Mass Goose Die-Offs in Manitoba Linked to Highly Pathogenic Avian Influenza
A surge in Canada goose deaths across southern Manitoba is raising concerns among wildlife officials, with a highly pathogenic strain of avian influenza – H5N1 – identified as the likely cause.
A recent discovery near Winnipeg revealed approximately 50 dead geese lying in the snow on the frozen Red River in Lockport, roughly 15 kilometers north of the city. This follows the removal of 165 goose carcasses from retention ponds in Niverville, about 20 kilometers south of Winnipeg, last week. Laboratory tests confirmed the Niverville geese succumbed to the H5N1 virus.
“We haven’t collected any of those carcasses [in Lockport] yet for testing, but just based on the number and the distribution, we suspect that the same disease is killing these birds,” a Canadian Wildlife Service biologist explained on Tuesday.
A History of Avian Influenza
First identified in Italy in 1878 as “fowl plague,” avian influenza has undergone continuous evolution, according to the U.S. Centers for Disease Control and Prevention. The current dominant strain, H5N1, emerged in China in 1996 and has since spread globally, impacting both avian and mammalian populations.
While birds have historically evolved alongside the virus, the current situation is unprecedented. “So the virus is something that the birds have evolved with, but it’s a bit of an interesting situation this year, because we haven’t seen this level of mortality in geese before,” the biologist noted. The concentration of dead birds in specific locations, such as Niverville and Lockport, is particularly rare.
Shifting Dynamics of the Virus
Historically, migratory birds carried the virus without significant harm, primarily transmitting it to domestic poultry, which often experienced severe illness. However, this pattern shifted dramatically in 2021 with the onset of widespread wild bird die-offs. Manitoba detected its first case in wild birds in the spring of 2022.
The Public Health Agency of Canada currently assesses the risk to humans from H5N1 as low. Canada has recorded only two confirmed human cases: one in 2014 involving a traveler who contracted the virus abroad, and another – the first domestically acquired case – in British Columbia in late 2024.
Despite the low human risk, officials urge caution. People should avoid handling dead birds and keep pets away from them. Scavengers are also being affected, with a provincial veterinary lab confirming H5 virus infections in coyotes, otters, foxes, ravens, crows, snowy owls, and bald eagles. Hunters are advised to pluck birds in well-ventilated areas, practice regular handwashing, and ensure thorough cooking.
Migration and Viral Spread
Many strains of avian influenza circulate among migratory species without causing widespread disease, but H5N1 is currently prevalent across Canada and globally. A spokesperson for Manitoba’s Department of Natural Resources explained in an email that wild birds – particularly geese, ducks, and shorebirds – play a key role in spreading the virus during spring and fall migrations, coinciding with the detection of new cases.
The geese observed near Winnipeg originate from diverse locations, including northern and southern Manitoba and as far as Nunavut, based on recovered banding data. To date, 726 dead birds have been tested in Manitoba this year, with 54 testing positive for H5N1.
“It’s definitely concerning because it’s not something we’ve seen before,” the biologist said. “I was down in Niverville and just seeing the number of dead birds on the several ponds in town was pretty striking. And in communication with other colleagues across Canada, just that number of dead birds in one area is not something that they’ve experienced either.”
The full impact on Canada goose populations remains unclear, with the latest banding data dating back to 2023. “It’s possible it’s having more of an impact in the last year or two than it has since it originally came in 2021.”
Factors Contributing to the Outbreak
The biologist explained that colder weather concentrates birds in remaining open water areas, facilitating rapid viral transmission. This is compounded by increased contact with ducks, considered the primary reservoir for the virus. Ducks possess a degree of background immunity from exposure to less virulent avian flu strains, which may explain the lower mortality rates observed in duck populations.
Anyone encountering sick or dead birds is encouraged to report them to the provincial TIP line at 1-800-782-0076.
