Cape Wind tracks birds

ON HORSESHOE SHOAL - Jeffrey Burm had just begun to explain why he has spent much of the spring on a platform barge, nine miles from the shore.
 
Suddenly, a bird swooped out of the fog and off the boat's railing. Burm, binoculars dangling from his neck, broke off his sentence and jerked his head to get a better look.
 
''Sorry,'' he apologized, before instinctively identifying the bird. ''That was an immature harbor gannet.''
 
Burm is a biologist, but for about six weeks he has also been a professional bird-watcher of sorts for Cape Wind Associates, the developer that wants to build a wind farm on these waters.
 
Before Cape Wind can build turbines on the sound, it first must prove to skeptics - and the state - that, among other things, the 417-foot-tall towers won't harm birds.
 
A scientific team hired by the developer is completing a six-week, $400,000 radar study of the sound to characterize just how many birds fly through this offshore location - and, critically, at what heights.
 
For the second time, the developer is using sophisticated radar during springtime on Horseshoe Shoal itself. It's a time when winter songbirds arrive from the warmth of South America and hundreds of thousands of ducks also pass through.
 
The experts call it the right research at the right time since it is the spring migration.
 
It was also required by the state Executive Office of Environmental Affairs as part of its review of the ambitious and controversial offshore proposal.
 
Supporters hope the results, which won't be known for months, will also satisfy some of the conditions imposed by the Massachusetts Audubon Society.
 
While the society has offered preliminary support for the project after years of research.
 
Jack Clarke, director of public policy and government relations for Massachusetts Audubon, says there are still some gaps in bird data on the sound.
 
In particular, they want to know more about the nighttime patterns of long-tailed ducks on the sound; the trends of endangered terns and threatened plovers; and just how many songbirds are flying through the area and where they are passing.
 
For the most part, the Audubon Society has concluded that terns and plovers typically avoid the area where the 130 turbines would be built. And the songbirds tend to fly thousands of feet above the water, high above the proposed towers.
 
Cape Wind has already conducted three radar studies to follow bird patterns.
 
But critics have complained that results from two of the studies were questionable since they were collected at remote, land-based sites.
 
The U.S. Fish and Wildlife Service, for instance, has urged three years of radar study before a conclusion can be drawn.
 
''What is still missing is the continuous radar monitoring,'' agreed Susan Nickerson, executive director of the Alliance to Protect Nantucket Sound, which opposes the Cape Wind project.
 
This time around, at least two scientists constantly staff the 72-foot barge, which stands on three 75-foot legs.
 
Twenty-four hours a day for six weeks, two powerful radars turn continuously. One scans the horizon over Nantucket Sound over a distance of four miles. The other stares up into the sky to a height of 10,000 feet.
 
Eventually, the data will be sorted to draw patterns and numbers that Cape Wind hopes will be the clearest picture yet on the sound as a springtime habitat.
 
The researchers are collecting about 2 gigabytes of information per day, said David Pitts, a field biologist for Geo-Marine Inc., which has provided this service for European wind farms and military projects.
 
''It's a smart time to be here,'' Burm says. ''And the right place.''
 
Kevin Dennehy can be reached at kdennehy@capecodonline.com.