West Nile Virus Decimates Suburban Birds
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By SETH BORENSTEIN AP Science Writer
May 16,2007 | WASHINGTON -- Birds that once flourished in suburban
skies, including robins, bluebirds and crows, have been devastated by
West Nile virus, a study found.
Populations of seven species have had dramatic declines across the
continent since West Nile emerged in the United States in 1999,
according to a first-of-its-kind study. The research, to be published
Thursday by the journal Nature, compared 26 years of bird breeding
surveys to quantify what had been known anecdotally.
"We're seeing a serious impact," said study co-author Marm Kilpatrick, a
senior research scientist at the Consortium of Conservation Medicine in
New York.
West Nile virus, which is spread by mosquito bites, has infected 23,974
people in confirmed cases since 1999, killing 962, according to the
Centers for Disease Control and Prevention.
But the disease, primarily an avian virus, has been far deadlier for
birds. The death toll for crows and jays is easily in the hundreds of
thousands, based on the number dead bodies found and extrapolated for
what wasn't reported, Kilpatrick said.
It hit the seven species -- American crow, blue jay, tufted titmouse,
American robin, house wren, chickadee and Eastern bluebird -- hard
enough to be scientifically significant. Only the blue jay and house
wren bounced back, in 2005.
The hardest-hit species has been the American crow. Nationwide, about
one-third of crows have been killed by West Nile, said study lead author
Shannon LaDeau, a research scientist at the Smithsonian Migratory Bird
Center in Washington. The species was on the rise until 1999.
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