Availability peak of caloric fruits coincides with energy-demanding seasons for resident and non-breeding birds in restinga, an ecosystem related to the Atlantic forest, Brazil

Abstract

We evaluated temporal variation and quality of food resources available to birds especially in two energy-demanding seasons: one when there is a peak of molting residents and another when non-breeding individuals are the bulk of biomass of captured birds. Birds were captured and observed, as well as fruits counted and collected, in two restinga sites for 2 years. Molting resident birds may rely basically on the regularly produced Clusia hilariana and Erythroxylum spp. fruits as lipid-sources, while non-breeders count on Ocotea notata fruits (also rich in lipids) during their passage by the study site. We found that fruits with sugars, lipids or proteins were available throughout the whole period, but a more intense seasonal variation was observed for the before mentioned plant species. The birds studied are known to be potential seed dispersers of these plant species, which are important components of restinga plant community structure.