Sex-identification Technique and Sex-ratio in Tiger: Doubts and Clarifications

Abstract

The hind pugmarks of female Tiger fit into a rectangle while that of a male Tiger fit into a "biological square" whose length and width may not be equal. For adult females with pugmark longer than 11.0cm the length-width difference is more than 1.5cm. A ready reckoner has been provided to compare length-breadth dimensions and ascertain the sex of Tiger from hind pugmarks. The idea of using the breadth alone for sex-identification has been dismissed because of limitations. The sex ratio oftiger at birth is 1:1. It changes in favour of reproducing females because genetic-depression and ecological cost do not favour natural selection in maintaining males longer or in large numbers in a closed population. The census figures from different Tiger populations may present different sex ratios because of local factors and also the extent of inclusion of "pre-breading" or "post breading" Tigers which remain peripheral to the main breeding population. It is urged that wildlife techniques should ideally emerge from the wild because of distorted behaviour as well as morphometrics known to occur with animals under protracted captivity. It is further urged that application of statistical principles to biological thoughts should be in a language intelligible to field biologists.