Distinguishing sex of free-ranging tigers using pugmark measurements

Monitoring the sex ratio of elusive species, including tigers (Panthera tigris tigris Linnaeus, 1758), is an important aspect of population management and conservation. We collected 45 pugmarks made by the left hind foot pads of two adult male and seven adult female tigers in the core area of Ranthambhore Tiger Reserve (RTR), India. We used linear and shape-based variables to develop a discriminant function model that distinguishes the sex of adult tigers using pugmarks. The accuracy of sex determination of male and female tigers using total length and total width was 87.5%. Using only the variable area of the pad, which is significantly different in male and female tigers, the sex of tigers could be distinguished accurately (100%). Our technique will facilitate the acquisition of sex-ratio data and the development of protocols for carrying out regional surveys and monitoring tiger populations in areas where pugmarks are easy to obtain.