for National Geographic News
After more than six years of research, scientists have named the 500 most important bird areas in the United States. With a map already finished and a book on its way, the researchers hope their list of hotspots will help focus conservation projects where birds need them most.
"There are birds everywhere," said Gavin Shire, director of communications technology for the American Bird Conservancy in The Plains, Virginia. "Recognizing these places is the first step toward conservation and protection."
Times are tough for birds all over the world, Shire says, for a variety of reasons. Global climate change, logging, and development have chopped up critical habitats, making it harder for birds to get enough to eat or find enough space to breed. Many places that migratory birds habitually stop are rapidly disappearing. Meanwhile, domestic cats kill millions of birds every year, while others die from collisions with communication towers, toxic pesticides, or disease epidemics like the West Nile virus.
Bird deaths often warn of other environmental problems, too, Shire said. "Birds are a good indicator of the general ecological health of the planet."
Birds Have Needs Too
More than 3,500 Important Bird Areas have been designated around the world, with ongoing projects in Europe, the Middle East, Africa, and Ecuador, among other places. The United States effort began in 1995, when scientists at the American Bird Conservancy started scanning scientific journals and interviewing managers of parks and wildlife refuges. In total, more than 500 biologists and conservationists gave their input.
There are four ways a site can earn IBA status, and some sites fit into more than one category. More than 200 of the top 500 U.S. designations went to areas where significant populations of endangered and threatened species live, such as piping plovers and Kirtland's warblers.
Nearly half of the top 500 IBAs are prime habitats for species on the Partners in Flight Watch List, which identifies birds that scientists think will be next in line for the endangered species list, if nothing is done to protect them. Cerulean warblers and Henslow's sparrows are two examples.
Birds with small home ranges also raise red flags for the IBA-designators. "The smaller the range of the species," Shire said, "the more vulnerable it is."
Tricolored blackbirds, for example, live only in wetlands of California, with limited ranges in Oregon and Baja California. If those habitats disappear, the species will quickly follow.
Finally, the researchers look for places where migratory birds usually stop on their long journeys between seasons, such as the Delaware Bay, where hundreds of thousands of red knots and other shorebirds stop every spring to spawn and gorge themselves on horseshoe crab eggs before continuing their flights up north.
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