The worst oil spill in U.S. history is several states away. But next spring when Maine birds that spend the winter in the Gulf of Mexico return here, local birders may feel more closely linked to the BP oil disaster.

“We will be monitoring if those populations undergo a decline because there is not enough food. We don’t expect any birds to go extinct. The piping plover is endangered, but fortunately the entire population does not winter in the Gulf,” said Greg Butcher, National Audubon’s director of bird conservation.

Some ornithologists in Maine are worried the oil spill caused by an explosion on April 20 will hurt birds that have nested here for decades.

And Jeff Wells, a senior scientist for the Boreal Songbird Initiative in Maine, said the effects on Maine birds may not be realized for several years.

“We know from the Valdez oil spill and other oil spills, we can only get a percentage of the oil. Even though it’s not obvious, you dig down into the sand or marshes, the oil is sitting there. Any birds that are probing into that stuff, of course they are going to pick it up,” said Wells, the former director for bird conservation at National Audubon.

Wells is concerned about shore bird species with long bills that dig for food, and also diving ducks, species that would winter in the Gulf of Mexico.

And while those birds may survive, certain species may suffer liver damage or cancer from the oil, which could lead to dips in the populations later, Wells said.

“Depending on conditions, that could cause lower breeding success,” Wells said. “It’s a bit hard to predict what will happen. It’s really hard to measure.”

The oil that remains could affect the food chain, of which the migrating birds are a part. Aquatic insects may die off, hurting fish that feed on the insects and that in turn could harm the birds that feed on those fish, Wells said.

National Audubon has created two new staff positions to help volunteers monitor these populations, Butcher said.

“We are concerned the oil has killed off smaller organisms, zooplankton and phytoplankton. We’re concerned there is a lack of food supply for shrimp and fish,” Butcher said.

But the best-funded surveys may come from the federal government, Butcher said, and the findings of those may not be accessible any time soon.

“One concern is that the people conducting those (federal) studies are reporting to the courts in the settlement between the United States and BP,” said Butcher in Washington, D.C.

In Maine, Wells is hoping birders next spring take special note of the numbers of returning shore birds and migrating ducks, like the short-billed dowitcher and green-winged teal.

And he hopes if the numbers are down, birders here reflect on the historic incident and realize how interconnected we are through nature.

“It’s a great example of how what can happen in one area can affect the good work done by another, protected area,” Wells said. “It’s safe to say some portion of the populations of some of these species will be affected. Some will sicken and die. The question we don’t know is, will it be enough to cause a drop in the population that would be measurable?”

Staff Writer Deirdre Fleming can be contacted at 791-6452 or at:

dfleming@pressherald.com