NILGAI
Nilgai
Nilgai (Boselaphus tragocamelus) are an antelope, and one of the most commonly seen wild animals of central and northern India and eastern Pakistan; they are also present in parts of southern Nepal. The species has become extinct in Bangladesh. Mature males appear ox-like and are also known as blue bulls. Their average lifespan in captivity is 21.0 years.
Nilgai, also called the nilgai antelope, are the biggest Asian antelope. They were first described by Pallas in 1766. A blue bull is called a nil gai or nilgai in India, with nil meaning blue and gai meaning a bovine animal (literally 'cow') in Hindi. The species name,Boselaphus tragocamelus is derived from 'bos', Latin for ox, 'elaphos', Greek for deer, 'tragos', Greek for a male goat, and 'kamelos', Greek for camel. [Source: Melody Benton, Animal Diversity Web (ADW) /=\, Wikipedia]
Nilgai live in dry areas in variety of land types — savannas, grasslands, mountains, steppes, woodlands and hillsides. They eat grasses, leaves, buds, and fruit. They avoid dense forest and prefer the plains and low hills with shrubs, but may also be found in cultivated areas. In India, they occur in the foothills of the Himalayan Mountains southward to Mysore. The brush country of South Texas is well suited to their natural preferences. /=\
Nilgai, evolved in peninsular India during the Tertiary period (66 million to 2.6 million years ago). , where they are also currently found. They were imported to the United States as zoo animals before the mid-1920s and released into Texas about 1930. Today they are found on large ranches in Kenedy and Willacy counties of Texas. /=\
Nilgai are not endangered. The International Union for Conservation of Nature (IUCN) Red List classifies them as a species of “Least Concern”. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. Nilgai are is hunted for their meat. They may damage food crops in the areas in where they live.
Nilgai Characteristics
Nilgai stand 1.1 to 1.5 meters (3.7 to 5.5 feet) at the shoulder and measure 1.7 to 2.1 meters (5.6 to 6.9 feet) in head-body length, with a 45- to 50-centimeter (1.5 to 1.6 foot) tail. Sexual Dimorphism (differences between males and females) is present: Males are larger than females. Sexes are colored or patterned differently. Ornamentation is different. Males weigh 109 to 288 kilograms (240 to 635 pounds), with a maximum of 308 kilograms (680 pounds) recorded, compared with adult females that weigh 100 to 213 kilograms (220 to 470 pounds). Only males have horns.
Nilgai have a short coat which is yellow-brown in females and turns blue-grey in adult males. Calves are pale brown. The hair of adults is thin and oily, but the skin is thick on the chest and neck of the males. Adult males 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. In males below the "bib" hangs a tuft of hair, or "beard" that can be as long as 13 centimeters. The tips of the long, tufted tail and of the ears are black. They also possess a tubular-shaped "pennant" of long, coarse hair on the midsection of the throat.
Nilgai have thin legs which support their stocky bodies, which slope down from the shoulder. The head is long and slender and males have horns about 20-25 centimeters, which are black in color, sharp, and curved. The males have two black, conical horns, arising close together just behind the eyes. The horns project upwards, but are slightly curved forward; they measure between 15 and 24 centimeters in a fully grown adult. Although the horns are usually smooth, in some older males, they may develop ring-shaped ridges near the base. In contrast, females and young are tawny brown in color, although otherwise with similar markings to the male; they have no horns and only a very small "pennant". Both sexes have an erect mane on the back of the neck, terminating in a bristly "hog-tuft" just above the shoulders.
Nilgai antelopes graze and browse, with grass being their main food source. In Asia, they eat mainly woody plants. In Texas, they eat mesquite, oak, partridge peas, croton, nightshade, and a variety of grasses. Sometime they upgrade their diet by eating plant parts, such as flowers, seeds, fruits, leaves, and stem tops. /=\
Nilgai Behavior
Natural range of the Nilgai
Nigai are diurnal (active during the daytime), motile (move around as opposed to being stationary), and social (associates with others of its species; forms social groups). They sense using touch and chemicals usually detected with smell and are are most active in the early morning and late afternoon. They have good eyesight and hearing that is equal to or better than the white-tail deer, but they do not have a good sense of smell. Though they are normally silent, they can make a roaring like vocalization when alarmed. When chased they can reach speeds up to 29 mph. [Source: Melody Benton, Animal Diversity Web (ADW) /=]
Nilgai tend to form single-sex herds outside of the breeding season. Herds are not of fixed composition, with individuals joining and rejoining through the year. Female herds typically contain three to six adults, together with their calves, whereas bulls form herds of two to 18 individuals. Nilgai antelopes are usually found in herds of about 10 animals, but larger groups of 20 to 70 have been seen. In winter, male blue bulls form herds of 30 to 100 animals in northern India.
