Development takes toll on U.S. bird populations

While populations of some birds have plummeted, bald eagles are among species whose numbers have grown.

Several major bird populations have plummeted over the past four decades as development transformed the nation's landscape, but conservation efforts have helped to stave off potential extinctions of others, according to a comprehensive survey released by the Interior Department and outside experts.

“The State of the Birds” report, a sweeping analysis of data compiled through scientific and citizen surveys over the past 40 years, shows some species have made significant gains even as others have suffered. Hunted waterfowl and iconic species such as the bald eagle have expanded in number, the report found, as birds along the nation's coasts and in its arid areas and grasslands have declined sharply.

“Just as they were when Rachel Carson published 'Silent Spring' nearly 50 years ago, birds today are a bellwether of the health of land, water and ecosystems,” Interior Secretary Ken Salazar said in a statement. “From shorebirds in New England to warblers in Michigan to songbirds in Hawaii, we are seeing disturbing downward population trends that should set off environmental alarm bells.”

The fact that concerted conservation efforts have saved birds such as the peregrine falcon and allowed various wetland birds to flourish, scientists said, shows that other species can reverse their declines with sufficient support from federal agencies and private groups.

“When we try, we can do it,” said John Fitzpatrick, executive director of the Cornell Laboratory of Ornithology. “There are now populations and habitats across the country begging for us to do it.”

The species in decline are being affected by climate change, habitat destruction, invasive species and disease, among other factors, the report found. More pedestrian threats, such as collisions with buildings and attacks by feral cats, have diminished birds' numbers in some urban and suburban areas.

Hawaii, more than any other place in the country, highlights the challenge native American birds face. Seventy-one bird species have disappeared since humans populated the Hawaiian islands in A.D. 300, and another 10 have not been spotted in years. At the moment, more than a third of the bird species listed under the Endangered Species Act are in Hawaii, but state and federal agencies spent only $30.6 million on endangered birds there between 1996 and 2004, compared with more than $722 million on the mainland.

“In Hawaii we've got lots of imminent extinctions, but not enough resources being spent on them,” said George Wallace, vice president of the American Bird Conservancy.

Bird advocates have enjoyed more success in raising money to protect North American waterfowl, which have a powerful political constituency among sport hunters.

In some cases, however, public and private protections for key bird species are in jeopardy. The Conservation Reserve Program provides federal dollars to farmers in order to preserve vital habitat on which species such as the lesser prairie chicken depend, but contracts encompassing 3.9 million acres are set to expire by the end of September.

Michael J. Bean, who directs the wildlife program for the Environmental Defense Fund, an advocacy group, said losing these grasslands “could be the tipping point that makes an endangered species designation for the lesser prairie chicken unavoidable.”

Placing the bird on the endangered species list, Bean added, could make it more difficult for entrepreneurs to build wind projects in the southern Plains. As a whole, birds that breed only in grasslands have declined by 40 percent over the past four decades.

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