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And Now, the Birdcast

Passing almost unnoticed in the night, billions of birds will fly over the mid-Atlantic states this spring on their annual migration northward. A new Web site will help ornithologists pinpoint critical habitat for the feathered travelers by combining weather radar data with old-fashioned fieldwork.

Radar has been used to track bird migrations since around 1940, says Steve Kelling, who heads BirdSource, a bird database at Cornell University. But the potential payoff grew about 5 years ago when the government began installing Doppler radar Stations, which yield high-resolution threedimensional data. Ornithologists are eager to use Doppler to track bird movement, but first, they need to calibrate it with data from the ground.

So Cornell, Clemson University, and other groups have launched BirdCast. Every few hours from April to 31 May, radar images of the Philadelphia to Washington, D. C., area – some filtered to remove weather and reveal birds – will be posted on the project’s Web site (www.birdcast.org). The site will also collect observations from several hundred citizen-scientists (birdwatchers, that is), which will be combined with other data, such as chirps picked up by acoustic monitors. Kelling says the results should reveal the bird’s favorite rest stops,

highlighting priority areas for protection. Eventually, BirdCast hopes to go nationwide.

SCIENCE Vol 288 7 April 2000

Os termos “weather”, em “weather radar data” ; “heads”, em “who heads BirdSource” ; e “rest”, em “bird’s favorite rest stops” têm, respectivamente, as funções gramaticais de