Variation in feeding ecology of five cnemidophorine species along Brazilian eastern coast

Abstract

Feeding ecology of a particular species is associated to population dynamics and contributes for the understanding of natural history and trophic interactions in ecosystems. We investigated changes in the feeding habits of 16 populations belonging to five cnemidophorine species (being four bisexual and one unisexual) along approximately 4000 km of the Brazilian eastern coast. Fieldwork was carried out in 15 areas of restinga habitats along approximately 4000 km of the Brazilian eastern coast. For each cnemidophorine population, the composition of the diet was based on the number, volume (mm 3 ) and frequency of each prey category.The arthropods were categorized in the taxonomic level of Order or Family (e.g.Formicidae). Cnemidophorine populations/species studied were mainly carnivorous and had, in general, a diet consisting predominantly of larvae and/or termites, with few consumptions of plant material. The availability of termites in the restinga habitats was not a determinant factor in the increase of termite consumption by these lizards. However, differences in diet composition among populations partially resulted from differential consumption of termites, leading to the formation of two distinct groups depending on higher or lesser consumption of termites. Some populations had onthonegetic variation, but males and females of different populations/species tended to have similar diet composition. The head width size of lizard affected significantly the volume and the length of the largest prey ingested in 60% (3/5) of the species studied, indicating that adults tend to consume larger food items than juveniles.The high level of importance of termites and larvae in almost all populations/species probably contributed to the low intra-and interspecific differences in food habit. The diet of cnemidophorine species studied in restinga habitats, in general, tend to be similar to that found to other cnemidophorines, regardless its geographic distribution. Invertebrates were the predominant prey on cnemidophorines diet, but predation on vertebrates was also reported.