The U.S. is home to an amazing 800 species of birds, but nearly a third of those species are endangered, threatened or in decline. That’s the news from “The U.S. State of the Birds, 2009”—the most comprehensive study ever of the health of North American birds, released today.

The data are a warning sign about the shape of the environment, according to the report. Birds are literally the "canary in the coal mine," Secretary of the Interior Ken Salazar said at a press conference today. "This report is a clarion call to action," said Salazar at a press conference, noting that some of the major factors threatening birds include growing human populations, climate change and water quality.

The report (pdf) synthesizes more than 40 years of data from three long-running bird censuses conducted by thousands of citizen scientists and professional biologists through programs such as the National Audubon Society's annual Christmas Bird Count.

Among the report's highlights:

•    U.S. grassland bird species have declined 40 percent
•    Birds in arid lands have declined 30 percent
•    39 percent of U.S. birds restricted to ocean habitats are declining
•    Some coastal shorebirds are doing well, but many face habitat losses and dwindling food supplies
•    and birds in Hawaii face a conservation crisis, with many species on the edge of extinction

But not all of the news is bad. "The report also says there are ways we can address these problems in a systemic way," said Salazar. "Conservation can really work. There are places were many bird species are doing better today than we were 10-15 years ago. Those success efforts should lead us to what we should be doing in the future."

"We need to protect habitat and aggressively attack climate change with renewable energy," said John Flicker, president of the National Audubon Society. The report also lists several actions that individuals can take to help birds, such as growing native vegetation, avoiding pesticides, keeping cats indoors, feeding birds in your neighborhood, and taking steps to prevent birds from dying when they strike building windows.

Among the success stories, according to John Fitzpatrick, director of the Cornell Lab of Ornithology, one of the partner organizations in the report: Efforts to save the whooping crane, bald eagle, peregrine falcon, and many species of waterfowl. "This report emphasizes that with careful monitoring and bringing together public funds and commitment and private funds and commitment, we can see species come back," Fitzpatrick said.

And those efforts don’t always require tons of scientists. The information that went into this report was gathered by ordinary people around the country—"tens of thousands of people, perhaps millions, who have found that science is fun," said Fitzpatrick. The information gathered by birdwatchers and citizens in their own back yards has helped to create "spectacularly massive databases" which Fitzpatrick says can now be used to find trends in bird populations. "We should engage all Americans in this process," he said.

In short, he said, "citizen science rocks."

Image: Bald eagle (Haliaeetus leucocephalus) in front of the U.S. flag. / John De Boer / StockXchng