From: Theday.com
By Judy Benson
Published on 6/5/2009
Stonington - Professor Chris Elphick leaned down to part some emerald tufts of salt meadow cord grass, exposing a rounded mat of gray, dried blades beneath, like a tiny upturned basket.
In a secret pocket such as this, he explained, a little brown, white and yellow bird with a whisper-soft song, some very unique behaviors and a most precarious future builds its nest.
”The first 20 nests are hard to find,” Elphick, a professor of ecology and evolutionary biology at the University of Connecticut, said. “Then you start learning some tricks. You get an eye for how the birds behave when they're near their nests.”
He pointed to a wisp flying low over the marsh, at the Barn Island Wildlife Management Area. It quickly disappeared into a patch of marsh elder. With just that glimpse, Elphick knew he had spotted a salt marsh sharp-tailed sparrow, an unassuming and previously little-known species he's devoted much of the last seven years to studying. As concerns about climate change and associated rising seas have grown, Elphick's work has taken on an increasing practical urgency, because the research has shown these birds are one of the most vulnerable species in the Northeast.
”He's done groundbreaking work,” said Patrick Comins, director of bird conservation for Audubon Connecticut.
Because up to one-third of the entire world population of this sparrow makes the Connecticut shoreline its home for mating, nesting and fledgling in spring and summer, Elphick's research has been done entirely at 45 salt marshes on the state's shoreline. Of those, he said, the three most important sites are Great Island in Old Lyme, Hammonasset State Park in Madison and the East River marsh in Guilford. After that comes Barn Island. Spring high tides over the last few weeks are an especially critical time.
”There are probably 200 to 300 of them here,” Elphick said, toting spotting scope and binoculars as he walked one of the paths between the marshes at Barn Island. “At the other three sites, there are probably a couple of thousand. This is a bird Connecticut has a lot of responsibility for, in a global sense.”
Victim of its nesting habits
No other bird species, Elphick contends, attunes mating and nesting around the spring high tides like this sparrow. Because the success of its offspring depends on getting the timing just right, any change in sea levels, no matter how slight, can make all the difference. That means that as climate change causes seas to swell, more water will flood the salt marshes where the birds nest than they have adapted to withstand.
”This species is doomed, even with modest sea-level rise projections, without drastic action,” Comins said. “I believe this species is the one most likely to go extinct in Connecticut in our lifetime” if nothing is done to save it.
”Almost every talk I give these days I mention the impact of climate change on the salt marsh sharp-tailed sparrow.”
Not recognized as a distinct species until 1995 - before that it was erroneously lumped with the Nelson's sharp-tailed sparrow - the salt marsh sharp-tailed sparrow now commands the interest not only of Elphick and his graduate assistants, but of policymakers and wildlife experts concerned about the effects of climate change. Elphick's expertise has been called on by the state Department of Environmental Protection panel examining how wildlife is being affected by climate change and what steps the state should take to protect critical habitats.
”They live in a narrow band along the coast. For a bird that's a very small geographic range,” Elphick said. “They're so vulnerable to sea-level rise, because the difference between a good spot for a nest and a bad spot can be just a few centimeters.”
In other words, a sparrow that nests under a tuft of grass growing at a slightly higher elevation than another will see its eggs survive spring flooding, while a nest in the other may not.
Salt marsh sharp-tailed sparrows, Elphick said, build their nests high enough to be out of the water at low and mid-tide, but low enough to be concealed from predators. For one phase of his research, his team placed heat sensors on nests. By monitoring temperature changes, they were able to conclude that eggs in a nest can withstand being under water at high tide for 60 to 90 minutes. The mother bird must return by then to rewarm the eggs, or they will drown.