Nilgai herds in Texas have been reported to have an average home range of 4.3 square kilometers (1.7 square miles). Both males and females mark their territories by defecating in fixed locations on open ground, with piles building up to reach at least 3 meters (9.8 feet) in diameter. They also possess scent glands on the legs and close to the feet, which they may use to scent mark their daily resting places. They are generally quiet animals, but have been reported to make short guttural grunts when alarmed, and females to make clicking noises when nursing young.
Nilgai Mating, Reproduction and Offspring
Breeding for nilgai occurs in late autumn to early winter. Prior to the rut, males compete to establish dominance. Males display to each other by holding their heads erect and presenting the white patch and tassel on their throats. When they fight they often kneel on their front legs and lunge at each other with their antlers. Gestation lasts 243 to 247 days, resulting in the birth of twins in about 50 percent of cases.
Females and males remain segregated for most of the year, except for when the bulls join the cows for breeding. Breeding groups consist of one dominant bull and one to many cows. Mating usually occurs from December to March, but breeding can occur through the year. Females can conceive at 18 months of age, but very few mate before three years of age. Males are sexually mature by two and half years of age, but cannot compete very well with other males until four years of age. /=\
Nilgai are altricial. This means that young are born relatively underdeveloped and are unable to feed or care for themselves or move independently for a period of time after birth. The post-independence period is characterized by the association of offspring with their parents. /=\
Indian Gazelles
Indian gazelles (Gazella bennettii) are primarily found in the northwestern Indian state of Rajasthan but their range extends from south of the Krishia River, as far east as central India, and as far east as north-central Iran (east of the Zagros Range and south of the Alborz). Sixty to 70 percent of the global population of Indian gazelles live in western Rajasthan. [Source: Dylan McCart, Animal Diversity Web (ADW) /=]
Indian gazelles do well in a variety of habitats. They have been seen in dry deciduous forests, open woodlands, and arid regions such as sand dunes, semi-arid deserts, and arid valleys that have an annual rainfall of 15 to 75 centimeters. Indian gazelles are facultative drinkers; they can withstand relatively long periods without water by conserving metabolic water and taking advantage of water found in vegetation. Their lifespan of Indian gazelles in captivity is up to 12.3 years. They have chromosomal complements of 2n = 49 to 52. There are several subspecies of Indian gazelle: g. b. bennettii, g. b. chiristii, g.b. fusciforms, g.b. karamii, g.b. salinarum, g.b. shikarii.
Indian gazelles are not endangered. On the International Union for Conservation of Nature (IUCN) Red List they are listed as Lower Risk — Least Concern. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. Indian gazelles are considered sacred by the Vishnoi community of Rajasthan, which may explain why there are so many of them there. Indian gazelles are hunted for their leather-making skin, meat, and occasionally for horns, which serve as trophies. They gazelles occasionally feed on crops and are regarded as crop pests. The primary natural predators are golden jackals, Bengal tigers, Indian wolves, Indian leopards, Asiatic cheetahs, crested hawk-eagles, and village and feral dogs.
Indian gazelles were considered threatened in the 1950s due to habitat loss and hunting and poaching. Agricultural practices along with the general increase in human population led to their extirpation in certain areas. In 1994 the species was considered vulnerable but has since recovered. Indian law fully protects Indian gazelles. There are over 25 protected areas within Rajasthan. However, the highest densities of Indian gazelles are found outside of these protected areas and parks, mainly within the Vishnoi communities. There are six major Indian gazelle conservation areas within the small district of Jodhpur, each with large populations. Research and conservation regarding Indian gazelles is carried out by the Ecology and Rural Development Society.
