Why? Because, the tigers in Sariska are stressed out! A field study on Sariska tigers spanning nearly two years has come up with findings that explain how human population concentrated in the park is leading to high levels of stress in the cats and is altering their behavioural pattern.

The findings underline that Sariska tigers are in stress and the stress pattern is more accentuated in females than in male tigers. This could be one of the reasons why tigers took painfully long to reproduce in Sariska reserve.

The revelation has been made by senior scientists of three different institutes — the Laboratory for the Conservation of Endangered species (LaCONES), CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Wildlife Institute of India (WII) Dehradun and Endocrine Research Laboratory, Department of Anatomy and Physiology, University of Pretoria, South Africa. Together the scientists of these institutes conducted the study to understand the Glucocorticoid Stress Responses of the reintroduced tigers in relation to anthropogenic (human) disturbance.

The research findings reveal, "Female tigers were more sensitive to disturbance than males. The researchers found that tiger's fGCM levels were significantly positively related to the time spent in disturbed areas translating into the overall low breeding success in Sariska tiger reserve."

Even conservationists believe that human activities have exerted pressure on the wild animals resulting in low breeding. "Even though Sariska is the biggest tiger reserve of state, the wildlife is fragmented due to human activities in the forest. If one goes through the census in pre-2005 wipeout at Sariska,one can find that breeding activities had hit a low and there were no new cubs in the park. During those years, the human activities in the park were at its peak," says Tejveer Singh, retired IFS official, who managed Sariska as a District Forest Officer (DFO).

Conservationists point out that "inviolate space" is needed for tigers to multiply. "Tigers were reintroduced in Panna Tiger Reserve after Sariska and yet Panna holds more tigers than Sariska. Even tigresses at Ranthambhore give birth to cubs regularly. The common factor between Panna and Ranthambhore is the inviolate space and negligent anthropogenic activities inside the park which is completely missing in Sariska," says a forest official requesting anonymity.

Interestingly, 32 villages, of which ten are in the notified national park area, with a combined population of around ten thousand humans live inside the Sariska Tiger Reserve dependent on pastoral activities, in addition to the nearly twenty thousand livestock owned by the people.

Talking to dna on the findings, field director of Sariska tiger reserve, Raghuvir Singh Shekhawat said, "Yes there is a huge anthropogenic pressure on Sariska and its tigers. This pressure is increasing with each passing day.

Due to the pressure, tigers and wildlife is affected negatively. However the park management is taking every step to ensure that the pressure is eased out." He added, recently, the vehicular movement inside the park was restricted and a bus service was started to ease the pressure created by movement of vehicles."

How the field study was carried out

A non-invasive approach to monitor faecal glucorticoid metabolite (fGCM) concentrations in the reintroduced tigers was used over a period of 18 months collecting a total of 120 faecal samples. Moreover, the scientists estimated various anthropogenic disturbance variables and determined tiger movement pattern using radio collars. They have correlated individual fGCM concentrations with various anthropogenic factors including encounter rate with human and cattle