nomenclature (Article 50.1.1) and the International Commission on Zoological Nomenclature, that acknowledge the person who first described the species, simply declaring Sclater as the authority in a footnote is insufficient to recognise him as the author. Hence, Speke was recognised as the correct authority and T. spekii (where spekii is the genitive of the Latinised 'Spekius') was considered the correct name for the species. The sitatunga is placed under the genus Tragelaphus and in the family Bovidae. In 2005, Sandi Willows-Munro of the University of KwaZulu-Natal (Durban) carried out a mitochondrial analysis of the nine Tragelaphus species. mtDNA and nDNA data were compared. The results showed that sitatunga plus bongo (T. eurycerus) form a monophyletic clade with the mountain nyala (T. buxtoni) and kéwel (T. scriptus). The greater kudu (T. strepsiceros) split from this clade approximately 8.6 million years ago. Within Tragelaphus, the kéwel, bongo, sitatunga and nyala (T. angasii) are particularly close relatives. The bushbuck, that includes both imbabala (T. sylvaticus) and kéwel, and sitatunga are genetically similar enough to hybridise. Hybrids between bongo and sitatunga have proved to be fertile. The sitatunga is more variable in its general characters than any other member of the tribe Strepsicerotini, that consists of the genera Taurotragus (elands) and Tragelaphus, probably because of their confinement to swampy and marshy habitats. On the basis of physical characteristics such as hair texture, coat colour and the coat stripes, up to ten subspecies of the sitatunga have been described. However, these factors may not be reliable since hair texture could vary with the climate, while pelage colour and markings vary greatly among individuals. Moreover, the coat might darken and the stripes and spots on it might fade with age, especially in males. The species might even be monotypic, however, based on different drainage systems, three distinct subspecies are currently recognised: The sitatunga is a medium-sized antelope. It is sexually dimorphic, with males considerably larger than females. The head-and-body length is typically between 136–177 cm (54–70 in) in males and 104–146 cm (41–57 in) in females. Males reach approximately 81–116 cm (32–46 in) at the shoulder, while females reach 72–90 cm (28–35 in). Males typically weigh 76–119 kg (168–262 lb), while females weigh 24–57 kg (53–126 lb). The tail is 14–37 cm (5.5–14.6 in) long. The saucer-shaped ears are 11–17 cm (4.3–6.7 in) long. Only the males possess horns; these are spiral in shape, have one or two twists and are 45–92 cm (18–36 in) long. The sitatunga is almost indistinguishable from the nyala, except in pelage and spoor. Speke pointed out that, though 'closely allied' to the waterbuck, the sitatunga lacks stripes and is spotted instead. The coat colour varies geographically, but, in general, is a rufous red in juveniles and chestnut in females. There are white facial markings, as well as several stripes and spots all over, though they are only faintly visible. White patches can be seen on the throat, near the head and the chest. A pair of inguinal scent glands are present. The coats of males darken with age, becoming gray to dark brown. Males develop a rough and scraggy mane, usually brown in colour, and a white dorsal stripe. There is a chevron between the eyes of the males.