RESOURCE PARTITIONING IN A MEDITERRANEAN LIZARD COMMUNITY

Some aspects of community ecology in a lizard assemblage composed of t hree sympatric and diurnal species (Algyroides fitzingeri, Podarcis ti liguerta, Chalcides ocellatus) were studied in a Mediterranean habitat of central Sardinia. The three lizards were characterized by signific antly different mean body size. There was no spatial overlap between t he smallest species (A. fitzingeri) and the largest one (C. ocellatus) , while there was a certain amount of overlap between P. tiliguerta an d each of the other two lizards. The three species preyed on a wide va riety of invertebrates, but mainly on insects. Food niche breadth was higher in P tiliguerta, and this could be related to the higher microh abitat heterogeneity of this lizard in the study area. Food niche over lap was high between Chalcides ocellatus and Podarcis tiliguerta, but low between Algyroides fitzingeri and C. ocellatus. Although further d ata are required before any firm conclusion can be drawn, the results of this investigation seem to indicate that (i) interspecific competit ion among the three lizards is rather limited, due both to food and sp atial resource partitioning, and (ii) the lizard community is organize d through the ecological needs of each species.