Análise da biologia reprodutiva, vulnerabilidade a contaminantes químicos e a bactérias patogênicas de Larus dominicanus Lichtenstein, 1823 (Aves, Laridae) no litoral de Santa Catarina, Brasil

Abstract

The gull Larus dominicanus is a common shorebird in south and southeast of Brazil. Being opportunistic regarding the occupation of habitats and type of food, can expand their populations. After the reproductive period occupies beaches, estuaries and mangroves, where they feed and spend part of their life cycle. Aspects involving the reproductive biology of this species have been studied in this state, requiring update for the proper management. However, there are still gaps on exposure to chemical and microbiological contaminants, and how these variables could influence the populations of the species. The objective of this thesis was to analyze the association of L. dominicanus to the pathogenic bacteria, their vulnerability to heavy metals and aspects of reproductive biology in three breeding sites, located on the coast of Santa Catarina. In the first chapter cloacal samples of young gulls were analyzed, indicating the presence of harmful microrganisms. In this article, we discuss the diversity of bacteria isolated from samples obtained in the islands, as well as its relationship with the feeding habit of this birds. The second chapter is about the analysis of heavy metal contamination in young gulls feathers. The results showed contamination by lead in two of the three islands studied. There is evidence that L. dominicanus is in process of bioaccumulation of metals, arising from the exploration of coal, developed near to the study areas. The third chapter compares reproductive aspects of gulls, as hatching success, posture, volume of eggs and offspring development. No differences were observed when comparing the reproduction between the islands, and the data were similar to those reported by other authors. Considering the three articles, it appears that L. dominicanus acts as a reservoir of pathogenic bacteria, and is vulnerable to contamination by heavy metals of anthropogenic origin, and no evidence of change in reproductive success and population dynamics of species.