Amphibian and Reptile Consumption by Otters (Lutra Lutra) in a Coastal Area in Southern Iberian Peninsula

Abstract

Through the analysis of 1518 otter spraints we determined the importance of amphibians and reptiles in otter diet and the seasonal patterns of consumption of the different species in a heterogeneous coastal environment in southern Spain. Otters fed on a minimum of six amphibian and three reptile species. Amphibians were present in 13.2% and reptiles in 3.9% of the spraints analysed. Remains of amphibians and reptiles were significantly associated in otter spraints, but negatively associated with crayfish occurrences. Maximum reptile consumption occurred during the summer. Though terrapins have been rarely cited as otter prey, they were consumed more than twice as frequently as water snakes in the study area. The highest frequency of amphibians in the otter diet was recorded in late winter-spring surveys, coinciding with the spawning periods of most species. However, the frequency of amphibians remained high during summer months due to predation on the Iberian green frog (Rana perezi), a very aquatic frog that was almost the only amphibian species consumed in this season