Island birders track mating habits for state's database
BY PETER B. BRACE INDEPENDENT WRITER
If a male and female catbird so much as fly around together and act like they are a couple, Nantucket's birding cognoscenti will log their existence and behavior. The same goes for any other bird species on Nantucket that courts, nests and produces eggs over the next three years.

The original atlas, published in 2003, contains distribution maps showing possible, probable or confirmed breeding records for Massachusetts' nesting species on a grid of 989 blocks.

The sharp lookout is part of the "Breeding Bird Atlas 2" being compiled by the Massachusetts Audubon Society and bird organizations in Vermont, New York, Pennsylvania, Maryland, Washington, D.C., Ohio and Ontario, Canada, and will form a data set from these contiguous states. It will be used to compare information gathered for the first "Breeding Bird Atlas" to show changes where birds are breeding in these states and provinces.

"The reason for doing this is to just plot the distribution of breeding birds throughout the state," said Dr. Bob Kennedy, Director of Natural Science for the Maria Mitchell Association. "It gives us an idea of changing bird breeding habitats throughout the state. As global warming happens, some species are going to be moving out of the state and some species are going to be moving into the state and this is the way to track the changes."

Since Mass Audubon completed its first "Breeding Bird Atlas" in 1979, Massachusetts lost 40 acres per day to development between 1985 and 1989. More recently, that number has inched closer to 78 acres per day. In fact, residential and commercial development displaced around 40,000 acres of farmland and forest - prime bird habitat for many species.

"Such large-scale changes in the landscape are nothing new," said Mass Audubon on its Breeding Birds Atlas Web site at www.massaudubon. org/birdatlas/. "In Thoreau's day, Massachusetts had been largely cleared of forest and consisted mainly of agricultural fields and pastures. Today, the forests have returned and farmland is rapidly dwindling. Such changes in land use, and now in climatic conditions, will continue to alter the natural environment.

"These changes have profound effects on the populations of native plants and animals, effects that are especially conspicuous in the case of birds."

Information must first be gathered, however. To do this, Mass Audubon divided the state up into 970 10-square-mile plots - there are 19 on Nantucket, Tuckernuck and Muskeget islands - and each is surveyed for 20 hours each year for three years by a primary observer. This person can enlist the help of secondary observers in the collection of breeding bird data and when finished with his or her primary duties, can also serve as a secondary observer.

Kennedy's area is called Siasconset Four and includes all the land from the eastern side of Polpis Harbor north, northeast and from the north side of Sesachacha up to Wauwinet. He and the other observers can count breeding birds during certain times of the year called safe dates, a time period when the observed breeding bird species is known to nest and produce young.

"So if I see a whippoorwill from May 25 to July 15, this could be a breeding bird on Nantucket," Kennedy said.

Once spotted, observers log their sightings based on a series of codes, ranging from seeing or hearing possible breeding birds in suitable breeding habitat to seeing eggs and young in nests.

"Throughout the state the deal is somebody is going to be spending 20 hours in these sections looking for

breeding birds," said Kennedy. I