Occupancy estimation and modeling in monitoring tigers with implications for conservation and management

Abstract

The tiger (Panthera tigris) is highly endangered through out its range and one of the impediments to effective tiger conservation is the lack of simple and cost effective methods for monitoring of wild tiger populations. With an aim to find a rapid, cost effective, and statistically robust methodology to take quick management decisions, observations of tiger and co-predator sign in administrative subunits (beats) of the Similipal Tiger Reserve, located between 200 28’ and 220 08’ North latitude, and 860 04’ and 860 37’ East longitude in India, were subjected to an occupancy estimation and modeling analysis. Several environmental factors were identified as covariates with explanatory power for the pattern of observations of tiger sign. Most important of these were the proportion of the area of the beat that is classified as disturbed habitat, the distance between the beat and the nearest inhabited place, and the total number of prey observed in the beat in a separate set of surveys for ungulates and other tiger prey species. The results of this analysis have clear management implications for the reserve, with beats classifiable into four categories, each with its own target strategy for increasing tiger abundance. These categories are: highest concern, reduce disturbance, increase prey protection, and maintain current protection. This study suggests that occupancy estimation and modeling from surveys of large mammalian predator sign is a simple cost-effective statistically robust methodology that can be performed by the management staff of a reserve and can be used to engage members of the local population in conservation.