Biogeographic patterns in the feeding habits of the opportunist and semiaquatic Neotropical otter

Abstract

We evaluated the biogeographic factors that influence composition and diversity of the Neotropical otter diet. We also tested whether Lontra longicaudis selected fish in its diet per their availability. We collected data from 41 studies, covering most of the otter’s distribution, 32 of which had prey identified to family level. Fish was the main prey for L. longicaudis throughout the species range. However, its frequency was higher in sites farther from the coast and at higher slopes. Alternative prey items compensate the decrease in fish. Temperature seasonality, slope, and distance to coast were the most important factors determining the diversity of the otter’s diet. Populations in areas with more variation in temperature and/or closer to the coast showed a more diverse diet with an increase of alternative prey. Trophic diversity was positively correlated with temperature seasonality but negatively correlated with the slope and distance to coast. As an opportunist, semiaquatic predator with a wide distribution range, L. longicaudis has a flexible diet, and this plasticity might be explained by the wide range of habitats occupied by otters. Furthermore, Neotropical otter diet was also found to be more similar in geographically closer areas, as well as in similar environment types.