Bird mortality due to collisions in glass panes on an Important Bird Area of southeastern Brazil

Abstract

Human-caused alterations to the environment are important causes of the loss of bird biodiversity globally. Collisions with windows are the second leading human cause of mortality for birds, and it is estimated that 100 million to a billion birds die due to window collisions annually in the US alone. However, in Brazil there have been no systematic studies on bird mortality due to collisions with man-made structures. Our aims with this study were to record the bird species that died due to collisions with windows in an Important Bird Area of southeastern Brazil, accessing the effects of species characteristics (forest dependence, wing type, threaten status, endemism, migratory habits) and climatic seasonality on bird-window collisions. Dead birds were collected daily during 2010 to 2013 and occasional records were obtained from 2000-2009 and 2014-2015 in Reserva Particular do Patrimônio Natural Santuário do Caraça, Minas Gerais, southeastern Brazil. We found 168 birds individuals of 57 species dead due to collisions against windows. Individuals classified as forest dependent and with elliptical type wings were the most common among the birds dead due to collisions. There was no difference between the number of dead individuals in the dry and rainy seasons, and rainfall was not correlated with bird collisions. The occurrence of threatened, endemic and migrant species in our sample demonstrates the importance to continue this type of research in Brazil and other localities throughout the Neotropics. Our data can support works that investigate the influence of other factors and characteristics of natural history of bird collisions, particularly in areas with similar man-made structures as at our study site.