For the past five centuries, humans have pushed nearly 500 bird species to extinction, according to a report by the Proceedings of the National Academy of Sciences. The report predicts that the extinction rate will increase during the 21st century.
Peter Raven, president of the Missouri Botanical Gardens and co-principal author of the report, adds that habitat destruction, selective hunting, invasive alien species and global warming are some of the causes adversely affecting the natural populations of plants and animals.
Since the major period of European global exploration and colonization, birds are becoming extinct at a rate of one species per year, or 100 times faster than the natural rate, the researchers calculated.
“What our study does, for the first time, is provide a well-justified and careful estimate of how much faster bird species are going extinct now than they did before humans began altering their environments,” said Stuart Pimm, professor of conservation ecology at Duke University’s Nicholas School of Environment and Earth Sciences and co-principal author of the report. His research group was the first to determine how to estimate extinction rates.
The research team determined most of their calculations from a Bird Life International database of threatened and endangered species.
The report does offer some positive words. “Conservation efforts are reducing extinction rates to about one bird species every three or four years,” said Pimm.
Continued conservation efforts, however, might not prevent the extinction of 1,200 more species that are likely to disappear in the 21st century, according to Pimm. “An equal number are so rare that they will need special protection or likely go extinct, too.”
The report appeared in an online edition of the Proceedings of the National Academy of Science in July 2006.