Ecologia de Tropidurus torquatus (Wied, 1820) (Squamata: Tropiduridae) na Reserva Biológica de Comboios, municípios de Linhares e Aracruz, ES

Abstract

Tropidurus torquatus (Wied, 1820) is a widely-distributed lizard species, typical of open habitats, occurring from north-central Brazil to northern Argentina. The aim of this study was to evaluate the morphometry, thermal ecology, diet, reproduction and ectoparasitism of lizards from a restinga population at Reserva Biológica de Comboios, Espírito Santo state, Brazil, and the potential effect of seasonality on these aspects. We collected 62 lizards during the rainy season (November/2013) and 60 in the dry season (September/2014). The local availability of prey itens was estimated. Males were larger in body, head and jaw sizes. No significant differences were found in the frequency of occurrence of caudal autotomy between sexes, adults and juveniles, and reproductive and non-reproductive females. The mean body temperature in activity varied from 34 to 36C and differed significantly between sexes in the rainy season, but there was no significant difference in the dry season. The air and substrate temperatures influenced body temperature, but air temperature explained an additional part of body temperature variation in the dry season. Body size did not influence the body temperatures of lizards. Adult lizards had an omnivorous diet, composed predominantly by insects and some vegetal matter. There was one record of inter-specific predation. Juveniles had a carnivorous diet composed mainly by insects. Formicidae was the most important item in the diet of both adults and juveniles. The number of ingested items had no relationship with lizard body size, but item volume was influenced by jaw size. The diet of adults reflected the local availability of items in terms of volume but not in number. For juveniles, there was no correlation between diet composition and items availability. The number of items consumed by lizards was significantly higher in the rainy season, but there was no seasonal variation in the volume of prey ingested. Among the 63 females collected in total, 41 were reproductive. The mean clutch size was two eggs and was not influenced by either female body size nor egg size. The most important sites of infestation by the mite Eutrombicula alfreddugesi (Trombiculidae) were the joints and skin folds, especially mite pockets. The mite s prevalence was 100% and the intensity of infestation was higher in males. Intensity of infestation was influenced by lizard body size. Seasonal variation in the number of mites was recorded only for males, being higher in the rainy season. Tropidurus torquatus from Restinga de Comboios has sexual dimorphism and low frequencies of caudal autotomy. Mean body temperature in activity is influenced by substrate and air temperatures, especially air temperature in the dry season. It is a sedentary forager with an omnivorous diet, predominantly insectivorous, which reflects the availability of items in the environment. Mean clutch size is almost fixed in two eggs and is not influenced by female body size. All lizards are infested by E. alfreddugesi mites and joints and skin folds are the preferred microhabitat, with males being more infested, mainly during the rainy season.