Feeding Habits of the River Otter in a Reservoir in Central Massachusetts

Abstract

From 1955 to 1957, 517 scats of otter (Lutra canadensis) were collected throughout the seasons from a reservoir in central Massachusetts, where availability of different fish species was known from netting and poisoning. Observations of otters fishing and analysis of scats indicated these mammals preyed chiefly on warmwater fishes inhabiting coves. In order of frequency of occurrence, various centrarchids were found in 54% of the scats, followed by yellow perch, white suckers and golden shiner. In spite of high populations of salmonids (lake trout, brown trout and rainbow trout) there was no evidence of prédation on these species. Frequency of occurrence in scats varied significantly with seasons. Otters were found to feed frequently on blueberries in late summer, and among invertebrate prey species crayfish were consumed at all seasons and occurred in 56% of the scats.