Temporal variation in diet and helminth abundance in the spiny-tailed lizard, Strobilurus torquatus Wiegmann, 1834 (Squamata: Tropiduridae) from the Brazilian Atlantic Forest

Spatial and temporal variations can influence the abundance and biology of parasite species and even the transmission process, as well as the diet, reproduction and distribution of hosts. We studied the influence of seasonality on the diet and endoparasites of the lizard Strobilurus torquatus. The lizards were collected during a period of one year, in the  Engenho Gargaú Private Reserve of Natural Heritage, located in the municipality of Santa Rita, in the state of Paraíba, Northeast Brazil. Thirty-three lizards were analysed, of which 30 were parasitised (overall prevalence of 90%) with the helminths Physaloptera lutzi (prevalence of 69.6%), Spauligodon loboi (51.5%), Strongyluris oscari (15.1%) and Haplometroides odhneri (3.0%). Our analysis showed that endoparasite abundance was influenced by host body size (R2m: 0.95; R2c: 0.95; Z-value: 11.521; P < 0.0001). Host sex also influenced endoparasite abundance, where males were parasitised more than females (Z-value: 6.260; P < 0.001). When comparing the two seasons (dry and rainy), we observed that the greatest  endoparasites abundance occurred during the rainy season (Z- value: -2.422; P < 0.05). Regarding the lizards’ diet, we observed a high niche overlap (overlap index of 0.999), which indicates that males and females of S. torquatus consumed practically the same prey during the analysed period. The life cycle of the endoparasites found in S. torquatus was linked to seasonal variation, and the behavioural and physiological differences between sexes may have influenced the variations in endoparasite abundance.