CORNELL (US)—As oil washes ashore along the Gulf Coast, birders are asked to keep an eye on nests—not just near water, but hundreds of miles inland as well.

“Wildlife biologists are monitoring species such as pelicans and plovers in the immediate path of the oil,” says Laura Burkholder, an extension specialist at the Cornell University Lab of Ornithology.

“But we need bird watchers across the country to help us find out if birds that pass through or winter in the Gulf region carry contamination with them, possibly creating an ‘oil shadow’ of declines in bird reproduction hundreds of miles from the coast.”

Cornell’s NestWatch project enlists the public’s help to find and visit a nest for a few minutes twice a week, and record data including how many eggs it contains, how many chicks hatch, and how many leave the nest.

“Many birds that nest in backyards all across North America, such as red-winged blackbirds and tree swallows, spend part of the year along the Gulf of Mexico, where they could be affected by the oil spill,” Burkholder says.

“Toxins often have profound effects on reproduction, and it’s possible that toxins encountered in one environment can affect the birds in another environment, after they arrive on their breeding grounds.”

When participants across large regions contribute information, Burkholder says, scientists can assess changes in nesting success in relation to such environmental factors as habitat loss, climate change, and pollution.

Burkholder says it’s especially critical to capture data on nesting birds to reveal the health of birds before they encounter the oil spill—as well as in the years ahead, to detect possible long-term effects.

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