Comparative Data on the Trophic Spectrum of Syntopic Bombina variegata and Rana temporaria (Amphibia: Anura) Populations from the Iezer Mountains, Romania

In August 2009, we compared the trophic spectrum of syntopic Bombina variegata and Rana temporaria populations from the Bratia Valley in the Iezer Mountains. The separation of the trophic niche observed between the juveniles and the adults of R. temporaria is caused by the differences in size between them, differences that influence their jump. The main consumed prey taxa by Rana temporaria is represented by Arahnida, Gastropoda and Hymenoptera. Furthermore, the differences between the sizes of their mouths separate the trophic niche between the two species. Our results indicate a trophic selectiveness for B. variegata, which prefers ants. Despite the fact that the two species share the same habitat, the ants were consumed mostly by B. variegata. This is probably a consequence of the fact that B. variegata is a poisonous species, the toxins being able to originate from their preys – as are ants - as well. The lack of competition for the two species indicates a rich trophic offer, enough to satisfy the energy needs of both species in contact in a limited space.