Migrating birds find a slim choice of stops
ESSEX COUNTY, MASS.
Few sounds evoke a stronger sense of fall than the migratory call of Canada geese as they fly in well-formed skeins overhead.
As these and other birds wend their way south, new research suggests that the areas they use to layover en route to wintering grounds are as important as the destinations themselves. This insight has alerted researchers to the need to preserve and protect these crucial sites.
"We have discovered that migratory stop-overs are as important as winter and summer grounds," explains Sally Conyne, director of Citizen Science, a program at the National Audubon Society linking 50 million bird watchers nationwide. "These areas are critically important and can be found across North America and around the world."
Consider the swallow-tailed kite, a raptor whose winter migratory destination was recently discovered using satellite tracking. By attaching beacons to the birds' backs, researchers tracked the kite to a single prairie tree in Brazil, where some 300 were roosting.
Sidney Gauthreaux, professor of biological sciences at Clemson University in Clemson, S.C., finds this situation precarious. "If something happened to that one tree, it could eliminate hundreds of birds in the United States," he says. "We are now starting to realize how vitally important these habitat issues are."
This realization has spawned a shift in the way migratory conservation is being carried out. The mantra is "keeping common birds common," a theme repeated by ornithologists across the country.
"We're moving from an era of regulation and reactive conservation to one of proactive conservation," says Frank Gill, senior vice president for science at the National Audubon Society.
Armed with this new focus, researchers are concentrating on identifying areas of critical habitat to ordinary birds.
"Migrants are very sophisticated about choosing where they stop. But if you provide nice places, birds will come," Dr. Gill says. "They have to refuel, they have to rest for the next leg. They need a motel, and in some ways taking interest in migrants is building motels for them."
Enter Partners In Flight, an organization whose tenet, according to Kenneth Rosenberg, northeast regional director of PIF, is to study and promote the welfare of nongame birds. The notion sounds simple: to preserve habitat before a bird's status becomes acute. But Dr. Rosenberg sees this as a novel and important move away from the push for listing birds as endangered species.
"There is a huge cost to society to play the endangered-species game," Rosenberg says. "That's all we did for 20 to 30 years. Today, we are taking a new direction and looking for common ground."
In particular, Rosenberg has focused attention on ground used by the cerulean warbler, a neotropical bird and a species at risk. The cerulean warbler presents a classic case of challenges faced in protecting migratory species. Wintering on the slopes of the Andes in the heart of coffee and cocoa growing areas, the bird has needs that are inextricably bound to those of the native people.
"These birds are very vulnerable on both ends of their journey," Rosenberg says. "But trying to stop a foreign culture from doing something that is part of their subsistence needs - that is very hard."
Despite habitat preservation challenges, the cerulean warbler and other migratory birds have been aided by the North American Bird Conservation Initiative (NABCI), an organization established through the North American Free Trade Agreement. Pulling together a vast array of birding interests in America, Canada, and Mexico, NABIC's coverage stretches from the Arctic through southern Mexico. And while Brazil and the cerulean warblers' winter grounds are not covered, many other migratory routes are.
"There is a new wave of optimism and an unprecedented degree of cooperation," Rosenberg says of the program.
All of which is good news for the cerulean warbler, the swallow-tailed kite, and hundreds of migratory birds that have long been overshadowed by other birds on the endangered species list.
*For information on cerulean warblers: http://birdsource.cornell.edu/cewap/index.html
(c) Copyright 1999. The Christian Science Publishing Society