Tigers in Core Protected Zones Show Higher Stress Levels Due to Tourism

Tigers in core zones of major Indian reserves show significantly elevated stress hormone levels when exposed to tourism and human activity, according to a two-year study by scientists at the CSIR–Centre for Cellular and Molecular Biology (CCMB) in Hyderabad. The findings, based on 610 genetically confirmed tiger scat samples collected from 2020 to 2023 across five reserves, reveal that tigers in protected core areas like Tadoba and Bandhavgarh are more physiologically stressed than those in buffer zones with regular human presence.

Researchers measured faecal glucocorticoid metabolites as a stress indicator and found consistently higher levels in tigers near tourism roads and in high-disturbance zones across Corbett, Tadoba–Andhari, Kanha, Bandhavgarh and Periyar reserves. Tigresses, in particular, showed reduced reproductive hormone levels in stressed environments, raising concerns about breeding success and cub development. Chief scientist G. Umapathy said quiet forest areas essential for breeding are increasingly scarce.

The study does not oppose tourism but calls for science-based regulation, including limiting vehicle numbers, shortening safari hours, reducing road density, and protecting identified breeding zones. Scientists recommend creating water sources away from tourist routes and using non-invasive monitoring to track tigress movements. The findings were published in the Zoological Society of London’s journal Animal Conservation.

CSIR-CCMB Director Dr. Vinay Nandicoori said the study demonstrates how molecular biology can inform conservation policy. The research was supported by the Science and Engineering Research Board, with permissions from the National Tiger Conservation Authority and state forest departments. The National Tiger Conservation Authority is expected to review the recommendations for potential integration into reserve management protocols.