The Nilgai is also known as Blue bull. Nilgai are members of the antelope family of animals. They are relatively common in northern India, and eastern Pakistan. There are also small population of Nilgai in the terai region of southern Nepal, mainly in the Bardia National Park. Even though it is an antelope, it looks quite similar in appearance to an ox. It lives for nearly twenty -one years.
The Blue Bull antelope stands tall, which can grow upto a height of 1.2 to 1.5 m ( 4 to 5 feet) at the shoulders. It grows to length of somewhere between 1.8 to 2 meters and weights nearly 120 to 240 kg. But sometimes the male blue bull goes to a weight over 272 kg. The tails ofa the Nilgai measure 40 to 45 cm in length. A baby Nilgai weights somewhere between 13.6 to 15.9 kg. The strong body of the Nilgai is balanced on comnparatively thin legs.
On the top of the long and narrow head, it has two small conical horns. The horns are straight and slightly forward titled. The horns of the male Nilgai measures 21.6 to 25.4 cm. There is an erectile mane on the nape and back and a ‘hair pennant” in the middle of the underside of the neck. Female nilgai is yellowish – brown in colour and is shorter in height as compared to her male counterparts. As a male nilgai attains maturity, its coat gradually turns blue-grey in colour. There are white spots on the cheers and white colouring on the edges of the lips, and a throat bib. Along the underside is a thin white stripe, which balloons at the rear. The slender legs support a stocky body, which slopes downwards towards the rear. The head is long and slender.
The nilgai is a gregarious and sociable animal usually found in single-sex or mixed-sex herds. The number of members in a herd can be some where between four and twenty. The male blue bulls form a group of 30 to 100 in winter. When male blue bull reach old age, may be foound leading a solitary life. They can found in cultivated or semi-urban areas.
The nilgai is a diurnal animal, found inhabitinbg open jungles / scrubby grassland and woodlands with peaks in activity in the early morning and late afternoon. They tend to keep away from dense forest to avoid the obvious danger of lurking predators. The sense of sight is well developed among this wary species. When chased, nilgai can run upto 48 kmph/29mph.
At the age of 18 months, the nilgai attains maturity. The gestation period last for nearly 8 months. The mother nilgai usually gives birth to twins. In some cases, the number of young ones may be one ot three.
The nilgai are herbivorous creatures and the diet is quite varied and covers almost anything that falls under the term ‘vegetations’. They consume grasses, leaves, buds and fruits.
Predators of Nilgai:
The main predators of the nilgai are tigers and lions. Leopard may attack calves, but they cannot kill one adult nilgai.