Nidificação da andorinha azul-e-branca (Pygochelidon cyanoleuca) em ambiente urbano do Sudeste do Brasil

Pygochelidon cyanoleuca is a common species, but little is known about its biology and life history in the urban environment of southeastern Brazil. The objective of this study was to monitor the reproduction of the species in this environment. We determined the total number of nests, nesting peak, construction site, shape, composition and distribution pattern of nests, and the success and possible causes of reproductive failure. The study was conducted between July and December 2007, in the hall of the library of the Federal University of Uberlândia in Uberlândia, Minas Gerais, Brazil. Nests were screened in spinning gutters and fixtures in the ceiling of the hall. We found 33 nests, of which 31 were active. Two nesting peaks were observed (August and November). Most nests had a platform shape. The pattern of distribution was aggregate. 19.4% of the nests were successful. The causes of failure were predation and unviable eggs. Pygochelidon cyanoleuca was reasonably successful and was able to make use of the structure of the roof of the library to build its nests. However, the high frequency of unviable eggs underscores the importance of studies on the potential effects of urbanization on birds and other organisms of the Cerrado and other Brazilian regions.