Reproductive Dynamics of Sterna hirundinacea Lesson, 1831 in Ilha dos Cardos, Santa Catarina, Brazil.

Hélio Augusto Alves Fracasso,João Pedro Barreiros,Joaquim Olinto Branco,Márcio Amorim Efe

doi:10.1155/2014/907549

Abstract

In this work, we intend to describe the reproductive dynamics of Sterna hirundinacea in an island from South Brazil. We studied the reproductive biology of this species in its natural environment and provide data on their growth, survival, and reproductive success in Ilha dos Cardos, Santa Catarina, South Brazil. Samplings were carried out daily on the island throughout the reproductive seasons of 2003, 2005, and 2006 and the different stages of development of the chicks were characterized according to age, length of the beak, and plumage characteristics. We provide a basic equation Lm = 167.91 (1 − e −0.062t−(−0.23)) to determine the approximate age of individuals using their body mass. The main cause of chick mortality on the island was natural (63.17% in 2003, 81.41% in 2005, and 79.96% in 2006), whereas predation contributed to mortality in a proportion of 38.83% in 2003, 18.59% in 2005, and 20.04% in 2006. The absence in the area of the chicks' main predator, Kelp gull (Larus dominicanus), the large number of chicks that reached the final stages of development, and their reproductive success demonstrate that Ilha dos Cardos is an important breeding site for the species in southern Brazil.

Highlights

The South American Tern, Sterna hirundinacea Lesson, 1831, is distributed in the Atlantic coast of South America, from southeastern Brazil to Tierra del Fuego in Argentina/Chile, including the Falkland Islands and the Pacific coast to southern Peru [1, 2], with one record for riverine environments in Rio Negro, Argentina [3].The species is almost exclusively coastal, nesting on sandy or rocky beaches, cliffs, and small islands [4]
We investigated the reproductive biology of the South American Tern in its natural environment, with the objective of giving information on growth, survival, and reproductive success of a population breeding in Cardos Island following the pioneering work of Branco [6]
Juvenile I (JI) corresponded to the hatchlings usually found in the nest, with the “egg tooth” (Figure 3) and Ltbeak average 1, 23 ± 0.01 cm between 1 and 6 days, with yellow-cream plumage throughout the body (Figure 3)

Summary

Introduction

The species is almost exclusively coastal, nesting on sandy or rocky beaches, cliffs, and small islands [4]. In the Brazilian coasts, nests are found in coastal islands from Santa Catarina [5, 6] to Espırito Santo [7], from April to August, usually in sympatry with Cabot’s Tern, Thalasseus acuflavidus (Cabot, 1847) [6, 8, 9]. According to Nisbet et al [15], differences in the growth patterns of chicks have been used to explore parental performance variations, whereas differences in mean parameters of colony growth over the years have been used to explore differences in average environmental conditions. It is known that the postnatal development of seabirds can be a sensitive indicator of local environmental

Methods

Results

Conclusion