Common eland
The common eland ("Taurotragus oryx"), also known as the southern eland or eland antelope, is a savannah and plains antelope found in East and Southern Africa. It is a species of the family Bovidae and genus "Taurotragus". An adult male is around 1.6 metres (5') tall at the shoulder (females are 20 centimetres (8") shorter) and can weigh up to with an average of , for females). It is the second largest antelope in the world, being slightly smaller on average than the giant eland. It was scientifically described by Peter Simon Pallas in 1766. Mainly an herbivore, its  diet is primarily grasses and leaves. Common elands form herds of up to 500 animals, but are not territorial. The common eland prefers habitats with a wide variety of flowering plants such as savannah, woodlands, and open and montane grasslands; it avoids dense forests. It uses loud barks, visual and postural movements and the flehmen response to communicate and warn others of danger. The common eland is used by humans for leather, meat and milk, and has been domesticated in many areas. Eland milk contains more butterfat than cow milk, and can keep longer without pasteurising. It is native to  Angola, Botswana, the Democratic Republic of the Congo, Eswatini, Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Namibia, Rwanda, South Africa, South Sudan, Tanzania, Uganda, Zambia and Zimbabwe but is no longer present in Burundi. While the common eland's population is decreasing, it is classified as of Least Concern by the International Union for Conservation of Nature (IUCN). Etymology. The scientific name of the common eland is "Taurotragus oryx", composed of three words: "tauros", "tragos" and "oryx". "Tauros" is Greek for a bull or bullock, meaning the same as the Latin "taurus". "Tragos" is Greek for a male goat, referring to the  tuft of hair that grows in the eland's ear and its resemblance to a goat's beard. "Oryx" is Latin and Greek (genitive: "orygos") for pickaxe, referring to the pointed horns of North African antelopes like the common eland and scimitar-horned oryx. The name 'eland' is Dutch for "elk" or "moose". It has a Baltic source similar to the Lithuanian "élnis", which means "deer". It was borrowed earlier as "ellan" (French) in the 1610s or "Elend" (German). When Dutch settlers came to the Cape Province, they named it after the large, herbivorous moose. In Dutch, the animal is  called "eland antelope" to distinguish it from the moose, which is found in the northern boreal forests. Physical description. Common elands are spiral-horned antelopes. They are sexually dimorphic, with females being smaller than the males. Females weigh , measure from the snout to the base of the tail and stand at the shoulder. Bulls weigh , are from the snout to the base of the tail and stand at the shoulder. The tail is long. Male elands can weigh up to . Their coat differs geographically, with elands in northern part of their range having distinctive markings (torso stripes, markings on legs , dark garters and a spinal crest) that are absent in the south. Apart from a rough mane, the coat is smooth. Females have a tan coat, while the coats of males are darker, with a bluish-grey tinge. Bulls may also have a series of vertical white stripes on their sides (mainly in parts of the Karoo in South Africa). As males age, their coat becomes more grey. Males also have dense fur on their foreheads and a large dewlap on their throats. Both sexes have horns with a steady spiral ridge (resembling that of the bushbuck). The horns are  visible as small buds in newborns and grow rapidly during the first seven months. The horns of males are thicker and shorter than those of females (males' horns are long and females' are long), and have a tighter spiral. Males use their horns during rutting season to wrestle and butt heads with rivals, while females use their horns to protect their young from predators. The common eland is the slowest antelope, with a peak speed of per hour that tires them quickly. However, they can maintain a per hour trot indefinitely. Elands are capable of jumping up to from a  standing start when startled (up to for young elands). The common eland's life expectancy is generally between 15 and 20 years; in captivity some live up to 25 years. Eland herds are accompanied by a loud clicking sound that has been subject to considerable speculation. It is believed that the weight of the animal causes the two halves of its hooves to splay apart, and the clicking is the result of the hoof snapping together when the animal raises its leg. The sound carries some distance from a herd, and may be a form of communication. Taxonomy. The common  eland was first described in 1766 by the German zoologist and botanist Peter Simon Pallas. It belongs to the order Artiodactyla, family Bovidae and subfamily Bovinae. Common elands are sometimes considered part of the genus "Tragelaphus" on the basis of molecular phylogenetics, but are usually categorized as "Taurotragus", along with the giant eland ("T. derbianus"). Subspecies. Three subspecies of common eland have been recognized, though their validity has been disputed. Genetics and evolution. Male elands have 31 diploid chromosomes and females have 32. The male (Y) chromosome has been translocated to the short arm of an autosome. Both the X  chromosome and Y chromosome replicate late; they do not match well and are variable. The chromosomes resemble those of the greater kudu ("Tragelaphus strepsiceros"). Male elands and female greater kudus can produce a viable male hybrid, though it is not known if it is sterile. An accidental crossing of an east African common eland ("T. o. pattersonianus"') with an east