Dieta de aves em uma área de Mata Atlântica no sudeste do Brasil

Abstract

Não informado pelo autor.The study of trophic ecology may clarify important issues related to seasonality of resources and bird responses in abundance and diversity, which depends on their behavioral and/or ecological adaptations. Birds have behavioral and morphological adaptations for optimum foraging, and there are many gaps on the knowledge on the diet of Neotropical birds, despite its recent advances. Our goal in this study is to assess the diet of birds in the Carlos Botelho State Park/SP, an area of Atlantic Forest in southeastern Brazil, verifying the occurrence of seasonality in diet and abundance of different trophic guilds, and testing whether the items found in fecal samples were related to the gape width of birds and investigate if the diet and abundance varied seasonality. We captured 700 birds from June 2012 to May 2013, including 135 recaptures from 30 species, being five threatened by extinction. We collected 189 samples of 35 bird species, composed by fecal, regurgitation and stomach analyses, in which we identified 11 groups of invertebrates, with a predominance of Coleoptera, one vertebrate and 24 types of seeds, with a prevalence of Melastomataceae. Chamaeza campanisona had the first record of vertebrate (Amphibia, Anura) in its diet. Captured birds were divided into five trophic guilds (insectivores, omnivores, frugivores, nectarivores and piscivores), and we found no relation between bird capture rates and rainfall temperature and no variation in abundance of birds throughout the year as well. Six bird species had their prey size estimated, and Lanio melanops, Turdus albicollis and Philydor atricapillus had the larger consumed items, and P. temminckii the least; seasonal variation in diet was observed only for L. melanops. The size of invertebrates were correlated to the gape width of birds for six species, suggesting that there would be few competition for prey among them, considering prey size and foraging substrate. The method of fecal analysis was useful for describing food items of birds, corroborating the existing literature both in classification of trophic guilds and for composition of food items.