A little bird that spends its winters on the Georgia coast is one of the animals most threatened from sea level rise, according to researchers.
Saltmarsh sparrows are small, streaky brown-striped songbirds with a voice like a squeaky whisper.
They split their time the same way some humans do: They spend their winters on the Georgia coast, then head back up north in the spring. That's where the birds breed, in coastal marshes from Virginia up into Canada.
“We’ve documented real site faithfulness to areas on the Georgia coast,” said Tim Keyes, a wildlife biologist with the Georgia Department of Natural Resources. He said the sparrows come back to the same spots in Georgia year after year. “Clearly it’s a really important wintering site for them.”
Keyes said the problems for saltmarsh sparrows seem to be in the places where they breed in the Northeast. Those marshes have been shrinking because of development, and sea level rise is making things worse. The sparrows' nests are getting flooded.
“They appear to be declining just at a ridiculous -- something like 9 percent annual decline,” he said. “They seem to be in more trouble than any other bird species that I work with.”
A study in the Northeast last year found that saltmarsh sparrows could go extinct in the next 50 years.
“The saltmarsh sparrow is probably the species most affected by sea level rise and may be the first lost because of it,” Keyes said. “It’s a beautiful bird, really interesting bird, but it’s unbelievably vulnerable.”
Keyes is working on a program with Georgia DNR and the U.S. Fish and Wildlife Service to put tiny radio transmitters on the birds, so that scientists can learn more about where they live in Georgia, and where they go when they leave the state. Towers up and down the coast will pick up the birds’ signals as they migrate.
Keyes said even with well-studied species, researchers don’t necessarily know much about specific populations of birds, and if they may be declining in some parts of their range. Radio telemetry and other tools, like satellite tags, have given scientists a chance to learn a lot more about birds’ migration patterns. As the technology advances, the tags can get smaller and smaller, meaning they can be attached to increasingly diminutive birds – like saltmarsh sparrows.
“There’s oftentimes very little known, though the technology is advancing rapidly,” he said. “It’s just astounding what we’re learning.”