Ecologia de Phimosus infsuscatus (Aves: Threskiornithidae) no litoral de Santa Catarina, Brasil

Abstract

Phimosus infuscatus is a bird of gregarious behavior found in South America. Despite its conspicuity, few studies involve the species, so that a large gap exists on its ecology. There is, for example, no in-depth information on abundance in feeding areas, habitat selection, behavioral repertoire, roost use, daily dispersal movements, breeding and morphology of chicks. Thus, this study was developed aiming to verify the species abundance and habitat selection in foraging areas in three municipalities in the coast of Santa Catarina, presenting and discussing its behavioral repertoire; to analyze daily movements between feeding areas and a roost discovered in the municipality of Itajaí, SC; and to evaluate its reproduction during two seasons in two areas located in the city, with information on nest building, incubation, parental care, success estimates and morphology of nests, eggs and chicks. The research used binoculars, measuring equipment, meteorological databases, CEMAVE metallic rings for chick marking spreadsheets for data recording and computer software for organization, analysis and textual production. The abundance was related to the rice cultivation cycle in the region, mainly during soil preparation and inundation, and the reproductive period. The foraging was carried out preferentially in slightly flooded and low vegetation environments, with no major preferences between aquatic or terrestrial arthropods available as resource supplies, with food searching behavior considered the default. The roost was used continuously for two years, with daily movements of groups up to dozens of individuals and population fluctuation varying in the same way as the abundance quoted above. The species used rivers margins in two different models during its reproduction, with success as expected for the family, and better conditions in the second season, observed in the measurements of eggs and chicks, which allowed the definition of growth stages of the last. This study brings brand new information and serves for a better ecological understanding of the species, being able to contribute to preservation and management strategies, care of individuals in captivity and future research, also helping to understand the fast population expansion of the species in Santa Catarina.