Boselaphus tragocamelus

Boselaphus tragocamelus (*)

Cladus: Eukaryota
Supergroup: Opisthokonta
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Classis: Mammalia
Subclassis: Theria
Infraclassis: Placentalia
Superordo: Cetartiodactyla
Ordo: Artiodactyla
Subordo: Ruminantia
Familia: Bovidae
Subfamilia: Bovinae
Genus: Boselaphus
Species: Boselaphus tragocamelus


Boselaphus tragocamelus (Pallas, 1766)

Vernacular names
English: Nilgai
한국어: 닐가이영양
日本語: ニルガイ


* Boselaphus tragocamelus on Mammal Species of the World.
* Mammal Species of the World: A Taxonomic and Geographic Reference, 2 Volume Set edited by Don E. Wilson, DeeAnn M. Reeder


The nilgai (Boselaphus tragocamelus), sometimes called nilgau, is an antelope, and is one of the most commonly seen wild animals of central and northern India and eastern Pakistan; it is also present in parts of southern Nepal. The mature males appear ox-like and are also known as blue bulls. The nilgai is the biggest Asian antelope.


Nilgai stand 1.2-1.5 meters (4–5 feet) at the shoulder and are 1.8-2 meters (6-6.6 feet) long. Their tails are 40-45 centimeters. Mature nilgai typically weigh 120-240 kilograms.

Calves usually weigh 13.6-15.9 kilograms (30-35 pounds) at birth after an 8 month gestation period. Over 60% of births result in twins, though births of 1 or 3 do occur. They reach sexual maturity at around 18 months and can live as long as 21 years.

Nilgai have thin legs and a robust body that slopes down from the shoulder. Their long, narrow heads are topped by two small conical horns which are straight and tilted slightly forward. Horns on trophy males are normally 21.6-25.4 centimeters (8.5-10 inches). They have an erectile mane on the back of the neck and a tubular shaped "hair pennant" on the midsection of the throat.

Female nilgai have a short yellow-brown coat. Males' coats gradually darken to a grey-blue as they reach maturity. They have white spots on the cheeks and white coloring on the edges of the lips. They also have a white throat bib and a narrow white stripe along the underside of the body that widens at the rear.

Nilgai can be found in single sex or mixed sex herds of 4-20, although old bulls are sometimes solitary.


Nilgai antelopes are found in the north Indian plains from the base of the Himalayas in the north, down to the state of Karnataka in the South, and from the Gir forest and from all along the entire eastern length of Pakistan and over across the border of Rajasthan in the West to the states of Assam and West Bengal in the East; in Nepal, they occur patchily in the southern lowlands. The population density in central India is 0.07 animals per square kilometer.
Nilgai pursued by dholes, as drawn by Robert Armitage Sterndale in Denizens of the Jungles, 1886

Historic notes mention the nilgai in southern parts of India but there have also been suggestion that they may be a feral population.

I believe that the Coimbatore and Salem collectorates are almost the only places in Southern India, in which nil-gai are to be found. It is difficult to account for the animals being thus so widely divided from their usual haunts unless as has been generally supposed, these Southern specimens are the progeny of a semi-domesticated herd, which, at some by-gone period, had escaped from the preserve of a native potentate.
—A. C. McMaster (1871)[2]

Refer to Anderson on shikar in southern India. Nilgai have existed north of Bangalore and probably still do.

Nilgai were introduced in Texas in the 1920s by the King Ranch for recreational purposes. Over the years some escaped and they are now free ranging in various southern portions of the state.


Nilgai are diurnal and live in grasslands and woodlands where they eat grasses, leaves, buds, and fruit.

In the wild, females and young males gather in herds of about fifteen individuals while older males are often solitary. Individual male or female nilgai may be encountered in cultivated or semi-urban areas.

Nilgai in India

A blue bull is called a nil gai or nilgai in India, literally from nil meaning blue and gai meaning a bovine animal (literally 'cow'). In fact nilgai were known as the Nilghor (nil = blue , ghor = horse) during the rule of Aurangzeb (Mughal Era) (Gautam Masters dissertation unpubl : Dept. of Wildlife Sciences, Aligarh Muslim Univ). Nevertheless the local belief, that nilgai are a cow and hence sacred, has protected it against hunting.

However, nilgai are a crop menace, causing large-scale damages especially along the gangetic belt, especially in the Rohilkhand division of U.P.. It has been declared as vermin in northern India, and they may be legally hunted after obtaining a permit.


Blue bulls mostly live in herds and in winter, male blue bulls form herds of 30 to 100 animals in northern India. They avoid dense forest and prefer the plains and low hills with shrubs. Blue bulls are usually found in their favoured areas of scrub jungle (acacia forests) grazing upon succulent kader grass. They are not averse to crossing marshlands.
Portrait of a female nilgai

Nilgai can be seen with black bucks (Antilope cervicapra) in the open plains, and in the lower Terai regions they may be seen together with Chital (Axis axis) and 'para' or Hog deer (Axis porcinus). The chital and hog deer, being comparatively smaller in size, usually keep a respectful distance from the much larger nilgai. Sambar (Cervus unicolor) frequent hills and dense forests and are rarely found in the same habitat as nilgai.

The main predators of the blue bulls are tigers (Panthera tigris) and lions (Panthera leo). Leopards are not capable of killing a full grown nilgai but can take calves.

A blue bull can survive for days without water, but they live close to waterholes. The deserts earlier limited their range, but the extension of irrigation canals and proliferation of tube-wells in the Thar desert have helped them colonise the desert districts of Jodhpur, Barmer, Jaisalmer, Bikaner and Ganganagar.

Blue bulls generally come to the same place to deposit their droppings.


The estimated population of nilgai in India is approximately 100,000. Wild populations also exist in Alabama and Texas where they have escaped from private exotic ranches. The Texas population is estimated to be around 15,000.

Like many Indian animals, nilgai are often victim to vehicular accidents, and their carcasses are often seen on major highways in northern India. The main threat to this species is the loss of habitat due to human population growth.

The species is declared by the IUCN as being at low risk of extinction.

Some Texas "exotic ranches" offer nilgai hunting. In January 2010, a nilgai was killed in south Texas by a hunting party that included former White House adviser Karl Rove.[3]


1. ^ Mallon, D.P. (2008). Boselaphus tragocamelus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 29 March 2009. Database entry includes a brief justification of why this species is of least concern.
2. ^ McMaster, A. C. (1871) Notes on Jerdon's Mammals of India. Higginbothams, Madras. (pp. 123-124)
3. ^ Rove, Karl (2010), "Tweet by Karl Rove January 12, 2010", Twitter,, retrieved 2010-01-12

Distinctive white marks are clearly seen on the feet of this male nilgai

* Menon, Vivek. A Field Guide to Indian Mammals. Dorling Kindersley, Delhi, 2003.
* Sheffield, William J., et al. The Nilgai Antelope in Texas (College Station: Texas Agricultural Experiment Station, Texas A&M University System, 1983).

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