Indian Gazelle Characteristics and Diet
Indian gazelles range in weight from 20 to 25 kilograms (44 to 55 pounds) and range in length from 0.9 to 1.2 meters (2.95 to 3.94 feet). They stand 0.6 to 0.8 meters (two to 2½ feet) at the shoulder. Sexual Dimorphism (differences between males and females) is present: Ornamentation is different. Female horns are usually half the length of and thinner in width than male horns and have less prominent rings. Females tend to weigh less than males and can be as much as 10 centimeters shorter in height. [Source: Dylan McCart, Animal Diversity Web (ADW) /=]
Indian gazelles have sandy, yellowish and red colored fur with a pale white ventral region. According to Animal Diversity Web: Facial markings are well developed: they have a dark brown or black forehead and a light face with dark stripes and a noticeable nose spot. Fur color varies seasonally. In the winter, Indian gazelles are a dark grayish sandy color, and there is a distinct brown band edging the white ventral area of the torso. In the summer, the fur is a darker brown. /=\
Indian gazelles have straight horns with prominent rings and tips that are slightly out-turned. Horns are found on both males and females, although they are relatively shorter in females. Sub-adult males are hard to distinguish from females because of their intermediate horn length. Horns can reach lengths of 25 to 35 centimeters in adult males. Average male horn length of the subspecies Gazella bennetti fuscifrons and grams. b. shakari is 25.7 centimeters; Females of these subspecies have an average horn length of 18.5 centimeters. The braincase is reasonably short and flat, with a long slender premaxilla that has a slight curve. The skull has large auditory bullae and teeth. The toothrows are bowed outward and incurved anteriorly.
Indian gazelles are primarily herbivores (primarily eat plants or plants parts) but are also recognized as folivores (eat leaves) and frugivores (eat fruit). They have nocturnal feeding habits and are most active just prior to sunset and throughout the night. They are better adapted to browsing than grazing, but they can consume legumes and grasses in large quantities. Their diet typically consists of grasses, various leaves, crops and fruits such as pumpkins and melons. A majority of their metabolic water intake comes from the vegetation they consume. The brush and trees that make up their diet are found in mountain ranges and deciduous forests, while grasses and other herbaceous plants are found in valleys and agricultural fields. In the arid Thar Desert, Indian gazelles mainly consume four species of herbs: Crotalaria burhia (42 percent of diet), Ziziphus nummularia (15 percent), Maytenus emerginata (11 percent), and Prosopis cineraria (9 percent). /=\
Indian Gazelle Behavior
Indian gazelles are cursorial (with limbs adapted to running), nocturnal (active at night), crepuscular (active at dawn and dusk), motile (move around as opposed to being stationary), sedentary (remain in the same area), solitary, territorial (defend an area within the home range) and social (associates with others of its species; forms social groups). Little is known about their home range but they are thought to mark their territory with fecal piles. [Source:Dylan McCart, Animal Diversity Web (ADW) /=]
Dylan McCart wrote in Animal Diversity Web: Indian gazelles are swift and agile. They are generally frightened by humans and recede into the mountains or desert to maintain a distance from agriculture and other human activities. Indian gazelles inhabit broken country and rocky mountain settings in Pakistan, seemingly to avoid motorized vehicles. When alarmed, Indian gazelles stamp their forefoot on the ground and emit a sneeze-like hiss through the nose, hence the local name Chinkara (the sneezer). /=\
Indian gazelles are generally observed alone or in groups of three that include a mother and her offspring. Large herds of eight to 10 individuals are occasionally observed. Larger groups are more commonly observed during the breeding seasons. The largest herd recorded was composed of 25 individuals in July 1987 and was observed feeding on millet in a crop field during a drought when the monsoon season did not occur.
Indian gazelles sense using vision, touch and chemicals usually detected with smell and communicate with sound. They also leave scent marks produced by special glands and placed so others can smell and taste them. When alarmed, Indian gazelles stamp their forefoot on the ground and emit a sneeze-like hiss through the nose. /=\
Indian Gazelle Mating, Reproduction and Offspring
Indian gazelles are polygynandrous (promiscuous), with both males and females having multiple partners. They engage in seasonal breeding. Females may give birth yearly. Breeding seasons occur from late August to early October and again from March to the end of April The number of offspring ranges from one to three. [Source: Dylan McCart, Animal Diversity Web (ADW) /=]
Males are extremely territorial and defend their resources with their horns. Male-male competition is frequently observed during the mating season, and males aggressively defend females from other males before mating. Mating begins as a male gazelle touches the underparts of a female gazelle with a stiff leg, called “laufschlag.” When complete, copulation ensues. /=\
The gestation period of Indian gazelles ranges from five to 5.5 months. Young are precocial. This means they are relatively well-developed when born. Parental care is provided by females. The average weaning age is two months. On average females reach sexual or reproductive maturity at one year; males do so at two years.
Females generally give birth to one offspring, but twins have been frequently reported. A majority of births occur in April. Though they are weaned at about two months young may stay with their mother for up to 12 months when she has another offspring.
