Morphological correlates of prey consumed by Podarcis melisellensis (Braun, 1877) and P. siculus (Rafinesque, 1810) (Sauria, Lacertidae) from two mainland regions in the eastern Adriatic area

Abstract

The correlation between trophic utilization and morphology was studied for two lizard species (Podarcis melisellensis and P. siculus) from two mainland localities in the eastern Adriatic area; this is the first report of trophic and morphometric data for P. melisellensis from mainland populations. Variance partitioning showed that most of the variation in morphological traits for the analyzed lizards was the result of differences between species, and to a lesser extent between sexes. Locality did not have a strong effect on the variation of morphological traits. Prey weight is the only characteristic of prey that generally exhibits correlations with morphological characteristics rather than prey size. The pattern of correlations is generally weaker for P. melisellensis than for P. siculus. Optimal foraging theory predictions were generally confirmed: P. siculus is more constrained by trophic resource availability, with a premium on larger and heavier prey consumed in the less productive locality (SM), which can be relaxed in more productive regions (KL). P. melisellensis shows such constraints only for males in the less productive region (SM). Females of both species consume heavier prey.