The nilgai ( Boselaphus tragocamelus) (, literally meaning "blue cow") is the largest antelope of Asia, and is ubiquitous across the northern Indian subcontinent. It is the sole member of the genus Boselaphus, which was first scientifically described by Peter Simon Pallas in 1766. The nilgai stands at the shoulder; males weigh , and the lighter females . A sturdy thin-legged antelope, the nilgai is characterised by a sloping back, a deep neck with a white patch on the throat, a short crest of hair along the neck terminating in a tuft, and white facial spots. A column of pendant coarse hair hangs from the dewlap ridge below the white patch. Sexual dimorphism is prominent – while females and juveniles are orange to tawny, adult males have a bluish-grey coat. Only males possess horns, long.
The nilgai is diurnal animal (active mainly during the day). The animals band together in three distinct kinds of groups: one or two females with young calves, three to six adult and yearling females with calves, and all-male groups with two to 18 members. Typically tame, the nilgai may appear timid and cautious if harassed or alarmed; it flees up to , or even , galloping away from the source of danger. Herbivores, nilgai prefer grasses and herbs, though they commonly eat in the dry tropical forests of India. Females become sexually mature by two years, while males do not become sexually active until four or five years old. The time of the year when mating takes place varies geographically, but a peak breeding season lasting three to four months can be observed at most places. Gestation lasts eight to nine months, following which a single calf (sometimes twins or even triplets) is born. As typical of several bovid species, nilgai calves stay hidden for the first few weeks of their lives. The lifespan of the nilgai is around ten years.
The nilgai prefers areas with short bushes and scattered trees in and grassy plains. It is commonly found on agricultural land and rarely in dense forests. Major populations occur in the Indian and Nepal Terai. It was thought to be extinct in Bangladesh. The nilgai was introduced to Texas in 1924. The nilgai is categorised as Least Concern on the IUCN Red List. The nilgai has been associated with Indian culture since the Vedic period (1500–500 BCE). They were hunted in the Mughal era (16th to 19th centuries) and are depicted in numerous miniatures. Nilgai have been considered a pest in several states, as they ravage crop fields and cause considerable damage. In Bihar, authorities have classified the nilgai as vermin.
The generic name Boselaphus comes from the combination of the Latin bos ("cow" or "ox") and the Greek ("deer"). The specific name tragocamelus is derived from the joining of the two Greek words tragos ("he-goat") and kamelos ("camel"). The binomial combination was first used by English zoologist Philip Sclater in 1883.
Though the tribe Boselaphini has no African representation today,
Remains of the nilgai dating back to the Pleistocene have been discovered from the Kurnool caves in southern India. Evidence suggests that they were hunted by humans during the Mesolithic period (5,000 to 8,000 years ago).
The nilgai is the largest antelope in Asia.
The maximum recorded length of the skull is . The dental formula is . The milk teeth are totally lost and the permanent dentition completed by three years of age. The permanent teeth get degraded with age, showing prominent signs of wear at six years of age. The nilgai has sharp ears and eyes,
The Indian population was estimated at one million in 2001. The nilgai were first introduced to Texas in 1924, by Caesar Kleberg, onto a ranch near the Norias Division of the King Ranch, one of the largest ranches in the world. The feral population saw a spurt toward the latter part of the 1940s, and gradually spread out to adjoining ranches.
Historic notes mention nilgai in southern India, but these may have been feral:
Fights take place in both sexes and involve pushing their necks against each other or ramming into one another using horns. Fights can be gory; despite the protective skin deep, lacerated wounds and even deaths might occur. Display behaviour focuses on the throat patch and the beard, and threatening opponents by pointing the horns toward them. A young male was observed making a submissive display in the Sariska Reserve by kneeling before an adult male, who stood erect. The nilgai mark their territories by forming dung piles as much as in radius. The defecation process is elaborate-the antelope stands with his legs about a metre apart, with the rump lowered and the tail held almost vertical; it stays in the same posture for at least ten seconds after relieving itself. The process is not as elaborate in the females as it is in the males.
