Distribution, Habitat Use and Threats to Otters in Corbett Tiger Reserve
 - Asghar Nawab, Senior Research Fellow

Distribution, habitat use, and threats to smooth-coated otter Lutra perspicillata were studied in and around the Corbett Tiger Reserve during 2001 and 2004. Of the six perennial water bodies surveyed, presence of otter was recorded in three rivers viz. Ramganga, Mandal and Palain that are relatively undisturbed and support potential microhabitats for otters. Proportional occurrence of otter signs in Ramganga, Mandal and Palain rivers were 17.5%; (n=80 plots), 15%; (n=40 plots) and 13.75%; (n=80 plots) respectively, and there was no evidence of otters from Rivers Sonanadi (n=20 plots), Kosi (n=80 plots) and the reservoir area (n=80 plots). A total of 8.15%; (n=380 plots) positive sites were identified over the whole study period and accounted for 774 otter signs, the most common being spraints 64.47%; (n=499 spraints) followed by tracksets 17.05%; (n=132 tracksets). Four otter groups were identified in the study area with group size ranging from 4 to 16 (mean=5.13 ±1.55). Based on logistic regression, microhabitat variables such as water current, water depth, water quality and prey were identified to determine otter occurrence (classification accuracy = 98.12%). Intensive use areas were delineated from the presence of dens; through high levels of sprainting and grooming sites. Disturbance due to human presence along the riverbanks was evident in areas that lay close to the vicinity of the reserve boundary. Besides habitat deterioration, poaching of otter and its prey (fish) were the major threats identified. The current status of otters in Corbett Tiger Reserve is encouraging though they are vulnerable to stochastic and anthropogenic disturbances. The conservation of otter in the region is discussed in light of the results of the analysis.
 

Dr. S.A. Hussain