HYDERABAD: A study by scientists at CSIR-Centre for Cellular and Molecular Biology has found that tourism and human activity inside tiger reserves are increasing stress among tigers and influencing where tigresses choose to breed, raising concerns over the long-term health of India’s big cat population. Researchers, however, stressed that tourism management must become more science-based rather than restricted altogether.
Published in the journal Animal Conservation, the study tracked tigers across five reserves over two years and four seasons, making it among the largest multi-reserve physiological assessments conducted on wild tigers in India.
The research covered Corbett, Tadoba-Andhari, Kanha, Bandhavgarh and Periyar tiger reserves.
“We analysed 610 genetically confirmed tiger scat samples collected between 2020 and 2023, including samples from 291 females and 185 males. The team measured stress hormones and reproductive hormone markers to understand how human disturbances affect tiger behaviour and breeding patterns,” lead author Dr G Umapathy told the TNIE.
The study found that tigers living close to tourism roads and areas with heavy human disturbance showed consistently higher stress hormone levels. Tigers inside core forest zones also displayed sharper stress responses to tourism activity than those in buffer zones.
According to researchers, tigers in buffer zones appear to have become habituated to continuous human presence, while tigers in core areas experience sudden stress spikes when seasonal tourism enters otherwise quieter habitats. The impact was particularly visible in Tadoba and Bandhavgarh.
“Tigresses prefer to breed in quiet parts of forests. However, it’s becoming difficult to find such suitable areas,” Dr Umapathy said.
He added that prolonged stress could reduce reproductive success and affect cub development. “In Tadoba and Corbett, the buffer zones already have high tiger populations. It is concerning if the core areas also become stressful for tigresses,” he said.
Dr Vinay Nandicoori, director of CSIR-CCMB, said the findings showed how molecular biology and physiology could directly aid wildlife conservation.
The researchers clarified that the study does not oppose wildlife tourism, noting that it supports conservation funding and rural livelihoods. They recommended stricter regulation of safari vehicle numbers, prevention of vehicle crowding during tiger sightings, shorter safari durations and improved management of buffer zones in heavily disturbed reserves.