Spatial and trophic resource partitioning among an insectivorous lizard community in the central Jbilet mountains (Western Marocco)

Spatial and trophic resource partitioning among seven sympatric insectivoro us lizard species was investigated in arid area in the central Jbilet mount ains (Western Morocco) during spring 1995. Two foraging guilds are apparent : a specialist sit-and-wait (Agama impalearis, Tarentola mauritanica et Sau rodactylus brosseti) and a generalist one (Eumeces algeriensis, Chalcides p olylepis, Acanthodactylus erythrurus and Mesalina simoni). The studied liza rd species differentiate from each other in substrate use relatively to the ir respective adaptive morphological traits. A. impalearis and T. mauritani ca occur mainly in rocky areas, E. algeriensis and M. simoni appear mostly on rocky and pebbly-bare ground substrates, A. erythrurus and C. polylepis are found on sandy-pebbly substrates while S. brosseti occurs in pebbly soi ls. By contrast, there were large overlaps in the taxonomic composition of their diets which are numerically dominated by Formicidae, Isoptera, Coleop tera and Araneidae with different proportions according to lizard species. However, important prey-size differences between species allowed to reduce trophic overlap. A selectivity analysis of lizard diet revealed patterns of prey selection based on criteria inherent either to predator (foraging beh aviour, morphological constraints) or prey (size, abundance and activity). Results suggest that spatial and trophic segregation along with taxonomic d ivergence make possible the coexistence of these lizard species.