In India, the nilgai shares its habitat with the four-horned antelope, chinkara, chital and blackbuck; its association with the gaur and the water buffalo is less common. In Ranthambore National Park, the nilgai and the chinkara collectively prefer the area rich in Acacia and Butea species, while the sambar deer and the chital preferred the forests of Anogeissus and Grewia species. In India, the Bengal tiger and Asiatic lion prey on the nilgai but the latter is not a significant predator of this antelope. also prey on the nilgai, though they prefer smaller prey. generally attack juveniles. Other predators includes the Indian wolf and striped hyena.
Gestation lasts eight to nine months, following which a single calf or twins (even triplets at times) are born. In a 2004 study in the Sariska reserve, twins accounted for as high as 80 percent of the total calf population. Births peak from June to October in the Bharatpur National Park, and from April to August in southern Texas. Calves are precocial; they are able to stand within 40 minutes of birth, and forage by the fourth week. Pregnant females isolate themselves before giving birth. As typical of several bovid species, nilgai calves are kept in hiding for the first few weeks of their lives. This period of concealment can last as long as a month in Texas. Calves, mainly males, bicker playfully by neck-fighting. Young males would leave their mothers at ten months to join bachelor groups. The lifespan of the nilgai is typically ten years in Texas.
In India, the nilgai is protected under Schedule III of the Wildlife Protection Act of 1972. Major protected areas for the nilgai across India include: Gir National Park (Gujarat); Bandhavgarh National Park, Bori Wildlife Sanctuary, Kanha National Park, Pachmarhi Biosphere Reserve, Panna Tiger Reserve, Pench Tiger Reserve, Sanjay National Park, Satpura National Park (Madhya Pradesh); Tadoba Andhari Reserve (Maharashtra); Kumbhalgarh Wildlife Sanctuary, Sultanpur National Park in Gurgaon, Ranthambore National Park and Sariska Tiger Reserve (Rajasthan).
The nilgai is extensively featured in paintings, dagger hilts and texts from the Mughal Empire era;
For centuries Indian villagers have associated the nilgai with the cow, a sacred animal revered by , and the name ("gai" means "cow" in Hindi) indicates the similarity they saw with the cow.
The governments of Bihar, Maharashtra and Uttarakhand have urged the Government of India to declare the nilgai as vermin; the proposal has been implemented in Bihar, where nilgai can now be hunted to minimise the damages incurred by locals. The Uttar Pradesh government has given farmers and firearm licence holders the right to cull the animals. However, animal rights activists in various parts of India were unhappy with the decision. Shivanshu K. Srivastava, a columnist and Activism, wrote that "The culling of nilgais (blue bulls) in Bihar in July 2016 was so deplorable that it doesn't need any justification. The excuse given for this slew by the State government, the then environment minister Prakash Javadekar and the judiciary is so illogical that it mocks all the solutions available to stop the nilgais from destroying the farms. We live in the 21st century and culling is only the very last option we have. The farmers can either opt for fencing around the farmlands or if it's unaffordable, then the government can give ordinances to relocate them to the forests." The state governments have attempted other initiatives to curb the nilgai: in November 2015, the Government of Rajasthan came up with a proposal to allow shooting nilgai with non-lethal darts to inhibit fertilisation in their bodies, so as to regulate their increasing populations. As the name "nilgai" appeals to the religious sentiments of Hindus, the Government of Madhya Pradesh has sought to officially rename it rojad (Hindi for "forest antelope") and the Government of Haryana to rename it as roze in a bid to make their culling acceptable.
in 1994, it becamer known that the nilgai's faeces contains nearly 1.6 percent nitrogen, which could enhance the quality of the soil up to a depth of . Seeds in the droppings could easily germinate and assist in afforestation.
In September 2019, a video surfaced of a nilgai being buried alive with an excavator in Bihar as part of the culling. The state forest department has claimed to have begun an investigation to find those responsible.
Evolution
Description
Distribution and habitat
Behavior and ecology
Diet
Reproduction
Threats and conservation
Cultural significance
Culling and conservation
Notes
External links
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