Resource utilization and parental investment in the Indian for (Vulpes bengalensis) in Kutch, Gujarat

Abstract

I studied the resource utilization patterns in the Indian fox (Vulpes bengalensis) with respect to diet in Kutch, Gujarat. Resource use and availability by foxes were compared between two habitats and between two seasons. Resource availability was quantified through transects laid in both the habitats for the different prey items: mainly mammals, birds, reptiles, arthropods and fruits. Resource availability differed in both the habitats as well as across seasons (summer and winter). Density of fruiting shrubs (particularly Zizyphus) and gerbil burrows were significantly different between the two habitats. Gerbil population mean obtained from different colonies trapped during the study period showed a significant relationship with the total number of burrows in the colony (R2 =0.969). Scats collected from den sites were used to quantify resource use of the Indian fox. The minimum number of scats that can be used to estimate the annual food habits of the Indian fox in' a dry arid area like Kutch is about 110 scats. Frequency of occurrence of prey species also differed across habitat and seasons. The food habits of the Indian fox comprised of varied items, mainly arthropods like beetles, orthopterans, scorpions and termites. Among the other items, rodents, hares, spiny tailed lizards, birds and eggshells as well as fruits have been found. Arthropods were the most frequently occurring prey items (75% and above), among them particularly the termites. They are seen to be selected more than availability within the habitat. This was indicated by the three methods used to compare use versus availability (Ivlev's Index, Bonferroni's CI, and Compositional Analysis). However the Indian fox is seen to maximize energy requirements by selecting gerbils next in the preference after arthropods being selected more than availability during most cases within the habitat. Density of breeding units evaluated in the scrubland showed a density of 0.1 O/sq Ian. The density of breeding pairs obtained in this particular study was much higher as compared to the ones reported earlier for Kutch (0.04-0.06/sq Ian) due to good rainfall in the preceding two years thereby indicating a good prey base as compared to other years.