Feeding Ecology and Morphometric Variation of Varanus griseus (Varanidae: Squamata ) (Daudin, 1803) in the Northeastern Algerian Sahara

Saharan ecosystems harbor a remarkable diversity of reptiles that have evolved unique adaptations to survive under extreme environmental conditions. Among them, the desert monitor, Varanus griseus (Daudin, 1803), is an important predator within desert food webs. However, information on its trophic ecology in the Algerian Sahara remains scarce.

The present study aimed to characterize the diet and describe the main morphometric parameters of Varanus griseus in the Souf region, northeastern Algerian Sahara. Field investigations were conducted between June and September 2019, during which twelve specimens were collected. In Varanus griseus, the results of morphometric measurements showed that there is a high positive correlation between LT and LQ (R = 0.890; P < 0.001) and a low positive correlation between LT and LC (R = 0.755; P < 0.01). However, the relationship between LQ and LC was not significant (R = 0.373; P > 0.05). Trophic diversity was evaluated using the Shannon diversity index (3,73 bits) and Pielou’s evenness index (0,91).

The Morphometric analyses revealed proportional growth among the measured body dimensions. Stomach content analysis showed that insects constituted the dominant prey category (76.47%), followed by reptiles (11.77%), whereas mammals and arachnids each accounted for 5.88% of the diet. The ecological indices indicated relatively high trophic diversity and a balanced distribution of prey categories, highlighting the opportunistic feeding strategy of V. griseus, with a clear predominance of insect prey in the Saharan environment.

This study provides new insights into the trophic ecology of Varanus griseus in the Algerian Sahara and improves our understanding of its ecological role in desert ecosystems. These findings also provide valuable baseline information for future ecological and conservation studies on this species in arid environments.