Deciphering the Chemical Dossiers Left Behind by India’s Big Cats

The methodology, published in the Journal of Chemical Ecology, marks a transition toward volatilomics—the study of chemical signals released by organisms. By employing ultra-sensitive thermal desorption gas chromatography mass spectrometry, the team identified specific markers, such as the compound 2-nonanol, which spikes in pregnant or lactating tigresses. This provides a non-invasive, cost-effective alternative to traditional tracking methods like pugmark counting or camera trapping, which often fail to capture physiological health data.

Lead researcher BV Aditi Prasad spent months gathering samples from captive animals in Bengaluru, Ahmedabad, and Vadodara, alongside wild specimens in Rajasthan’s Ranthambore Tiger Reserve. The team observed that scent marks serve as detailed territorial postcards. Unlike camera traps, which require the animal to be physically present and visible, these chemical signatures persist in the environment for days. This allows field teams to gather data even when the cats remain hidden within dense vegetation.

While India currently maintains the world’s largest tiger population—reaching 3,167 individuals in the 2022 assessment—monitoring their health remains a logistical challenge. Supervising author Shannon Olsson suggests this technique could eventually extend to detecting diseases, as evidenced by a preliminary observation of elevated dimethyl tetrasulphide in a captive tiger treated for epilepsy. Senior author Uma Ramakrishnan notes that while the project currently focuses on tigers and leopards, the simplicity of the sampling process makes it highly adaptable for monitoring other threatened species, including snow leopards, wolves, and bears, potentially revolutionizing how conservationists assess the viability of endangered wildlife populations globally.