Nile Lechwe

Nile Lechwe
Conservation status
Endangered (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Artiodactyla
Family:	Bovidae
Genus:	Kobus
Species:	K. megaceros
Binomial name
Kobus megaceros (Fitzinger, 1855)

The Nile Lechwe, Wasserbock or Mrs Gray's Lechwe or waterbuck^[2] (Kobus megaceros) is an endangered species of antelope found in floodplains in Southern Sudan and far south-western Ethiopia. The wild population were estimated at 30,000 to 40,000 animals in 1983, but no full surveys have been completed since.

Description

Head from the description by Gray as Kobus maria

Nile Lechwe stand 90 to 100 centimetres at the shoulder and weigh from 70 to 110 kilograms. The coats are shaggy with the hair on the cheeks particularly long in both sexes, and males may have even longer hair on their necks. Nile Lechwes exhibit extreme sexual dimorphism.^[3] Females are golden-brown (juveniles also have golden-brown coat, but the color changes to dark brown in young males when they reach 2-3 years of age) with a white underbelly and no horns. Males are chocolate brown to russet with a white 'hood' over the shoulders and small white patches over the eyes.^[4][2] They have long ridge structured horns which are vaguely 's' shaped in profile. The horns, that grow 50-80 centimeter long, are stongly ridged at their bases and are curved at the tips. Nile Lechwes live an average of 10 to 11.5 years, and most uncommonly 19 years. Yearlings are usually infected by warble flies, which can also make them unhealthy.^[5]

Ecology

Nile Lechwes can visually signal and vocalize to communicate with each other. They rear high in the air in front of their opponent and turn their head to the side while displaying. Females are quite loud, making a toad-like croaking when moving.^[3] When fighting, males duck their heads and use their horns to push against each other. If one male is significantly smaller than the other, he may move next to the larger male in a parallel position and push from there, which prevents the larger male from pushing with all his force. Known predators are humans, lions, crocodiles, cape hunting dogs and leopards. They flee to water if disturbed, but females defend their offspring from smaller predators by direct attack, mainly kicking.^[5]

Nile Lechwes are crepuscular, which means that they are active in the early morning and late afternoon. They gather in herds of up to fifty females and one male or in smaller all male herds. They divide themselves into three social groups: females and their new offsprings, bachelor males, and mature males with territory. Males with territory sometimes allow a bachelor male into their territory who is to guard the region and not to copulate.^[5]

Feeding

The main diet of Nile Lechwes mostly includes grass.

Nile Lechwes feed on succulent grasses and water plants, forming herds. Wild rice is thought to be a preferred food at the start of the flood season, while a larger proportion of swamp grasses are consumed when the waters recede. Nile Lechwes have the special capability to wade in shallow waters and swim in deeper waters. It may feed on young leaves from trees and bushes, rearing up to reach this green vegetation. Nile Lechwe are also found in marshy areas where they eat aquatic plants.^[3]

Reproduction

Both sexes reach sexual maturity when they are 2 years old. Mating occurs throughout the year, but is peak between February to May. During mating season, young males bend their horns to the ground as if to poke the earth. Males fight in the water, their heads submerging in horn-to-horn combat, for dominance. These contests are usually short and violent. As in many other animals, the dominant male copulates with the female.^[4] A unique form of marking is seen with the start of mating. The male bends his head to the ground and urinates on his throat and cheek hair. He then rubs his dripping beard on the female's forehead and rump.^[4][5]

The gestation period is 7-9 months long at an average, after which a single calf is born. Infants weigh about 4.5 to 5.5 kg. Females experience estrus again about a month after producing young. After its birth the calf is kept hidden in thick vegetation for 2-3 weeks, where the mother nurses it. It is weaned for the next 5-6 months, and between 6-8 months of its life the calf is ready to be independent and join the herd.^[4][5]

Habitat and distribution

Nile Lechwes usually live in swamplands (where the water is 10-40 centimeters deep), wetlands, coastal areas, grasslands, steppes, high reed and cane thickets.^[3][4]These are mostly found in Sudan in the Sudd swamps, with smaller numbers in the Machar marshes near the Ethiopia border. In Ethiopia, the Nile Lechwe occurs marginally in the south-west, in the Gambela National Park, but its population here is unstable due to human activities.^[1]

Uses and conservation

Nile Lechwes may help reduce grass fires by trampling the grass when grazing, making a natural firewall. They are a highly prized trophy to an African hunter and may be traded for food or other resources. They were also traditionally hunted as a source of food. This endangered species (as of 2008)^[1] is gradually becoming rare due to excessive hunting and habitat loss. Still, conservation efforts are being made. According to the IUCN, in Sudan, the Nile Lechwe occurs in three protected areas: Zeraf (however here the situation for wildlife is likely to worsen as a result of oil exploration and exploitation in the region), Fannyikang and Shambe, and in Ethiopia the species occurs in Gambela National Park.^[1] Special license is required to hunt these animals in Sudan. In Ethiopia only six animals per year are allowed to be captured with a special license.^[5]

References

1. ^ ^{a b c d} IUCN SSC Antelope Specialist Group (2008). Kobus megaceros. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 5 April 2009. Database entry includes a brief justification of why this species is of endangered.
2. ^ ^{a b} Groves, Colin; Peter Grubbs (2011) (in English) (PDF). Ungulate Taxonomy. USA: The Johns Hopkins University Press. p. 191. ISBN 978-1-4214-0093-8. http://books.google.co.in/books?id=v3uZtA1ZpTAC&pg=PA191&dq=kobus+megaceros&hl=en&ei=C-evTsvGLYKqrAf11K1y&sa=X&oi=book_result&ct=result&resnum=1&ved=0CC0Q6AEwAA#v=onepage&q=kobus%20megaceros&f=false. 
3. ^ ^{a b c d} "Nile lechwe". ARKive. http://www.arkive.org/nile-lechwe/kobus-megaceros/. 
4. ^ ^{a b c d e} Huffman, Brent. "Nile lechwe (Kobus megaceros)". UltimateUngulate. http://www.ultimateungulate.com/Artiodactyla/Kobus_megaceros.html. 
5. ^ ^{a b c d e f} Corrie, Julia. "Kobus megaceros". University of Michigan Museum of Zoology. Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Kobus_megaceros.html.