Diet and Trophic Niche Overlap of Three Toad Species (Amphibia, Anura) from Poland

ABSTRACT

During our study we identified 53 prey items in the trophic spectrum of Bombina bombina, 124 prey items in the diet of Bufo bufo and 95 prey items in the diet of Epidalea viridis. The average number of prey items per stomach is as follows: Bombina bombina - 7.57, Bufo bufo - 9.0 and Epidalea viridis - 13.57. In all studied species the most important prey category is Coleoptera. Other important prey animals are Hemiptera, Hymenoptera and Dermaptera as well as non-insect invertebrates (Gastropoda and Arachnida) which also play significant role. All toads consume almost only terrestrial prey. The trophic niche breadths for the three species are as follows: Bombina bombina - 5.40, Bufo bufo - 4.47 and Epidalea viridis - 2.42. The estimated trophic niche overlap between the species is moderate (58.82% - 63.72%) and probably there is no or insignificant competition for food resources between them in the places with sympatric distribution. All studied species are polyphagous zoophages, like other amphibian species and they are probably consuming all mobile objects which they come in contact with and can swallow.

Keywords:

• trophic spectrum
• niche overlap
• Bombina bombina
• Bufo bufo
• Epidalea viridis
• Poland