Collars preventing tigers from breeding?
Collared tigers in Ranthambhore National Park (RNP) and Sariska are showing an intriguing behaviour that has flummoxed wildlife scientists. With a contraption weighing over 1.5 kg around their necks, they are finding it difficult to breed.
The scientists suspect that tigress No. 17 in Ranthambhore and five relocated big cats, including three females, at Sariska Tiger Reserve were finding the radio collars too much of a burden when it comes to getting cozy with a mate.
The five tigers at Sariska were relocated in phases from Ranthambhore since 2008 to repopulate the reserve. Sariska became a “tigerless” reserve in 2004.
Now, failed breeding has put a question mark on the repopulation programme of Sariska that was taken up at the behest of Prime Minister Manmohan Singh.
Collars are put on tigers to monitor their movements – usually on those who have been either shifted from one forest area to another or if the animal’s territory falls in a sensitive location close to the reserve’s border and near human habitation.
None of these apply to Ranthambhore’s T17 – renamed Krishna after Rajasthan’s champion athlete Krishna Punia. She is the only tiger born and brought up in Ranthambhore carrying a radio collar since June 23, 2008.
For the record, T17 is the most sighted tiger of Ranthambhore with a territory that ranges from Jhalra, Padma Talab, Rajbagh, Malick Talab, Manduk and Singhdwar of the park.
To make matters worse, her radio collar stopped sending signals 18 months ago. Forest officials neither cared to replace nor remove it.
Chief wildlife warden U. M. Sahai said the National Tiger Conservation Authority (NTCA) has asked the Wildlife Institute of India to send a doctor to tranquilise the tigress to remove the collar. But the doctor was on leave.
Ironically, Jaipur zoo doctor Arvind Mathur was very much available and he has the experience of successfully tranquilising around 10 tigers in the past.
Wildlife enthusiast Dhirendra Godha said the collar could be a possible reason for the full-grown adult tigress not breeding.
NTCA expert Rajpal Singh seconded Godha’s views. He said T17′ s sister, T19, who is not collared gave birth to three cubs around six months ago.
A similar situation prevailed in Sarika too. None of the three tigresses have been able to reproduce and experts have not detected any hormonal imbalance, which affects their fertility.
Apart from the radio collars, disturbances from the two highways bisecting the reserve, the stress of being shifted from Ranthambhore and acclimatising with a new environment could be the other factors for the sterility.
Rajpal Singh said samples have been sent to the Hyderabad-based National Centre for Biological Sciences to test if there were any biological reason.
Experts, including Godha, said the common factor between T17 and the Sariska tigresses was the radio collar. They agreed that there was no scientific evidence to prove the collar could be an impediment, but it needed to be explored.
State’s principal chief wildlife warden R. N. Mehrotra said his department was contemplating doing away with the collars once and for all because these “infringe upon the privacy of the tigers”.