COMPARISON OF DIET AND USE OF BROMELIADS BETWEEN A BROMELICOLOUS AND A BROMELIGENOUS ANURAN AT AN INSELBERG IN THE SOUTHEASTERN OF BRAZIL

Résumé 0

Anurans from an inselberg in southeastern Brazil were studied using a sample of sixty tank bromeliads Alcantharea sp. We found 153 tadpoles of S. arduous, 21 adults of S. arduous, 30 adults of T. miliaris, and two individuals of Scinax x-signatus, which were not considered in our analyses. Tadpoles of S. arduous were present in 35% of the analyzed plants. Adults of S. arduous (bromeligeneous) occurred in 25% of analyzed plants, while adults of T. miliaris (bromelicolous) occurred in 30%. Apparently the presence of toe pads in S. arduous allows them to occupy the center portion of bromeliads, while T. miliaris, which do not have pads on their toes, used the base of the plant axils for residency. The number of anuran species and the abundance of individuals found were low. This may be a result of the high altitude of our studied site or a restriction imposed by the saxicolous environment, such as high temperatures and low humidity during the day. Both species can be considered generalist feeders due to their wide variety of ingested prey. Formicidae was their main prey but was absent inside the bromeliads. Blattodea was very common inside the bromeliad axils and represented the most significant prey by weight in both frog species. We can conclude that both anurans forage inside and outside of bromeliads. The trophic niche breadth in S. arduous was larger than in T. miliaris. Even though both species are common inhabitants of the same environment, they demonstrated a marked spatial segregation in the bromeliads. Based on their diet, however, there may be disputes for territory outside of the bromeliads.