Sariska Tiger Sanctuary (STR) in Rajasthan's Alwar is facing unusually slow multiplication of the big cat population mainly due to large scale miscarriages suffered by its tigresses.

Tiger re-introduction programme, first of its kind in the world, was taken up in the sanctuary in 2008 as there were no tigers in 2004 due to large scale poaching.

"All five adult tigresses of Sariska have suffered 22 miscarriages so far," K.L. Saini, vice president of Sariska Tiger Foundation told Mail Today. Saini, a retired officer of the Indian Forest Service (IFS), also served as field director of the sanctuary during 1984-89 when 39 tigers roared in Sariska.

Currently there are 13 tigers in the sanctuary, including four cubs, two male and seven female tigers. Ever since the tiger, coded ST-1, was killed by poisoning, the sanctuary is facing gender imbalance.

This is more so as all the six cubs- born in Sariska have been fathered by ST-4. Only two tigresses ST-2 and ST-10 have given birth so far. ST-2 gave birth to two cubs each in 2011 and 2014 while ST-10 gave birth to two cubs in 2014.

It was in this background that tiger expert Dhirendra Godha asserted that immediate need for Sariska was a potential male tiger. But Saini maintains even that could not help as the main cause for miscarriages and non-breeding was the radio collar put around the neck of tigresses that hinders their mating process.

Supporting Saini's argument, Sunayan Sharma, a former field director of Sariska who also served there between 2008-09 when the reintroduction programme was taken up, asserted in his just published book, "I feel that the tigers brought from Ranthambhore are more sensitive to radio collars than those of Kanha and Bandhavgarh, reintroduced in Panna Tiger Reserve (Madhya Pradesh) after the Sariska experiment. I reiterate that the radio collars should be removed from reintroduced tigers as soon as they are settled in their new homes."

Referring to the Panna experiment, Saini pointed out that, unlike Panna where tigresses having proven fertility were relocated, in Sariska 'virgins' were translocated and they found it difficult to sexually readjust to the new environment.

However, dismissing these arguments, Rajasthan's former principal chief wildlife warden R.N. Mehrotra asserted that the main reason for non-breeding or inadequate breeding and several miscarriages was the large scale human interference in the tiger habitat.