Food Availability and range use by the common langur (Presbytis entellus) in Rajaji National Park, U.P. India

Abstract

A bisexual group of Common langur (P. entellus) wan chosen in Rajaji national Park, (U.P. India) to tent my hypothesis that spatial variation in the intensity of use -of home range is correlated with food availability. During the study period T collected data at three levels: (i) 6-day group scan for activity patterns, occupational density and frequency of use of major food species items. (ii) Circular plots, covering 6 percent of the area for estimating availability of tree species. (iii) Phenological data for estimating monthly variation in food items. Using the latter two I calculated the availability of major food species item spatially and temporally. I found that occupational density was significantly correlated with the availability of major food items in only two months. When analyzed for five months correlation increased as more major food items were added. The correlation was not significant for December, February and March because of constraints in the estimation of food availability added to the problem of dumpiness and rarity in the distribution of food species. A linear correlation is however, unlikely because availability of most foliage is often in excess of immediate requirement. moreover, as summer progressed water increasingly became limiting factor. This, in combination with other factors like inter-group interactions might further decrease the possibility of getting a linear correlation.