Wild birds showing more symptoms from Avian Influenza, populations not believed threatened

Researchers across North America are seeing more serious symptoms among sick birds from this year's highly pathogenic Avian Influenza strain, but population level impacts are not expected.

The virus is mostly being spread by migrating waterfowl, particularly snow geese, as they return to their northern nesting grounds.

"Often they're carrying it and don't get particularly sick," said Dr. Dayna Goldsmith, with University of Calgary's school of veterinary medicine. She also serves as regional director of the Canadian Wildlife Health Cooperative.

"One of the differences we're seeing with this current strain is more birds are getting symptomatic with it and dying from it."

Among the significant symptoms in affected birds are signs of neurological problems, including head tremors, an inability to hold their head and neck properly, swollen eyes and walking in circles.

Avian Influenza can in theory pass to humans, but the risk of transmission is generally considered to be quite low. People should avoid handling dead or sick birds, and should wash their hands and clothes if they do come in contact.

The greatest risk is economic. So far 12 Alberta poultry farms have had outbreaks identified by the Canadian Food Inspection Agency and hundreds of thousands of birds have been euthanized in the province.

Wild birds have existed with the virus for a very long time and have a good level of immunity, even with the more serious strain. But Alberta's wildlife disease specialist Dr. Margo Pybus said it remains to be seen what will happen when the massive flocks of snow geese congregate in their Arctic nesting grounds.

Snow geese populations have boomed in recent years, over-grazing and damaging the habitat around their nesting areas. Pybus said it's possible the current strain is simply nature re-establishing balance.

"Snow geese as a whole are better off for having fewer snow geese, and maybe this is Mother Nature's way of using influenza as a tool to do that," Pybus said.

She also said there are reports coming from other jurisdictions of raptors, particularly bald eagles, becoming infected from scavenging the carcasses of dead waterfowl. She said one obstacle to inspecting and testing dead waterfowl is how quickly eagles, hawks and coyotes erase the evidence.

The province is looking for reports of sick birds, but does not want to collect every dead duck or goose people come across.

If you see a flock of geese take off but some are left behind, unable to get off the ground, or if several dead birds are spotted in close proximity to each other, note the date, time, species and specific location and report it to Alberta Environment and Parks at 310-0000.