The search for the first wild bird carrying a deadly flu virus to North America is under way on a lonely stretch of coastal salt marsh on the outskirts of Alaska’s largest city.
Biologists are ankle-deep in mud and yellowed marsh grass, trying to net and test two types of shorebirds. Both are known to visit regions where flocks have caught the dangerous H5N1 virus that has spread across Asia and even into Europe and Africa.
“Birds up here are going to be interacting with birds that are going to be moving back in the United States. This is kind of Grand Central Station,” said Paul Slota of the U.S. Geological Survey, who will be overseeing the testing of samples back at the USGS wildlife lab in Madison, Wis.
The focus now is on long-billed dowitchers and pectoral sandpipers, just two of the 28 bird species that come to the great avian mixing zone that is Alaska. If bird flu can be carried long-distance by wild birds, experts hope to see it first here, before the fall migration through other states.
Of course no one knows if the H5N1 flu will arrive on the wings of a migratory bird. Or if it will reach this continent this year. But if it does, federal wildlife officials want to stop it from spreading through many bird species and threatening domestic poultry.
Bird flu has killed or led to the slaughter of millions of chickens and ducks in Asia. It has infected more than 200 people who had very close contact with poultry. Of the known human cases, about half of the victims have died.
The big fear is that this virus will mutate into a virulent form that can easily infect people and spread among them.
But for now the mission at hand is swabbing the back sides of dowitchers and sandpipers to get fecal samples that will be tested for bird flu. The project is so massive, Alaska biologists have faced a swab shortage. Nationwide, the goal is to sample 75,000 to 100,000 wild birds.
The long-billed dowitcher is a 10-inch gray shorebird with long legs. It breeds in high-latitude coastal wetlands in Alaska, Canada and the Russian Far East.
Those that breed in Russia range near H5N1 outbreak areas in Asia and mix with birds that could be infected. Then they pass through Alaska in spring and fall.
Half of the world’s pectoral sandpipers breed in Alaska or Canada, the other half in Russia. Small numbers of Siberian birds winter in Southeast Asia, Australia and New Zealand and have the potential to pick up the virus along the way.
Each May, some pectoral sandpipers make a stop on the Anchorage salt marsh, a beach of mud, grass and brackish ponds that stretches a thousand feet to Cook Inlet. The view is magnificent — across the water is Mount Susitna, known locally as Sleeping Lady because of its resemblance woman reclining on her side — but the standing water, mud and rotting vegetation give off a slightly sweet odor of decay.
To a wading bird traveling from South America, it’s a buffet line. The shorebirds feed on seeds, emerging beetles and spiders. With their sensitive bills, they probe the top half-inch of the mud for fly larvae, said USGS biologist Bob Gill.
“They can feel a clam move from a few centimeters away,” he said.
Bird tracks blanket the bottom of the shallow ponds. Biologist Dan Ruthrauff ducks down behind a weathered log, waiting for his prey to fly into an 8-foot-tall, 45-foot-wide fine-mesh mist net. Over the course of the day, the net captures more than 20 sandpipers in several varieties.
Ruthrauff quickly extracts the birds, puts them into cloth bags and takes them to a table where Gill and other biologists use digital calipers to measure beaks, wings and legs.
Handling one, Gill says the bird may have flown all the way from Chile. “It probably started a month ago and could go as far as the Taimyr Peninsula” in northernmost Siberia.
He banded its leg, took a blood and feather sample, and holding the bird upside down, swabbed for a fecal sample. The H5N1 virus replicates in a bird’s intestines.
Gill heads up the survey for shorebirds. Other Alaska biologists at more than 40 remote sites will focus on waterfowl, seabirds and perching birds. Several thousand hunter-killed birds also will be checked with the help of local subsistence hunters.
Sometime this week, when there are 50 to 100 samples are in hand, they will be sent to the USGS National Wildlife Health Center lab in Madison, Wis. There, under Slota’s supervision, the testing begins.