Breeding ecology of Nyctanassa violacea, Egretta thula and Egretta caerulea nesting grounds in the Pedreira River, Santa Catarina State

Abstract

This study aimed to characterize the Pedreira River breeding colony of wading birds and to estimate the breeding success of the species in this area. The study area included the mangrove in the Pedreira River, located next to the port of São Francisco do Sul harbor. Surveys were made weekly during the reproductive cycle of the birds, starting in August 2011 and ending in March of 2012. A total of 210 nests were recorded, which included 60 of Nyctanassa violacea and 150 of Egretta spp. The colony began in late winter and ended in early fall, with greater activity occurring between September and December. Hatching success was very similar between the species, with 49% for N. violacea and 50% for Egretta spp. The survival rate of the pups was higher for N. violacea with 32%, compared with Egretta spp. with 24% survival.

Keywords

• Breeding success
• Colonial Breeding
• Survival