Abstract
In the present study a total 16 groups o hanuman Langurs (Semnopithecus entellus), including 11 unimale bisexual troops and five all male bands with a populaiton of 540 animals, were observed at Kumbhalagarh Wildlife Sanctuary in the Aravalli Hills. They were studied for their group size, composition , sex ratio, etc. For this three focal troops BS-2, BS-5 and BS-10 were observed in three different eco-systems. The mean troop size was 41.7 (range 19 to 113) and the mean band size was 15.6 (range 8 to 32). The adult male - female sex ratio comes to 1:4.6 in the study area.