Philadelphia Inquirer, June 15, 2007

THE DISAPPEARING BIRDS

Audubon report says even common species are having trouble

[Rachel's introduction: Here is more evidence that we are shredding the biosphere one small decision at a time, diminishing the world we will leave to our children. This occurs because of what we produce and how we produce it, both of which are the result of choices.]

By Sandy Bauers, Inquirer Staff Writer

Get National Audubon Society's full report

When he was a boy in the '60s, Schuylkill Haven nature writer Scott Weidensaul considered the eastern meadowlark a sound track of summer. Ask any New Jersey farmers, and they will wistfully recall the whistles of the bobwhite.

Yesterday, the National Audubon Society quantified what birders and other outdoors people have known for years: Many of America's most common bird populations have plummeted over the last 40 years, the bobwhite, the biggest loser, by 82 percent.

The message, Weidensaul said, is that "no species is safe" from sweeping landscape changes such as development, loss of wetlands, and pollution from industry.

"If even the commonest, most widespread birds are having trouble thriving, it's a pretty clear warning that we need to take action," Weidensaul said during a teleconference with reporters.

The study's author, Greg Butcher, the Audubon Society's national bird conservation director, was quick to point out that while none of the birds was in danger of becoming extinct, the declines indicated serious problems that should -- and can -- be addressed.

Butcher drew up a top-20 list that includes the northern pintail, several sparrows, the whip-poor-will, the eastern meadowlark, and the ruffed grouse, Pennsylvania's state bird, all of which he said had declined more than 50 percent.

"These are not rare or exotic birds we're talking about," said Carol Browner, the Audubon Society's chair and the head of the Environmental Protection Agency in the Clinton administration. "These are birds that visit our feeders and congregate at nearby lakes and seashores, and yet they are disappearing day by day."

Nate Rice, ornithology collection manager at Philadelphia's Academy of Natural Sciences, said he was not surprised at the analysis, based on four decades of citizen counts, a bulwark of bird science.

"I can totally believe it," Rice said. "If this isn't the biggest red flag one can raise, I don't know what is."

For years, ornithologists have been particularly concerned about migrants such as warblers that wing up from the tropics every year. "It just goes to show you it's no longer one group," Rice said. "It's becoming systemic for all birds."

For the study, the Audubon Society came up with a list of several hundred "common" birds, defining them as those with populations numbering at least 500,000 in North America, with ranges of a million square miles or more. The statistical analysis looked at decades worth of two national counts -- the Audubon Christmas bird counts and the U.S. Geological Survey's Breeding Bird Survey.

Butcher said that while the report had not been peer-reviewed, the techniques used "have been extensively peer-reviewed."

The main reason for the decline, he said, is habitat loss -- reduction in grasslands because of intensive farming, a loss of forests due to suburban sprawl, and loss of wetlands because of industrialization.

Echoing other studies, however, he said climate change exacerbated habitat loss.

Species that must shift their range north because of rising temperatures might be unable to find habitat bridges or pathways to get there, said Eric Stiles, vice president for conservation and stewardship at New Jersey Audubon, which is independent of the national group.

"Because we've sliced and diced the landscape," he said, "they're stuck on these islands. It's kind of a Berlin Wall for ecology."

In Pennsylvania, where the ruffed-grouse population has declined 22 percent, "a big part of the problem is that they're sharing the forest with a lot of very hungry white-tailed deer," Weidensaul said.

"The understory that the birds need for cover from predators and the insects they depend on just aren't there anymore," he said.

Likewise for the wood thrush, said Tim Schaeffer, executive director of the National Audubon Society's Pennsylvania chapter. Almost 10 percent of the world's wood thrushes nest here, he said.

"These are are common birds for which Pennsylvania has a worldwide responsibility for maintaining their habitat."

In New Jersey, bobwhites used to proliferate as far north as Hunterdon County but now remain in only a few spots in Cape May and Ocean Counties. "They're extremely uncommon," said New Jersey Audubon's director of conservation, Troy Ettel.

Common terns, whose numbers are down 70 percent nationally, have been booted from their nesting habitat on barrier-island beaches by houses or eaten by cats and other predators that come with the people who live there.

A lot is happening in both states to help the birds.

The Pennsylvania Audubon chapter, for instance, is working with groups like the Willistown Conservation Trust in Chester County to delay mowing their fields until after July 15, when grass-nesters such as the eastern meadowlark have fledged their young.

The Friends of the Wissahickon is promoting an Audubon backyard program emphasizing native plants that will benefit native birds.

New Jersey wildlife officials have been mapping the remaining bobwhite habitat to devise a conservation plan.

Birding organizations have long relied on common citizens for both science and action. Audubon is urging people to to replant their yards with native species, support reforms to farming and logging practices, and fight global warming through their lifestyles and support of legislation.

The new report, Weidensaul said, "is an early warning. We have the time to turn things around. We have the tools to turn things around. What we really need is the will and the determination to do it."

Listen to vocalizations of the top 20 declining bird species via ht tp://go.philly.com/earth

Contact staff writer Sandy Bauers at 215-854-5147 or sbauers@phillynews.com.

How to Create a Backyard habitat for Birds.