Inter-population and seasonal changes in food habits of the Moroccan Spiny-tailed lizard along an aridity gradient

Abstract

Abstract Food habits of the Moroccan Spiny-tailed lizard, Uromastyx nigriventris, from three localities along an aridity gradient from north-east (Mediterranean) to southwest (Atlantic pre-Saharan) of the Atlas range, Morocco, were investigated in spring and autumn 2015 using fecal microhistological analysis. The obtained results showed that these lizards are predominantly herbivorous feeding on 4 to 13 different plant species depending on locality and season, but some insects, namely coleopterans and ants (Formicidae) (up to 6%) are also consumed. They heavily ingested annual and perennial herbaceous plants through a single season. There were significant differences among seasons and localities in terms of species richness and Shannon-Wiener diversity indexes. These indexes increased significantly, respectively for the spring and autumnal diets, and correlatively with the species richness in the habitat along the aridity gradient. The Stress-Gradient Hypothesis could explain this increase. According to Pianka’s niche overlap index (), dietary overlap was low between Saka (the least arid locality) and Skoura (the intermediate locality) in spring. Conversely, there was a substantial overlap in the diets in autumn with a more pronounced similarity between Saka and Skoura. A review of published information on food habits among Spiny-tailed lizard species and populations was established.