The city zoo welcomed two new members on Thursday morning, when a Nilgai gave birth to twins.
The calves, a male and a female, are the first Nilgai to be born in the zoo after a male and four female Nilgais were brought here from the Delhi zoo in 2014. They were born in the new enclosure inaugurated earlier this year.
Another female Nilgai at the zoo is currently pregnant, and is expected to give birth sometime soon.
The gestation period among Nilgais is around eight to nine months.
The Nilgais, which are the largest Asian antelopes, are seen in plenty in North India, and are even regarded as pests as they destroy crops. However, they are rather rare in the southern part of the country, including the forests of Kerala. They are called Nilgai or ‘blue bull’ as the adult male has bluish grey coat.
The females and calves are fawn in colour.
While giving birth to twins is not uncommon among these animals, usually, only one of the twins survive, says Dr. Jacob Alexander, the Zoo veterinarian. That did not occur in this case, although the male calf is rather weak compared to its healthy sibling.
The birth of twins, while a boost for the Nilgai population of the zoo in the present, may possibly be a drawback in the future, due to the prevalence of a condition called Freemartinism among the Nilgais.
Under this condition, when male and female twins are born, the fertility of the female may be reduced due to the development of the female’s gonads being altered by the testosterone produced by the male counterpart.
