Tuesday, July 04, 2006

Birds and Extinctions

There is news on new studies of avian extinctions. One study focused on the general topic, the other on its most famous example.

Stuart Pimm's team reports in the Proceedings of the National Academy of Sciences that we have approximately 10,000 known bird species and 130 known examples of extinction, most concerning Pacific island birds. Pimm warns, though, that we are undercounting extinctions, in part due to overlooking the new examples of extinct species being identified from fossil and subfossil remains. He calculates the rate of bird extinctions may be about one species per year. For what it's worth, that rate, says Pimm, would have tripled if not for recent bird conservation efforts.

Meanwhile, there's news about the most famous symbol of extinction caused by human activity, the dodo bird of Mauritius. Scientists studying the largest cache of dodo remains ever found report the population took a severe hit from a natural disaster long before humans got there in the 16th century. A cyclone and/or flood created a disaster that left the dodo population in a precarious state. Humans are still guilty of the final execution of the species, but it's important to understand all the factors involved in any extinction, and now we have a much clearer picture of this one.

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