FEEDING HABITS OF A MEDITERRANEAN COMMUNITY OF SNAKES IN RELATION TO PREY AVAILABILITY

Dario Capizzi*, Luca Luiselli**, Massimo Capula**, Lorenzo Rugiero***

Introduction

Relationships between snakes and their prey have been studied in detail by several authors (Mushinsky, 1987). Most predictive studies on such issue come from North-American assemblages of species, essentially with aquatic or semi-aquatic habits (for a recent review, see Mushinsky, 1987). Conversely, feeding ecology of most western European snakes is known by essentially detailed lists of the prey items found in snake stomachs and faeces (e.g. see Saint Girons, 1980, 1983 ; Bea & Brana, 1988 ; Brana et ai, 1988 ; Monney, 1990 ; Pleguezuelos & Moreno, 1990 ; Luiselli & Agrimi, 1991, Bea et al, 1992 ; Luiselli & Rugiero, 1993).

The kernel conviction generated from the complex of studies of snake community ecology is that these organisms, contrary to most of other vertebrates, do not partition the habitat resource but the available food resource (e.g. see Mushinsky & Hebrard, 1977 ; Luiselli & Rugiero, 1991). However, the occurrence of food partitioning has never been tested in assemblages of terrestrial snakes of Mediterranean habitats, despite such habitats are frequently characterized by (i) remarkable snake species diversity (Corsetti & Capula, 1992) and (ii) high prey species diversity (especially lizards and small mammals) (Canova & Fasola, 1993).

In this paper we test (1) whether the same trophic resource is used by different species in a community of terrestrial sympatric snakes, (2) whether a food partitioning does exist, and (3) whether the snake species feed upon their prey in relation to the relative prey availability in the environment.

Materials and methods

Study area and the species

Data given here were entirely collected in a locality situated about 15 km north-east of Rome, central Italy (Settebagni, about 20-100 m a.s.l. ; 42° 03’ N,

Rev. Ecol. (Terre Vie), vol. 50, 1995.

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