Prey selection by smooth-coated otter (Lutrogale perspicillata) in response to the variation in fish abundance in Upper Gangetic Plains, India

• Published in: Mammalia (Paris) Vol. 76; no. 1; pp. 57 - 67
• Main Authors: Nawab, Asghar, Hussain, Syed Ainul
• Format: Journal Article
• Language: English
• Published: Walter de Gruyter 01.02.2012
• Subjects: corbett tiger reserve; mustelids; prey selection; river ecosystems; smooth-coated otter
• ISSN: 0025-1461; 1864-1547
• DOI: 10.1515/mamm.2011.105

The dietary diversity of carnivores often varies inversely with prey abundance. Slight environmental perturbations, anthropogenic or otherwise, leading to lower prey availability, could affect the continued existence of mammalian carnivores in human-dominated landscapes. We examined the selection of prey by the smooth-coated otter in response to the variations in abundance of fish in Corbett Tiger Reserve in the Upper Gangetic Plains, India. Sixteen fish species were recorded from the Reserve; 14 from the lotic and five from lentic systems. In the lotic systems, the river cat (Glyptothorax pectinopterus) was most abundant during summer followed by ticto barb (Puntius ticto) and mahseer (Tor spp.), while during winter mahseer was most abundant followed by chaguni (Chagunius chagunio) and minnow (Labeo dyocheilus). The diet of otter included four prey categories, among which fish were the most dominant prey (84%). The other preys were amphibians, crabs and birds which were taken occasionally. There was no difference in the overall proportion of different prey categories utilized among seasons and sites. In the Reserve, eight fish species from the families Cyprinidae and Sisoridae were used. The ticto barb, chaguni, minnow and river cat were the most utilized species. The species used and their preference by otters varied from river to river depending on their availability in different seasons. The ticto barb was most utilized during summer, followed by river cat and hill trout. In winter river cat, chaguni and mahseer were the most utilized species. The otters used hill trout (Barilius bendelisis), sucker head (Schizothorax richardsonii) and ticto barb during summer and chaguni and minnow during winter more than their availability, indicating their preference.