Avian flu outbreak affects wide range of species
A new outbreak of highly pathogenic avian influenza is spreading among wild birds in North America. While there are only a few reported cases in Western Alaska, the scope of the outbreak still has researchers concerned.
Until recently, avian flu was a problem almost exclusive to domestic poultry. Prior to 2002, there was only one outbreak of avian flu among wild birds, which occurred in South Africa in 1961. In the last 20 years, there have been multiple avian flu outbreaks in the wild bird population. Those outbreaks have occurred on every continent except Australia and South America.
The only prior avian flu outbreak to affect wild birds in North America happened in 2014, and according to Dr. Andy Ramey, a research geneticist with the U.S. Geological Survey in Anchorage, it had minimal impact on the wild bird population.
“There were some detections in wild birds but less than 100 in total. The number of species affected wasn’t particularly large, and there wasn’t a great deal of mortality observed among wild birds,” Ramey said.
What we’re seeing in Alaska now is very different.
“Now, here in 2022, we’re seeing large numbers of wild birds infected. As of (June 29), there’s been more than 2,300 detections in wild birds. … More than 80 species have been affected in the United States and Canada. And the mortality that we’re seeing isn’t enormous, but we are seeing many birds that are sick or that have died on account of this highly pathogenic avian influenza outbreak,” Ramey said.
The current strain of avian flu poses a low risk to public health, according to the Centers for Disease Control and Prevention. Only one human case has been reported in the U.S., in a worker directly involved in the culling of infected poultry. The infected individual reported mild fatigue as their only symptom, and recovered within a few days.
The greater risk with this outbreak is the threat it poses to conservation efforts.
“Some species that may occur in western Alaska, such as spectacled eiders, or Steller’s eiders, or emperor geese — the species with smaller geographic ranges and smaller populations — might be more susceptible to population impacts that could occur with increased mortality for something like highly pathogenic avian influenza,” Ramey said.
That means this outbreak could also negatively impact subsistence resources, though it’s not clear to what extent. Ramey pointed out there are many other causes of bird mortality, all of which fluctuate over time.
“We know some birds starve; there can be food availability (issues). There’s toxins in the environment. Something else that I’m sure you’ve heard about in the past is harmful algal blooms — that can be a source of mortality among wild birds. … So I think, often concerns become heightened when a source of mortality occurs more than we typically expect, or that we have grown accustomed to in recent history,” Ramey said.
Nome resident Brandon Ahmasuk observed what might have been the results of such a mortality event when he took a trip to Sledge Island in June and found an unusually low murre population.
“What we saw was about 25 murres when normally there’d be thousands, if not hundreds of thousands, of murres on the cliffs,” Ahmasuk said.
Ahmasuk speculated that Pacific cod coming up from the south might be out-competing the murres for food.
As of July 1, the state veterinarian has confirmed 85 cases of avian flu in Alaska. Of those, only three were in the Kusilvak Census Area and 10 in the Bethel Census Area. There have been no confirmed cases in the Nome Census Area, though there hasn’t been consistent testing in the region. Most of the cases in those regions were identified in gulls, but also included brants, a raven, a goose, a crane and a dunlin.
Both Ramey and Gay Sheffield with Alaska SeaGrant encourage all residents of the region to be on the lookout for birds behaving strangely, such as staggering or not flying away when approached. Anyone who observes such behavior should take photos and video if possible and contact the U.S. Fish and Wildlife Service Sick and Dead Bird Hotline at 1(866)527-3358.
Image at top: Dead seabird found on one of Nome’s beaches in 2021. Photo courtesy of Gay Sheffield, Alaska SeaGrant.