Washington Department of Fish and Wildlife (WDFW) biologists will begin testing at least 2,500 wild birds in July as part of a nationwide avian influenza surveillance effort.
Sampling by WDFW will focus on several species of migratory shorebirds and waterfowl most likely to have interacted with Asian migratory birds in the Arctic this summer. Initial testing will take place on northern Puget Sound and coastal estuaries where those species congregate, although birds in other areas of the state also will be sampled.
“This sampling effort is geared to provide early-detection of the highly pathogenic form of H5N1 avian influenza virus, should it be present in wild birds arriving in Washington,” said Don Kraege, waterfowl section manager for WDFW.
The first priority will be testing wild birds that are found dead, Kraege said, noting that WDFW is cooperating with other state and local agencies to develop a network for collection and testing of dead birds reported in Washington.
Although wild birds naturally harbor various strains of avian influenza-usually without being seriously affected by the virus-one particular sub-strain known as Highly Pathogenic H5N1 has raised concern because some 200 people in Asia and Europe have contracted the virus after close contact with domestic poultry. The “highly pathogenic” designation refers to the virus’ mortality rates on domestic poultry, not its effect on people.
Over the past year, WDFW has incidentally tested approximately 100 wild birds for avian influenza, either because the birds were found dead or because they were encountered in conjunction with other wildlife management activities. Thus far, no wild birds anywhere in North America have tested positive for the highly pathogenic Asian H5N1 virus.
The new WDFW testing program is part of a broad state and federal avian influenza surveillance plan in Washington and elsewhere across the country. Besides WDFW’s testing, the plan provides for additional sampling of 1,500 live and hunter-harvested birds and 1,000 fecal samples in Washington by the U.S. Department of Agriculture (USDA), and sampling at gamebird farms and wildlife rehabilitators by the state Department of Agriculture.
The sampling effort is funded under a $1.06 million USDA grant to states along the Pacific Flyway, a bird migration route through the western United States. WDFW received $140,000 from that grant to conduct its portion of the testing program. In addition, the U.S. Fish and Wildlife Service is providing $300,000 for avian influenza sampling in the state.
Live bird tests will involve temporarily capturing birds in nets and collecting respiratory and fecal samples for laboratory testing.
Besides testing live birds, WDFW also will test 800 hunter-harvested waterfowl at check stations this fall. In addition, WDFW will collect 500 samples of bird droppings to check them for the virus.
WDFW’s live waterfowl testing will focus primarily on pintails and mallards, with additional testing of wigeon, green-winged teal, shovelers and sea ducks as the opportunity arises in conjunction with other sampling activities.
Shorebird testing will focus on western sandpipers and dunlin, with opportunistic testing of red knots and ruddy turnstones.
While the highly pathogenic form of the Asian H5N1 virus has not been found among wild birds in North America, some scientists anticipate that Asian birds migrating to the Arctic this summer could transmit the virus to North American wild birds. A similar wild-bird surveillance effort is already under way in Alaska.
Biologists estimate approximately one million geese, 12 million ducks and 150,000 swans returning from the Arctic pass through the Pacific Flyway each year, beginning in August. In addition, hundreds of thousands of autumn-migrant shorebirds arrive in the state between July and October.