Swabs were taken from about 500 wild birds in Whatcom County by officials who want to know how widespread a highly pathogenic bird flu is among the region’s wild birds.
They were among more than 1,000 samples taken within the past month from birds killed by hunters, with most of those coming from Whatcom, Skagit and Clark counties, according to Don Kraege, waterfowl section manager for the Washington state Department of Fish and Wildlife.
Highly pathogenic means the strains also can be deadly to domestic chickens and turkeys.
Wild birds, specifically waterfowl, carry the flu but don’t show symptoms. So sampling focused on wild ducks, especially the top four killed by hunters: green-winged teals, widgeons, mallards and northern pintails.
The sampling started after tests found two highly pathogenic strains in wild birds in Whatcom County last month. Testing was stepped up here after Canadian inspectors first confirmed the highly pathogenic H5N2 strain at two British Columbia poultry farms in the first week of December.
The week after that, fish and wildlife officials tested two birds found dead in Whatcom County. One was a northern pintail duck, which actually died because of aspergillosis, a fungal disease that birds can contract from eating moldy grain in fields and farm yards. But the duck also carried a strain of bird flu similar to the one that caused the outbreak in B.C.
The other was a captive gyrfalcon used for hunting and fed a wild widgeon, a type of duck, by its owner. Testing showed an H5N8 strain of the virus in the gyrfalcon. The bird was one of four captive gyrfalcons fed the widgeon. All died after, but just one was tested.
Both the wild pintail and widgeon were traced to the Wiser Lake area.
It marked the first time wild birds in North America were found to have highly pathogenic bird flu, and raised concerns for domesticated backyard flocks that come into contact with wild birds in Whatcom County and other parts of the state.
“It was a huge finding that had never occurred before. That raised all kinds of alarms as far as impacts to backyard poultry farms,” Kraege explained. “We know it’s in the population now, but how prevalent is it?”
An analysis of the samples could be completed this week and provide answers to that question.
Because of the possible impact on backyard flocks, state and federal agriculture officials have urged poultry owners to keep their birds from coming into contact with wild birds, especially since migratory waterbirds — ducks, geese and shorebirds — are migrating south from Alaska along the Pacific Flyway.
Officials stress that the highly pathogenic strains don’t seem to be dangerous to people and that they haven’t been found in commercial poultry in the U.S. or Washington state.
Wildlife officials have documented the prevalence of low-pathogenic strains, which are common in waterfowl.
Fish and wildlife officials tested more than 10,000 wild birds for bird flu viruses from 2005 to 2011. They found the viruses in about 10 percent of all birds tested, but noted that none caused illnesses or deaths.
What is worrying officials this time around is the gyrfalcon death.
“With avian influenza, water birds have evolved with that over many years. Similarly the things that eat those ducks have evolved with those viruses too,” Kraege said, so officials expected more resistance from the raptor.
Still, he said, there have been a couple of cases of raptors in Europe and Asia that died from the same kind of virus.
“It’s unusual but it has happened before,” Kraege said.
Still, it’s a concern because raptor numbers are lower than those of waterfowl.
Meanwhile, wildlife officials continue to encourage the public to contact them if they find dead or sick wild birds, especially raptors.
“We’re looking at raptors more than we typically would,” Kraege said.
Sick or dead wild birds can be reported by calling 1-800-606-8768.