In search of food, strange birds arrive on ACK
BY PETER B. BRACE INDEPENDENT WRITER
Migratory birds that cannot find enough seeds and berries in their traditional Canadian wintering grounds are blitzing Nantucket bird feeders in search of food.

PHOTO BY BRUCE DEGRAAF

This particular fall/winter season is turning into a bountiful birder's paradise in what island bird expert Edie Ray calls an irruptive year. Species that do not normally winter in these parts have "erupted" much farther south of their normal wintering grounds, searching for food that is believed to be in short supply up north.

Seed and berry-eating birds that are on Nantucket because of the failure of the northern seed crop include nuthatches, pine siskins, crossbills, pine grosbeaks, evening grosbecks, bohemian waxwings and common redpolls.

"It's not just Massachusetts, things are showing up in Connecticut that are not usually there in a regular winter," said Ray, who added that there are also many more white-breasted nuthatches than normal on island this year. "It's going to be an interesting winter at the bird feeders."

Simon Perkins, Staff Ornithologist at the Massachusetts Audubon Society in Lincoln, Mass. said such irruptive species have been spotted as far south as New Jersey.

The red-breasted nuthatch, as seen here at a feeder on Salros Road, left, and the red crossbill, far left. ROB BENCHLEY/The Independent

Birds such as the Northern shrike, which feeds on small mammals and small birds, are also expanding their winter range in search of food. Other birds not normally found in the region this time of year have been inexplicably spotted around Nantucket - including a white-winged dove, a black-chinned hummingbird, a snow goose and a cattle egret. And, said Perkins, snowy owls are now present at Logan Airport in Boston.

But Perkins disputes Ray's belief that there is an explosion of nuthatches on Nantucket as part of this irruptive year.

"It is a common winter resident on Nantucket," he said. "In the big picture, this is not any part of a larger irruption for nuthatches. My guess is the Christmas Bird Count [on Dec. 29] is not going to turn up an inordinate number of them.

"Typically these birds are not found too far south of the Canadian border, but I have heard through the grapevine that we are getting these birds at least as far south as New Jersey."

As to why seed and berry crops are so diminished that birds need to fly south in search of food, neither Ray nor Perkins could offer a definitive answer, and both dodged the easy scapegoat of global warming, which both believe is still too much of a moving target to be a direct link.

"It's a more complex question and no one has a handle on it," said Perkins. "I have yet to hear a really concise explanation as to what can cause failure across such a large area and a loss across a wide variety of food plants."

Gold and purple finches, several species of sparrows, red-breasted and white-breasted nuthatches, chickadees, cardinals, blue jays and Carolina wrens are just a sampling of birds that are usually seen on

island during the fall and winter. I