Feeding ecology of the endangered Apennine Yellow-bellied Toad (Bombina pachypus) in central Italy

Abstract

Anurans are generalist opportunistic consumers, but many species show some degree of diet specialization. Within populations, individuals may specialize in specific dietary resources (individual specialization). Indeed, generalist populations may be composed of individuals using the whole range of available resources or of diverse individuals exploiting specific food items. Based on the niche variation hypothesis (NHV), an increase in population niche width may be related to a higher incidence of individual specialization. We analyzed the feeding ecology of the endangered Apennine Yellow-bellied Toad ( Bombina pachypus (Bonaparte, 1838)) in central Italy. This species showed a generalist feeding strategy, wide trophic niche, high individual generalization, and a predominant use of terrestrial resources. The study species inhabits seasonal habitats determining variation in food availability and diversity, and this may have driven toads to be unselective and consume almost any encountered palatable item. The absence of sexual size dimorphism may explain the absence of trophic differentiation between sexes. The analysis of individual feeding traits revealed a week's degree of individual specialization positively correlated to niche width, partly supporting the NHV. The obtained information can be used for the implementation of effective conservation strategies of locally imperilled species, especially those breeding in temporary ponds.