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, three-dimensional data. Ornithologists are eager to use Doppler to track bird movements, but first, they need to calibrate it with data from the ground.
So Cornell, Clemson University, and others have launched BirdCast. Every few hours from 1 April to 31 May, Doppler radar images of the Philadelphia to Washington, D.C., area will be posted on the project's Web site (www.birdcast.org ). Some images are filtered to remove the effects of weather, Kelling says, "so we can look at what's important, which is the birds." The site also expects to collect observations from several hundred citizen-scientists--birdwatchers, that is. The sightings will be combined with other data, such as chirps picked up by acoustic monitors. And each day a weather-based forecast will let birdwatchers know whether birds are likely to migrate that night.
Kelling says the results should reveal the birds' favorite rest stops, highlighting priority areas for protection. Eventually, BirdCast hopes to go nationwide.