BURROW USE PATTERNS BY TERRESTRIAL VERTEBRATES IN KEOLADEO NATIONAL PARK, BHARATPUR, INDIA

Abstract

Most animals use some refuge either daily or seasonally. Burrow in terrestrial habitats is one of the oldest forms of engineered shelters (Voorhies, 1974) reported as early as carboniferous period (Olsen and Bolles, 1975). Burrows appear to be crucial refuge especially in arid and semi-arid regions providing protection against temperature extremes, fire and predation (Campbell and Clark, 1981; Reichman and Smith, 1990). Three major categories of burrowing vertebrates have been identified by Kinlaw (1999). These include ‘primary excavators’ for whom digging burrows is an inevitable part of their survival; ‘secondary modifiers’ that occupy and further transform the burrows of primary excavators and the third category of ‘simple dwellers’ that take advantage of the mere existence of the burrows and occupy them. Burrow inhabitants are even reported to be either in obligate and/or non-obligate commensal associations (Kiviat, 1978; Kinlaw, 1999). Burrowing vertebrates are the potential ecosystem engineers. These organisms have the capability of modifying habitats and directly or indirectly regulate resource availability for other species (Hansell, 1993; Jones et al., 1994; Lynn and Detling, 2008). They are known to have positive and negative effects on the ecosystem, species richness and abundance at small scales, but an overall positive effect at larger scales in ecological and evolutionary time and space (Jones et al., 1997). In Negev desert, Israel, the digging behavior of porcupine Hystrix indica has been studied as a model of disturbance and recovery of plant species (Gutterman et al., 1990). The burrows are important for newborn porcupines for their survival (decrease in vulnerability), energy conservation and thermoregulation