Bird numbers dwindling

"Things we all think of as familiar backyard birds ... they appear in books and children's stories and suddenly some of them are way less familiar than they should be," said John Fitzpatrick, director of the Cornell ornithology lab, who was not part of the study.

Audubon Board Chairman Carol Browner, former head of the U.S. Environmental Protection Agency, called the declines "a warning signal."

"We are concerned. Is it an emergency? No, but concerns can quickly become an emergency," she said.

While these common birds are in decline, others are taking their place or even elbowing them aside. The wild turkey, once in deep trouble, is growing at a rate of 14 percent a year. The double-crested cormorant, pushed nearly to extinction by DDT, is growing at a rate of 8 percent a year and populations of the pesky Canada goose increase by 7 percent yearly.

Many of the birds that are disappearing are specialists, while the thriving ones are generalists that do well in urban sprawl and all kinds of environments, Butcher said. In a way it's the Wal-Mart-ization of America's skies, he said.

"The robins, the Carolina wrens, the blue jays, the crows, those kinds of birds, are doing just fine, thank you," Butcher said. "They really get along in suburban habitats, most of them even like city parks, so they are not as susceptible to the human changes in environment."

But nothing matches the take-over ability of one invading bird.

"Right now the Eurasian collared-dove is conquering America," Butcher said. A dove-like bird that first entered Florida in the 1980s, it now is the most prevalent bird in the Sunshine State and is in more than 30 states.

"Soon you'll be seeing Eurasian collared-doves in any city in the world," he said.