RESOURCE PARTITIONING IN A MEDITERRANEAN LIZARD COMMUNITY

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