|White tiger cub turns black in Chennai Zoo|
| CHENNAI: One of the three 'white' tigers born in Vandalur zoo in June seems to have changed its colours — most of its body and legs are now black.|
The black cub, along with its completely white siblings, was on display for the public to see for the first time at the Arignar Anna Zoological Park in Vandalur on Sunday, and drew hordes of excited visitors.
A black tiger is something of a rarity and zoo officials are quite excited by the development. "The colouring might be due to genetic reasons. A black cub is exactly the same as a regular tiger in all aspects, except for its skin colour," said zoo director KSSVP Reddy, who is also chief conservator of forests.
Reddy ruled out the possibility of inbreeding as the reason for the unusual colouring. "Inbreeding occurs only over generations. The mother, white tigress Anu, has only given birth twice," he said.
Zoo biologists said the large presence of the pigment melanin in the cub was probably the reason for 80% of its skin being black. The skin colour of tigers is determined by the presence of black and yellow pigments. In most tigers, the colour yellow dominates over black to give them their characteristic colouring.
"In this cub, the reverse has happened — black is the dominant colour," said senior zoo biologist Dr Manimozhi. "We are monitoring the cub. The skin colour that he grows into when he reaches adulthood will be the permanent one," he said. It is the dominance of yellow pigment that enables tigers to survive in the wild for long, he added. "In fact, this is the reason why most white tigers are found only in zoos and not in the wild," Manimozhi said.
The birth of the three cubs on June 6 has taken the tiger population in the zoo to 15. Zookeepers said the cubs, which weigh about eight kg each, are active and healthy. They are given a regular diet of chicken and beef.