Tourism and human activity hurting tiger breeding in India's 5 major reserves: CSIR-CCMB study
Synopsis
A first-of-its-kind hormone study spanning five Indian tiger reserves reveals that tourism is not just disturbing tigers — it is suppressing their breeding. More strikingly, core zones meant to be sanctuaries are showing higher stress spikes than buffer zones, upending a foundational assumption of tiger conservation in India.
Key Takeaways
CSIR-CCMB scientists analysed 610 genetically confirmed tiger scat samples from five reserves across India between 2020 and 2023 .
Tigers near tourism roads showed consistently elevated stress hormones , with breeding activity in tigresses also negatively affected.
Counterintuitively, core-zone tigers showed higher stress responses to human disturbance than buffer-zone tigers, who appear habituated to year-round human presence.
The stress effect was most pronounced in Tadoba and Bandhavgarh .
Researchers recommend reducing safari durations by one hour per session, capping tourist vehicle numbers, and continuously monitoring tigresses to protect breeding hotspots .
Findings are intended to inform the National Tiger Conservation Authority (NTCA) and state forest departments.
Tourism and human activity are pushing tigers in India's major tiger reserves into chronic stress and disrupting their breeding cycles, according to a landmark new study by scientists at the CSIR-Centre for Cellular and Molecular Biology (CSIR-CCMB), Hyderabad. Published in the Zoological Society of London journal Animal Conservation, the research is the first to combine non-invasive stress and reproductive hormone analyses from tigers across five major Indian tiger reserves, offering the most comprehensive physiological portrait of wild tigers under human pressure to date.
What the Study Examined
The research team analysed 610 genetically confirmed tiger scat samples — including 291 from females and 185 from males — collected between 2020 and 2023. Scientists tracked tigers across different parts of India through four seasons over two years, covering reserves at Corbett (Uttarakhand), Tadoba–Andhari (Maharashtra), Kanha and Bandhavgarh (Madhya Pradesh), and Periyar (Kerala).
Two key hormone markers were measured: faecal glucocorticoid metabolites, a biomarker of stress, and faecal progesterone metabolites, an indicator of breeding activity in females. Across all five reserves, tigers ranging close to tourism roads and in areas with greater human disturbance consistently showed elevated stress hormone levels.
A Counterintuitive Finding on Core Zones
One of the study's most striking conclusions challenges a long-held conservation assumption: tigers in strictly protected core zones showed a higher stress response to human-caused disturbance than those living in multi-use buffer zones. The effect was most pronounced in Tadoba and Bandhavgarh.
Researchers attribute this to habituation — buffer-zone tigers are exposed to year-round human presence and appear to have adjusted, whereas core-zone tigers register sharp stress spikes when seasonal tourism enters these otherwise quieter areas. This finding directly challenges the assumption that core zones are uniformly low-stress refuges for wildlife.
What Scientists Said
Dr G. Umapathy, Chief Scientist at CSIR-CCMB and lead researcher on the project, said:
Point of View
Grounding the long-running tourism-stress debate in hard hormone data. The counterintuitive core-zone finding is particularly significant: if the areas designated as the strictest refuges are actually triggering sharper stress responses than buffer zones, then the entire zoning logic of India's tiger reserve management warrants re-examination. The National Tiger Conservation Authority has historically resisted hard caps on tourism, citing revenue and community livelihood arguments. This study gives regulators a scientific basis they can no longer easily dismiss — but whether it translates into enforceable policy or remains another well-cited paper in a long queue is the real test.
NationPress
9 May 2026
Frequently Asked Questions
What did the CSIR-CCMB tiger study find?
The study found that tourism and human activity are causing elevated stress hormone levels in tigers across five major Indian reserves, and that this stress is negatively affecting breeding activity in tigresses. It is the first study to combine non-invasive stress and reproductive hormone analyses from tigers across multiple Indian reserves simultaneously.
Which tiger reserves were included in the study?
The study covered five reserves: Corbett in Uttarakhand, Tadoba–Andhari in Maharashtra, Kanha and Bandhavgarh in Madhya Pradesh, and Periyar in Kerala. Scat samples were collected over two years between 2020 and 2023.
Why are core zones showing higher stress than buffer zones?
Buffer-zone tigers appear to have habituated to year-round human presence, while core-zone tigers — accustomed to quieter conditions — register sharp stress spikes when seasonal tourism enters. This challenges the assumption that core zones are uniformly low-stress refuges for tigers.
What management changes does the study recommend?
The study recommends capping tourist vehicle numbers, preventing crowding at tiger sightings, reducing safari durations by approximately one hour in both morning and evening sessions, creating water bodies away from tourism routes, and continuously monitoring tigresses to identify and protect breeding hotspots.
Is the study arguing for a ban on wildlife tourism?
No. Lead researcher Dr G. Umapathy explicitly stated the study is not against wildlife tourism, which supports conservation funding and rural livelihoods. The recommendation is for science-informed regulation of vehicle numbers, safari timings, and road density rather than an outright ban.