African kudu ("T. s. bea") occurred in the San Diego Zoo Safari Park. This was believed to be due to the absence of male kudus in the herd. The hybrid produced was sterile, which was unexpected before the study. The  study conformed the chromosome numbers of both the eland and the kudu and the strangeness of their attached Y chromosomes. Reports state that repeated matings of male elands with domestic ("Bos primigenius") and zebu cows ("Bos indicus") have also produced sterile hybrids. Female elands can also act as surrogates for bongos. The Bovidae family ancestors of the common eland evolved approximately 20 million years ago in Africa; fossils are found throughout Africa and France but the best record appears in sub-Saharan Africa. The first members of the tribe "Tragelaphini" appear 6 million years in the past during the late  Miocene. An extinct ancestor of the common eland ("Taurotragus arkelli") appears in the Pleistocene in northern Tanzania and the first "T. oryx" fossil appears in the Holocene in Algeria. In 2010, a genetic study was made basing on the evolutionary history of common elands. Located in the sub-Saharan savanna biome of east and southern Africa, the study used methods like analysis of mitochondrial DNA control-region fragments from 122 individuals to learn more about various topics, such as the phylogeography, genetic diversity, demographic history of the species. The conclusions strongly supported the presence of a longer-standing population in  the south and a mosaic of Pleistocene refugia in the east. It is believed that today their extinction from these parts could be due to colonization. The similarity of dates obtained from more studies indicates a significant event c. 200 ka, which had brought a great change in the genetic history of the species. Habitat and distribution. Common elands live on the open plains of southern Africa and along the foothills of the great southern African plateau. The species extends north into Ethiopia and most arid zones of South Sudan, west into eastern Angola and Namibia, and south to South  Africa. However, there is a low density of elands in Africa due to poaching and human settlement. Elands prefer to live in semi-arid areas that contain many shrub-like bushes, and often inhabit grasslands, woodlands, sub-desert, bush, and mountaintops with altitudes of about . Elands do, however, avoid forests, swamps and deserts. The places inhabited by elands generally contain "Acacia", "Combretum", "Commiphora", "Diospyros", "Grewia", "Rhus" and "Ziziphus" trees and shrubs; some of these also serve as their food. Eland can be found in many National Parks and reserves today, including Nairobi National Park and Tsavo East National Park, Tsavo  West National Park, Masai Mara National Reserve, (Kenya); Serengeti National Park, Ruaha National Park and Tarangire National Park, Ngorongoro Crater, (Tanzania); Kagera National Park (Rwanda); Nyika National Park (Malawi); Lake Mburo National Park (Uganda); Kidepo Valley National Park (Uganda); Luangwa Valley and Kafue National Park (Zambia); Hwange National Park, Matobo National Park, Tuli Safari Area and Chimanimani Eland Sanctuary (Zimbabwe); Kruger National Park, Kgalagadi Transfrontier Park, Giant's Castle and Suikerbosrand NR (South Africa). They live on home ranges that can be 200–400 km for females and juveniles and 50 km for males. Ecology and behavior. Common elands are nomadic  and crepuscular. They eat in the morning and evening, rest in shade when hot and remain in sunlight when cold. They are commonly found in herds of up to 500, with individual members remaining in the herd anywhere from several hours to several months. Juveniles and mothers tend to form larger herds, while males may separate into smaller groups or wander individually. During estrus, mainly in the rainy season, groups tend to form more regularly. In southern Africa common elands will often associate with herds of zebras, roan antelopes and oryxes. Common elands communicate via gestures, vocalizations, scent cues and  display behaviors. The flehmen response also occurs, primarily in males in response to contact with female urine or genitals. Females will urinate to indicate fertility during the appropriate phase of their estrous cycle, as well as to indicate their lack of fertility when harassed by males. If eland bulls find any of their predators nearby, they will bark and attempt to attract the attention of others by trotting back and forth until the entire herd is conscious of the danger. Some of their main predators include lions, African wild dogs, cheetahs and spotted hyenas. Juvenile elands are more vulnerable than  adults to their predators. Diet. Common elands are herbivores that browse during drier winter months but have also adapted to grazing during the rainy season when grasses are more common. They require a high-protein diet of succulent leaves from flowering plants but will consume lower quality plant material if available including forbs, trees, shrubs, grasses, seeds and tubers. The eland can conserve water by increasing its body temperature. Grasses the eland eats include "Setaria" and "Themeda" and fruits from "Securinega" and "Strychnos". Large antelope can survive on lower quality food in times of little rain. Elands feed during the  night in hot weather and sleep for long periods during the day. Most of their water is obtained from their food, though they will drink water when available. As they quickly adjust to the surroundings due to seasonal changes and other causes, they also change their feeding habits. They also use their horns to break off branches that are hard to reach. Sociability and reproduction. Females