Feeding strategies of Elaphe longissima from contrasting Mediterranean habitats in central Italy

Abstract

A 17‐year study on the diet composition of the snake Elaphe longissima was carried out in three contrasting Mediterranean habitats in central Italy: an agro‐forest habitat, a thick forest habitat, and a bushy pasture habitat. In the agro‐forest area, the snake diet consisted only of small mammals and lacertid lizards, but in the other two areas also of birds and their eggs. There were significant differences of prey eaten by snakes among habitats: a UPGMA tree diagram clustered the agro‐forest and the thick forest habitats, whereas the bushy pasture habitat proved to be very different from the other two. Lizards were preyed mainly in the agro‐forest habitat. Species of the family Muridae (and in particular the wood mice Apodemus sp.) were preyed upon considerably more frequently than Microtidae in all habitats. Among the birds, only some species of the order Passeriformes were preyed upon, and among the reptiles, wall lizards Podarcis muralis were preyed upon more frequently than any other species. Diet composition was similar in males and females. There was a positive relationship between log‐transformed prey size (mass, in g) and predator size (mass, in g) in all the studied habitats, and the regression lines relative to the various habitats did not differ significantly in terms either of slope or elevation. A model of ANOVA treatment revealed that the snakes of the three habitat types were similar both in terms of absolute body size (mass in g) and residuals of the ‘predator size‐prey size’ regressions.