Four-Horned Antelope
The small four-horned antelope, or chousingha, is another very rare hoofed animal. Native to India and Nepal, it is 80 centimeters to one meter long, not including its 12 centimeters tail, and weighs 17 to 21 kilograms. Found mostly in dense forests and marshland, it feeds on grasses, sedges and other plants, usually near water or forested hills. The male has two pairs of horns, a unique feature among bovids. The front pair is only three to four centimeters long. The rear pair are about twice as long. Little is known about the shy, skittish four-horned antelopes. It communicate with low whistles for identification and barks for alarm. Its brownish coat has a dark stripe on the front of each leg, The muzzle and outer ear surfaces are black. Its offspring are smaller than cats.
Four-horned antelopes (Tetracerus quadricornis) are very wary of humans and rarely viewed in the wild and thus not much is known about them. Population estimates range from 1,000 to 10,000 animals. They have a pecular jerky manner in the way they walk and run. They are sometimes confused with hog deer, but their movements characterize them. In captivity they can live up to 10 years of age. [Source: Brooks Lundeen, Animal Diversity Web (ADW) /=]
Four-horned antelopes are found primarily in wooded areas and and mountains in India. They live in temperate areas, where the climate is similar to that of the U.S. and Europe. They are still widely distributed throughout their range, using hilly country and tall grassy areas for shelter. They prefer open forests but quickly dash into thick cover at the first sign of danger.
Four-horned antelopes is currently listed by the International Union for Conservation of Nature (IUCN) as vulnerable and is on CITES (Convention on International Trade in Endangered Species of Wild) in Appendix III in Nepal. The habitat of this species is being fragmented by human activities. They are eaten by people in India and Nepal, but their meat reportedly does not taste as good as other antelopes. This species is sought after by trophy hunters because of its unique horns. In India ecotours are offered and one the top attractions is often the four-horned antelope. It is also a species sought after by zoos. Among the natural predators of four-horned antelopes are tigers, leopards, wolves, dholes, and small cats. The antelope likely rely primarily on vigilance and speed to escape predators. /=\
Four-Horned Antelope Characteristics and Diet
Four-horned antelopes range in weight from 15 to 25 kilograms (33 to 55 pounds) and have a head and body length of 80 to 110 centimeters (31.5 to 43.3 inches). The shoulder height of 55-65 centimeters, and a tail length of 10-15 centimeters. The hair is short, coarse, and thin, with sexually dimorphic brownish color above and lighter on sides. The insides of the legs are white along with the middle of the belly. Males are dull-red brown above, with white below, and have a dark stripe that runs down the front of each leg. [Source: Brooks Lundeen, Animal Diversity Web (ADW) /=]
Older males are yellowish. Females typically are a brownish-bay color. The horns, only on males, are smooth, short, and conical. The posterior set range from 80 to10 centimeters in length. The front two are typically 25-38 millimeters long, and sometimes only a raised black area of skin is present. The muzzle and outer surface of the ears are blackish brown. The small hooves are split and rounded in the front. Four-horned Antelopes are unique, being the only bovids with four horns.
Four-horned antelopes are primarily herbivores (eat plants or plants parts) but are also recognized as folivores (eat leaves) and frugivores (eat fruit). They are primarily grazers. Among the plant foods they eat are leaves, fruit, grasses and shoots. They are rarely found far from water.
Four-Horned Antelope Behavior and Reproduction
range of the four-horned antelopes
Four-horned antelopes are motile(move around as opposed to being stationary), sedentary (remain in the same area) and solitary. They sense using touch and chemicals usually detected with smell. [Source: Brooks Lundeen, Animal Diversity Web (ADW) /=]
Four-horned antelopes inhabit the same region throughout their lives. Rarely are more than two individuals found together. It is not known whether or not territories are formed or defended. In the rut, males have been found to be extremely aggressive to other males. They can be easily tamed when young, but have been found to be extremely delicate in captivity. Population densities are thought to be less than 0.5 animals per square kilometer.
Four-horned antelopes engage in seasonal breeding. Mating takes place during the rainy season from July to September. The gestation period is 7.5 to eight months. Usually one or two young per litter are born with an average weight of about one kilograms each. Young are precocial. This means they are relatively well-developed when born. Parental care is provided by females. On average females reach sexual or reproductive maturity at one year of age.
Nilgiri Tahrs
Nilgiri tahrs (Nilgiritragus hylocrius) are an ungulate that lives in the Nilgiri Hills and the southern portion of the Western and Eastern Ghats in the states of Tamil Nadu and Kerala in southern India. It is the only species in the genus Nilgiritragus and is closely related to the sheep of the genus Ovis. They have a relatively short life expectancy. Their lifespan in the wild is typically only three to three and a half years.[Source: Adam Herman, Animal Diversity Web (ADW) /=]
Nilgiri tahrs were once abundant in grass-woodland mosaic habitat of Kerala and Tamil Nadu. They are now limited to some 17 populations in the Nilgiri, Anamalai, Palani and Highwavy Hills, the Eravikulam area of the High Range, and possibly a few other mountains in the Western Ghats. They prefer rugged hills, mountain slopes and plateaus at elevations of 1200 to 2200 meters (3937 to 7218 feet). Nilgiri tahr frequent the fringes of the grass-covered plateaus dominated by two main types of grass, Eulalia phaeotrix and Andropogon polyptichus.
