Nile Lechwe
Encyclopedia
The Nile Lechwe, Wasserbock or Mrs Gray's Lechwe or waterbuck (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.
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
. 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. 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.
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. 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 human
s, lion
s, crocodile
s, cape hunting dogs and leopard
s. They flee to water if disturbed, but females defend their offspring
from smaller predators by direct attack, mainly kicking.
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 offspring
s, 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.
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 marsh
y areas where they eat aquatic plants.
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. 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
.
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.
(where the water is 10-40 centimeters deep), wetlands, coastal areas, grasslands, steppes, high reed
and cane thickets.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.
(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
. 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.
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
species of antelope
Antelope
Antelope is a term referring to many even-toed ungulate species indigenous to various regions in Africa and Eurasia. Antelopes comprise a miscellaneous group within the family Bovidae, encompassing those old-world species that are neither cattle, sheep, buffalo, bison, nor goats...
found in floodplains in Southern Sudan and far south-western Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
. The wild population were estimated at 30,000 to 40,000 animals in 1983, but no full surveys have been completed since.
Description
Nile Lechwe stand 90 to 100 centimetres at the shoulder and weigh from 70 to 110 kilograms. The coatsCoat (animal)
Coat, or the nature and quality of a show mammal's pelage, is important to the animal fancy in the judging of the animal, particularly at conformation dog shows, cat shows and horse shows...
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
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. 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
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
. Males are chocolate brown to russet with a white 'hood' over the shoulders and small white patches over the eyes. They have long ridge structured horns
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
which are vaguely 's' shaped in profile. The horns
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
, 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.
Ecology
Nile Lechwes can visually signal and vocalize to communicateAnimal communication
Animal communication is any behavior on the part of one animal that has an effect on the current or future behaviour of another animal. The study of animal communication, is sometimes called Zoosemiotics has played an important part in the...
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. When fighting, males duck their heads and use their horns
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
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 human
Human
Humans are the only living species in the Homo genus...
s, lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
s, crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
s, cape hunting dogs and leopard
Leopard
The leopard , Panthera pardus, is a member of the Felidae family and the smallest of the four "big cats" in the genus Panthera, the other three being the tiger, lion, and jaguar. The leopard was once distributed across eastern and southern Asia and Africa, from Siberia to South Africa, but its...
s. They flee to water if disturbed, but females defend their offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
from smaller predators by direct attack, mainly kicking.
Nile Lechwes are crepuscular
Crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...
, 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 offspring
Offspring
In biology, offspring is the product of reproduction, of a new organism produced by one or more parents.Collective offspring may be known as a brood or progeny in a more general way...
s, bachelor males, and mature males with territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
. Males with territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
sometimes allow a bachelor male into their territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...
who is to guard the region and not to copulate.
Feeding
Nile Lechwes feed on succulent grassesSucculent plant
Succulent plants, also known as succulents or fat plants, are water-retaining plants adapted to arid climates or soil conditions. Succulent plants store water in their leaves, stems, and also in roots...
and water plants, forming herds. Wild rice
Wild rice
Wild rice is four species of grasses forming the genus Zizania, and the grain which can be harvested from them. The grain was historically gathered and eaten in both North America and China...
is thought to be a preferred food at the start of the flood season, while a larger proportion of swamp grasses
Swamp
A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...
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 marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
y areas where they eat aquatic plants.
Reproduction
Both sexes reach sexual maturitySexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
when they are 2 years old. Mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
occurs throughout the year, but is peak between February to May. During mating season, young males bend their horns
Horn (anatomy)
A horn is a pointed projection of the skin on the head of various animals, consisting of a covering of horn surrounding a core of living bone. True horns are found mainly among the ruminant artiodactyls, in the families Antilocapridae and Bovidae...
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. A unique form of marking is seen with the start of mating
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
. 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
Rump (animal)
The rump or croup, in the external morphology of an animal, is the portion of the posterior dorsum that is posterior to the loins and anterior to the tail. Anatomically, the rump corresponds to the sacrum....
.
The gestation
Pregnancy (mammals)
In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus; and ends once it leaves the uterus.-Fertilization and implantation:A...
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
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...
it. It is weaned
Weaning
Weaning is the process of gradually introducing a mammal infant, either human or animal, to what will be its adult diet and withdrawing the supply of its mother's milk.The process takes place only in mammals, as only mammals produce milk...
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.
Habitat and distribution
Nile Lechwes usually live in swamplandsSwampland
In physics, the term swampland is used in contrast to the term "landscape," to indicate physical theories or aspects of such theories which could be true if gravity wasn't an issue, but which are not compatible with string theory...
(where the water is 10-40 centimeters deep), wetlands, coastal areas, grasslands, steppes, high reed
Reed (plant)
Reed is a generic polyphyletic botanical term used to describe numerous tall, grass-like plants of wet places, which are the namesake vegetation of reed beds...
and cane thickets.These are mostly found in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
in the Sudd swamps, with smaller numbers in the Machar marshes
Machars
The Machars is a peninsula in Galloway in the south-west of Scotland. The word is derived from the Gaelic word Machair meaning low lying or level land, known as "links" on the east coast of Scotland...
near the Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
border. In Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
, the Nile Lechwe occurs marginally in the south-west, in the Gambela National Park
Gambela National Park
Gambela National Park is a proposed National Park, but the steps needed to fully protect it by the government of Ethiopia have not been completed as of 2002...
, but its population here is unstable due to human activities.
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) 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: ZerafBahr el Zeraf
The Bahr el Zeraf is an arm of the White Nile in the Sudd region of South Sudan, Africa. It is completely contained within the South Sudanese state of Jonglei...
(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
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
the species occurs in Gambela National Park
Gambela National Park
Gambela National Park is a proposed National Park, but the steps needed to fully protect it by the government of Ethiopia have not been completed as of 2002...
. Special license is required to hunt these animals in Sudan
Sudan
Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
. In Ethiopia
Ethiopia
Ethiopia , officially known as the Federal Democratic Republic of Ethiopia, is a country located in the Horn of Africa. It is the second-most populous nation in Africa, with over 82 million inhabitants, and the tenth-largest by area, occupying 1,100,000 km2...
only six animals per year are allowed to be captured with a special license.