With the arrival of migration season, Canadian birds face a possible new wave in their own pandemic.
H5N1, the avian flu strain, now prevalent in Alberta and throughout Canada, is negatively affecting wild bird populations.
“Waterfowl are the biggest wild bird species that are affected, so geese, some ducks, and then animals that prey on those species,” said Kyle Edworthy, an educator at the Inglewood Bird Sanctuary and Nature Centre in Calgary.
The sanctuary hosts over 12 different kinds of waterfowl, as well as many birds of prey, such as great horned owls, hawks, and bald eagles. All are species susceptible to the avian flu.
“It works its way up the food chain,” Edworthy said. “They’re not picky about what they can find. They eat an animal that’s been infected, and they will also get infected.
“There are some birds that seem to be more susceptible to the virus,” said Matt Dyson, a research scientist at Ducks Unlimited, a Canadian wetlands conservation organization. “Some of our scavenger birds like red-tailed hawks or owls, even some gull species, ravens, crows – they might be at risk for some higher rates of mortality.”
While data shows that birds that prey on other avian species are harshly affected by this strain of flu, waterfowl have a higher chance of carrying the disease.
“A lot of waterfowl are carriers of the virus, but they’re not necessarily known for having high rates of mortality due to the virus, so they can be silent carriers of it,” said Dyson.
When many waterfowl gather together during migration periods, this can result in higher numbers of infection.
“There’s potential during the fall migration to see increases in the infection rate just given the fact that, from a waterfowl perspective, you start to get a concentration of birds,” he said.
These large groupings during migration can cause a spike in cases, especially after the breeding season when young birds are added to the mix.
“If it’s been a good year for reproduction, you get a bunch of immunologically naive individuals, so they haven’t had the virus before – they haven’t been exposed to it,” he added. “Now, all of a sudden, they migrate back south, and they concentrate in areas.”
With this growing concern for bird health during the fall, there are measures Albertans can take to look out for the local bird populations. Edworthy advised against putting up bird feeders this season as they can be a virus transmission hot spot.
Ensuring that any birds that have succumbed to the virus are cleaned up properly will also help stop the virus from spreading further.
Dyson encourages citizens to be vigilant observers and report dead birds to local authorities. Albertans can report these occurrences to the Alberta Environment and Parks/Fish and Wildlife Enforcement Services’ toll-free helpline at 310-0000 or via the Canadian Wildlife Health Cooperative (CWHC)’s online reporting tool.
