Importance of Native Grassland Habitat for Den-Site Selection of Indian Foxes in a Fragmented Landscape

Ravi Chellam,Abi Tamim Vanak,Girish Arjun Punjabi

doi:10.1371/journal.pone.0076410

Abstract

Fragmentation of native habitats is now a ubiquitous phenomenon affecting wildlife at various scales. We examined selection of den-sites (n = 26) by Indian foxes (Vulpes bengalensis) in a highly modified short-grassland landscape in central India (Jan-May, 2010). At the scale of the home-range, defined by an 800 m circular buffer around den sites, we examined the effect of land-cover edges and roads on selection of sites for denning using a distance-based approach. At the smaller den-area scale, defined by a 25 m x 25 m plot around den and paired available sites, the effect of microhabitat characteristics was examined using discrete-choice models. Indian foxes selected den-sites closer to native grasslands (t = -9.57, P < 0.001) and roads (t = -2.04, P = 0.05) than random at the home-range scale. At the smaller scale, abundance of rodents and higher visibility increased the odds of selection of a site by eight and four times respectively, indicating resource availability and predator avoidance to be important considerations for foxes. Indian foxes largely chose to den in human-made structures, indicated by the proportion of dens found in earthen bunds (0.69) and boulder piles (0.27) in the study area. With agricultural expansion and human modification threatening native short-grassland habitats, their conservation and effective management in human-dominated landscapes will benefit the Indian fox. The presence of some human-made structures within native grasslands would also be beneficial for this den-dependent species. We suggest future studies examine the impact of fragmentation and connectivity of grasslands on survival and reproductive success of the Indian fox.

Highlights

Habitat modification and fragmentation are recognized globally as important drivers of biodiversity loss [1,2]
We examined the effect of den substrate, visibility, shrub density, and rodent burrows by using discrete choice models [17]
We found a total of 26 active Indian fox breeding dens in the study area from January to April 2010

Summary

Introduction

Habitat modification and fragmentation are recognized globally as important drivers of biodiversity loss [1,2]. Human modification and fragmentation create landscape heterogeneity in native habitats and may threaten species by deterministic and stochastic processes [2]. Studies indicate that species’ responses to human modification are dependent upon the ecology of the species involved, the amount of habitat change, and the rate at which species adapt to changes in their environments [3,4,5,6]. In India, the tropical short grassland plains [7] are a fragmented mosaic of native grasslands and humanmodified areas. Short grassland ecosystems across the country are only a peripheral focus of conservation attention, and there has been considerable fragmentation and alteration of these grasslands through intense agriculture and industrialization [7]. Few studies have quantitatively assessed species’ responses to modification in such systems [8]

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