Over the 10 weeks crude has been gushing into the Gulf, more than 2,000 pelicans, cormorants, gannets and water birds have been plucked from gooey slicks and blackened shorelines — about 60 percent of them already dead.
Those numbers could soar, starting as early as this weekend. In the coming months, birds begin migrating from as far north as the Arctic into the coastal marshes, estuaries and beaches. For many, the seasonal rest and refueling stop could wind up a deathtrap.
Federal wildlife managers and scientists are hatching plans to create new, unfouled havens by flooding idle farm fields and other measures. But they acknowledge there is only so much they can do to distract birds from danger zones in the 120 miles of coastline from Louisiana to Florida already contaminated by oil.
“We won’t be able to dramatically affect migration in any way, shape or form,” said Paul Schmidt, assistant director for migratory birds for the U.S. Fish and Wildlife Service. “The birds are still going to do what they do in the natural cycle.”
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Wildlife managers, he said, expect the sort of massive mortality figures normally associated with disease outbreaks or natural disasters like wildfires or hurricanes.
Ornithologist Greg Butcher, director of bird conservation for the National Audubon Society, believes the official avian victim tally already falls far short of what has really happened and will only get worse. In past spills, experts have estimated that less than one in 10 exposed birds are ever recovered, dead or alive.
“The problem is so many of these birds die unseen,” he said.
Starting as early as this weekend with the arrival of shorebirds like sandpipers and greater yellowlegs from a month-long breeding season in the Arctic, the Gulf Coast becomes what Audubon President Frank Gill likened to a Grand Central Station for migratory birds.
Some 300 species — from blue-winged teal to red-headed ducks and white pelicans — will pass through the Gulf over the next six months, most in pathways birders call the Mississippi Flyway. Many are moving from breeding grounds in Alaska, Canada and the northwestern United States to feeding grounds in Central and South American and the Caribbean.
“It’s really a billion birds,” said Butcher. The vast majority may be songbirds, grassland or forest species unlikely to be affected but millions will instinctually hone in on shorelines, marshes and sea grass beds tainted by oil or threatened by it.
The Fish and Wildlife Service is working with the other agencies as well as conservation groups like Ducks Unlimited and the National Fish and Wildlife Foundation, to improve or create bird-friendly habitat. They plan to burn or remove exotic plants choking some national wildlife, expand programs that flood rice or corn fields north of the coast and take other steps.
“The key is to do it inland in freshwater areas where they are not tempted to go to the coast,” said Butcher.
While those efforts won’t make sweeping differences they could help in local pockets, Schmidt said: “Hopefully, we can get them to stay in clean areas a little longer and reduce their exposure.”
Wildlife managers also may consider scaring birds away from badly oiled areas but those efforts — usually using fireworks, horns or plastic streamers — typically only work for the short-term, he said.
Images of pelicans and other birds, struggling under dripping toxic shrouds, have provided some of the most disturbing images from the ongoing environmental disaster. But birds don’t have to be coated for oil to do damage. Simply standing in it or getting it on their feathers can affect their ability to stay dry and warm and they can ingest it as they preen in attempts to clean themselves.
Rehabilitation facilities across the Gulf are bracing for more work. As of Thursday, rescue teams had recovered 881 birds alive from oiled areas — 695 in Louisiana, 127 in Florida, 50 in Mississippi and nine in Alabama. More than 330 have since been released.
More than 1,200 have been collected dead — 470 in Louisiana, 437 in Florida, 238 in Alabama and 109 in Mississippi.
Biologists with the Florida Fish and Wildlife Conservation Commission said Friday that 35 greater shearwaters, gull-like birds found dead last week from Delray Beach to Cocoa Beach, were not victims of the spill but of hunger after long crossings from breeding grounds in South Africa.
Michael Ziccardi, a University of California-Davis professor who has spent nearly two months in the Gulf, defended the time and expense poured into cleaning oiled waterfowl -- an effort that routinely draws questions from skeptics and some scientists.
He said studies finding low rates of survival date back a decade or more and survival rates for birds brought in alive now can run from 50 to 75 percent. But Ziccardi, who directs the Oiled Wildlife Care Network based at UC-Davis and has studied the issue extensively, said there are unanswered questions about the breeding prospects and long-term survival of some species.
Cleaning and rehabbing a bird can take several weeks and run thousands of dollars but Ziccardi said it was worth it — particularly since BP, not the public, was footing the bill.
“Personally, I don’t see it as waste of resources in that those funds are coming from the responsible party,” he said.