Snowy owls return to the prairies for the winter with new status as an endangered species.

Every year, snowy owls spread their wings and migrate to the prairies, where they enjoy access to abundant rodent prey in vast open spaces.

But this year’s migration is the first of its kind, marked by Recent classification of snowy owls as an endangered species,

That designation was announced in May by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), which assesses the at-risk status of native species and provides recommendations to the federal government.

Lewis Blight, an adjunct associate professor at Victoria University’s School of Environmental Studies and co-chair of the COSEWIC bird specialist sub-committee, said the decision to designate snowy owls as a threatened species was not taken lightly. But, he said, their population has declined by about 40 percent over the past 24 years.

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Blight said snowy owls face many challenges, including habitat loss in Arctic nesting grounds due to climate change. Rising temperatures are causing the sea ice to melt, reducing the number of platforms for the owls to perch on while hunting.

Snowy owls are also affected by avian influenza, Blight said — both becoming infected with it and losing their winter prey because of the virus. According to the , 15 cases of avian influenza have been found in snowy owls in Canada since 2021. data Compiled by the Canadian Food Inspection Agency.

Snowy owls face even greater challenges as they set out on their long migration southward. In their wintering grounds, they may be Kill by vehicles, Electricity by power lines, Tangled into human structures, and become Poison after eating prey that is exposed rodenticide,

Colin Weir, managing director of the Alberta Birds of Prey Foundation wildlife rehabilitation center in Coaldale, has dealt with raptors affected by them all.

“A lot of times when snowy owls come down from the Arctic … they’re coming into new areas with a lot of man-made threats,” Weir said.

The center cares for injured birds from across Canada, and is currently home to two snowy owls that were unable to be released after being hit by cars.

“The thing to remember about roadways is that they have ditches, which collect a lot of moisture and attract a lot of ground rodents,” Weir said. “So, that’s why birds get hit by cars. Roadside ditches are basically like buffet restaurants for them.”

Weir said the busiest time for bird collisions in Alberta is May to September, because that’s when most migratory birds of prey return from wintering farther south, but that’s not the case for snowy owls.

“Seeing wildlife in general is probably the number one thing,” Weir said. “Not only for the safety of the creatures, but also for people’s own personal safety.”

Snowy owls can be found in every Canadian province following their winter migration. NatureCounts, a biodiversity data platform run by Birds Canada, estimates there are 15,000 snowy owls in the country – more than half of the estimated global population of 29,000.

The International Union for Conservation of Nature classifies snowy owl populations worldwide as vulnerable.

Scientists say tracking snowy owl numbers is difficult

Snowy owls are particularly difficult to survey because of their nomadic nature, Lisa Takats Priestley said.

“They don’t have direct corridors,” said Priestley, a wildlife biologist who has been studying owl populations and movement patterns for more than 20 years. “They are very difficult to work with as far as trapping and banding.”

He said fitting transmitters to snowy owls has provided more information about their activity patterns, but does not confirm population changes.

Most of the data on snowy owl numbers comes from Christmas bird countingAn annual citizen science initiative in which thousands of volunteers across Canada count all the birds seen in a specific area.

Because snowy owl activity patterns are unpredictable, trying to track population trends based on visual counts may not be sufficient, Priestley said.

Due to their recent designation as a threatened species in Canada, there may be increased interest and effort from researchers to better understand snowy owl populations.

“Now that the snowy owl is listed, there will be an emphasis on using more data collected from different sources to help us understand where there may be greater concerns in certain parts of the owl’s range,” Priestley said.