On the International Union for Conservation of Nature (IUCN) Red List Nilgiri tahrs are listed as Endangered. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. Nilgiri tahrs are hunted and poached by local people. Their primary threats are loss of habitat and competition for grazing land with domestic livestock. The main natural predators are tigers, Indian wolves and dholes.
Nilgiri tahrs have been protected by government law in India since 1972. These animals are likely candidates for reintroduction and also breed well in captivity. In 1986 total numbers were estimated at 2,000 2,200, relatively unchanged since 1978. Available evidence suggests that the three largest populations have remained approximately stable in recent years. The largest known populations consist of nearly 550 animals each existing in the Eravikulam and Nilgiri Hills National Parks.
See Separate Articles: ARABIAN TAHR: CHARACTERISTICS, BEHAVIOR AND REPRODUCTION factsanddetails.com HIMALAYAN TAHR: CHARACTERISTICS, BEHAVIOR AND REPRODUCTION factsanddetails.com
Nilgiri Tahr Characteristics and Diet
Nilgiri tahrs are goat-like animals with a short coat and short, laterally flattened and curved horns. They range in weight from 50 to 100 kilograms (110 to 220 pounds) and have a head and body length of 90 to 140 centimeters (35.4 to 55.1 inches). They stand 61 to 106 centimeters (24 to 42 inches) at the shoulder and have a tail that is 9-12 centimeters (3.5-4.7 inches) long. [Source: Adam Herman, Animal Diversity Web (ADW) /=]
Sexual Dimorphism (differences between males and females) is present: Males are larger than females. Sexes are colored or patterned differently. Ornamentation is different. Males are black with a silver saddle and bristly mane, while females are grayish brown with white bellies also having latterly-flattened curved horns./=\
Nilgiri tahrs are herbivores (primarily eat plants or plants parts), and are also classified as folivores (eat mainly leaves). They are primarily grazers, Among the plant foods they eat are leaves, various grasses and forbs. Species included among these various forage types are Eulalia phaeothrix, Andropogon polyptichus, Chrysopogon zelan, Eupatorium adenophoru, Strobilanthes kunthianus and Cymbopogon spp. /=\
Nilgiri Tahr Behavior, Communication and Reproduction
Nilgiri tahrs are terricolous (live on the ground),diurnal (active during the daytime), crepuscular (active at dawn and dusk), motile (move around as opposed to being stationary), nomadic (move from place to place, generally within a well-defined range), territorial (defend an area within the home range), social (associates with others of its species; forms social groups), and have dominance hierarchies (ranking systems or pecking orders among members of a long-term social group, where dominance status affects access to resources or mates). [Source: Adam Herman, Animal Diversity Web (ADW) /=]
Nilgiri tahrs are active off and on from dawn to dusk. They living in herd ranging from six to 104 animals, with average group sizes of nine for all-female groups and 27 for mixed herds. Males battle on mountain slopes in competition for mates. Nilgiri tahrs sense using vision, touch, sound and chemicals usually detected with smell and communicate with vision, sound and chemicals usually detected by smelling. They also employ pheromones (chemicals released into air or water that are detected by and responded to by other animals of the same species) and scent marks produced by special glands and placed so others can smell and taste them. Pheromones released in their urine communicate information about mate identification and reproductive activity, spacing mechanisms, and alarm. /=\
range of the Nilgiri tahr
Nilgiri tahrs are polygynous (males have more than one female as a mate at one time). Males compete for access to females through battles and mate with as many females as they can. Females can give birth twice a year but reproductive output varies greatly from year to year. Mating occurs throughout the year but tends to peak in the winter. The number of offspring can be one ot two, with the average being 1.3. The gestation period ranges from six to eight months, with average being seven months. Nilgiri tahrs breed well in captivity.
Nilgiri tahrs are altricial. This means that young are born relatively underdeveloped and are unable to feed or care for themselves or move independently for a period of time after birth. /=\ Parental care is provided by females. Females nurse and care for their offspring until they reach independence. The post-independence period is characterized by the association of offspring with their parents. On average females reach sexual or reproductive maturity at 669 days.
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Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.
Last updated January 2025