The Nile lechwe or Mrs Gray's lechwe (Kobus megaceros) is an endangered species of antelope found in swamps and grasslands in South Sudan and Ethiopia. Females are golden-brown with white underbellies and no horns. Juveniles also have a golden-brown coat, but the color changes to dark brown in young males when they reach two to three years of age. Adult males are blackish-brown to russet with white 'hoods' over their shoulders and small white patches over their eyes. The horns of the adult males are long, strongly ridged at their bases and are curved at the tips.
Nile lechwe are crepuscular, active in the early morning and late afternoon. They gather in herds of up to 50 females and one male or in smaller all-male herds. They divide themselves into three social groups: females and their new offspring, bachelor males, and mature males with territories. A males with territory sometimes allows a bachelor male into his territory to guard the region and not to copulate.
The gestation period is seven to 9 months long on average, after which a single calf is born. Infants weigh about . Females experience estrus again about a month after producing young. After its birth, the calf is kept hidden in thick vegetation for two to three weeks, where the mother nurses it. It is weaned at five to six months, and a few months later is ready to be independent and join the herd. Nile lechwe are endemic to South Sudan and Ethiopia. In South Sudan, the majority of the population occurs in the Sudd swamps, and in the Machars near the Ethiopian border in smaller numbers. In Ethiopia occurs in the southwest, in Gambela National Park, but in very less numbers possibly due to human settlement and habitat degradation. The habitat of the Nile lechwe has been severely affected by civil wars, human displacement and resettlement, firearm attacks and increased hunting. Even its seasonal movements were restricted due to large populations of cattle in and around its range. The Nile lechwe population in the Sudds, however, remained somewhat stable throughout this period.
Conservation
The Nile lechwe has been classified under the Endangered category by the International Union for Conservation of Nature and Natural Resources (IUCN). In 1983, aerial surveys gave a total population estimate of 30,000-40,000 individuals, of which 95 percent were concentrated in the Sudds and the rest occurred between Sudan and Ethiopia. A population of around 150 was also reported from the swamps in Gilo River in 1967. There is also an increasing population held in captivity.