are sexually mature at 15–36 months and males at 4–5 years. Mating may occur anytime after reaching sexual maturity, but is mostly seen in the rainy season. In Zambia, young are born in July  and August, while elsewhere it is the mating season. Mating begins when elands gather to feed on lush green plains with plentiful grass, and some males and females start mating with each other in separate pairs. Males chase the females to find out if they are in estrus. They also test the female's urine. Usually, a female chooses the most dominant and fit male to mate with. Sometimes she runs away from males trying to mate, causing more attraction. This results in fights between males, in which their hard horns are used. It is 2–4 hours before a female  allows a male to mount. Males usually keep close contact with females in the mating period. The dominant male can mate with more than one female. Females have a gestation period of 9 months, and give birth to only one calf each time. Males, females and juveniles each form separate social groups. The male groups are the smallest; the members stay together and search for food or water sources. The female group is much larger and covers greater areas. They travel the grassy plains in wet periods and prefer bushy areas in dry periods. Females have a complex linear hierarchy . The nursery and juvenile group is naturally formed when females give birth to calves. After about 24 hours of the delivery, the mother and calf join this group. The calves start befriending each other and stay back in the nursery group while the mother returns to the female group. The calves leave the nursery group when they are at least two years old and join a male or female group. Diseases and parasites. Common elands are resistant to trypanosomiasis, a protozoan infection that has the tsetse fly as a vector, but not to the "Rhipicephalus"-transmitted disease theileriosis. The disease-causing  bacteria "Theileria taurotragi" has caused many eland deaths. "Clostridium chauvoei", another bacterium, can be harmful as well. Eland are also hosts to several kinds of ticks. In one study an eland was found to be host to the "Amblyomma" species "A. gemma" and "A. variegatum", and "Rhipicephalus" species "R. decoloratus", "R. appendiculatus", "R. evertsi", "R. pulchellus" and "R. pravus". Elands produce antibodies for Brucella bacteria, but none for "Mycobacterium paratuberculosis" or various types of pneumonia like contagious bovine pneumonia and contagious caprine pneumonia, normally infectious in cows or antelopes. Interaction with humans. Conservation. Currently, common elands are not endangered. They  are conserved by the United States Endangered Species Act, and regulated in international trade by the Convention on International Trade in Endangered Species. Using ground counts and aerial surveys, the International Union for Conservation of Nature (IUCN) calculates the population density of the common eland to be between 0.05 and 1 per square kilometre with a total population estimate of 136,000. Populations are considered stable or increasing in the countries of Namibia, Botswana, Zimbabwe, South Africa, Malawi and possibly Tanzania. The population is, however, gradually decreasing due to habitat loss, caused by expanding human settlements and poaching for its superior  meat. As they are docile and inactive most of the time, they can easily be killed. The species became extinct in Eswatini and Zimbabwe, but has been reintroduced. The IUCN states that about half of the estimated total population lives in protected areas and 30% on private land. Protected areas that support major populations include Omo (Ethiopia), Serengeti, Katavi, Ruaha and Selous-Kilombero (Tanzania), Kafue and North Luangwa (Zambia), Nyika (Malawi), Etosha (Namibia), Kgalagadi Transfrontier Park (Botswana/South Africa) and Ukhahlamba Drakensberg Park (South Africa). Most of these populations appear to be stable. Relatively large numbers of common eland now  live on private land, particularly in Namibia, Zimbabwe and South Africa, reflecting its value as a trophy animal. Common elands have also been widely domesticated in Zimbabwe, South Africa and Kenya, as well as in Russia and Ukraine. Uses. The common eland is sometimes farmed and hunted for its meat, and in some cases can be better used than cattle because it is more suited to African climates. This has led to some Southern African farmers switching from cattle to eland. Common elands are also pictured as supporters in the coat of arms of Grootfontein, Namibia. Husbandry. Common elands have  a mild temperament and have been successfully domesticated for meat and milk production in South Africa and Russia. Their need for water is quite low because they produce urine with a high-urea content, but they require a substantial grazing area, along with salt licks and large amounts of supplementary foods like maize, sorghum, melons and beans which can be expensive. A female can produce up to of milk per day that is richer in milkfat than cow milk. The pleasant-tasting milk has a butterfat content of 11-17% and can be stored for up to eight months if  properly prepared, versus several days for cow milk. Housing common elands is difficult due to their ability to jump over fences as high as or simply break through using their substantial mass. Sometimes, wild eland will break through enclosures to mix with domesticated ones. Common elands can reproduce in captivity, but calf survival is low and the young may need to be separated from their mothers to ensure health and adequate feeding. Husbandry requires care because the generally placid animals startle easily and require large amounts of space.