Bird species in rainforest fragments in Brazil that were isolated by deforestation disappeared then reappeared over a quarter-century, according to research results published today in the journal PLoS ONE.
Scientists thought many of the birds had gone extinct.
The research was funded by the National Science Foundation (NSF), and conducted in cooperation with Projeto Dinmica Biolgica de Fragmentos Florestais, Instituto Nacional de Pesquisas da Amaznia and the Smithsonian Tropical Research Institute in Manaus, Brazil.
Lead author Philip Stouffer, an ornithologist at Louisiana State University and co-authors of the paper--Erik Johnson at the National Audubon Society; Richard Bierregaard at the University of North Carolina, Charlotte; and Thomas Lovejoy at The Heinz Center in Washington, D.C.--measured bird populations over 25 years in 11 forest fragments ranging from 2.5 acres to 250 acres in the Amazon rainforest near Manaus, Brazil.
In the first decade of the long-term study, birds abandoned forest fragments and, ornithologists believed, went extinct. Then in the past 20 years, many bird species returned, while others went extinct or remained extinct.
"Through long-term observations of fragmentation in tropical forests, this study provides verification that local extinction is accompanied by continual recolonization, dependent on habitat size," said Saran Twombly, program director in NSF's Division of Environmental Biology, which funded the research.
Although species loss following habitat changes can be inferred, long-term observations are necessary to accurately identify the fate of bird populations, said Stouffer.
As the project began, bird populations were tracked before the forests were cut.
During the first year after cutting, bird species disappeared in what the researchers call "localized extinction," meaning a species has disappeared from a particular area.
|Contact: Cheryl Dybas|
National Science Foundation