Sexual dimorphism and dietary composition of the sandfish lizard Scincus scincus (Linnaeus, 1758) of southeastern Algeria

In this study, we present the first data on the sexual dimorphism and diet of a typical desert lizard species, Scincus scincus, in the region of El-Oued, southeastern Algeria. The objective was to characterize the types of prey in the diet and determine whether there is a correlation between prey size and body size in males and females. The results obtained reveal that out of the 115 individuals captured (43 males and 72 females), sexual dimorphism is observed. Males tend to be larger than females, with males exhibiting relatively larger snout-vent length, head height, head length, and jaw length compared to females. However, no difference is recorded in terms of head width. The analysis of stomach contents allowed us to identify 485 prey items distributed among 9 prey categories, all attributed to insects. Coleoptera was the most commonly ingested prey category, accounting for 61.54% of stomachs, 59.79% of total prey items, and 62.41% of total volume. A similar diet was observed between females and males of S. scincus, with a high diet overlap (O = 0.99) and a low diversity of prey types ingested by both males (Ba = 0.17) and females (Ba = 0.19). Coleoptera represented the most dominant order in the skink's diet, followed by the Hymenoptera order. Generally, the remaining seven taxa were consumed in low proportions by both sexes. Additionally, we observed no significant difference between the number of prey consumed and the volume of prey between the sexes, and no correlation was found between morphometric characteristics, diet composition, and prey volume.