Avian flu kills two endangered whooping cranes near Saskatoon

Two endangered whooping cranes found dead in fields near Saskatoon this fall tested positive for avian influenza, the first time the virus has been detected in the species’ wild bird population.

The first bird was found in October after biologists tracking the crane and its flock through GPS monitors noticed the tracker hadn’t moved in days.

Mark Bidwell, a wildlife biologist with the Canadian Wildlife Service, went out looking for the whooping crane and found its scavenged carcass in a field 90 kilometres east of Saskatoon.

“When you come across a dead bird, any bird really, you feel regret and worry. But when it's a species like this one it's more so,” Bidwell said.

More worry, perhaps, than with other species, because whooping cranes, which once numbered about 10,000 birds in Canada, were nearly extinct in the 1940s, with only 15 left alive.

Over-hunting and habitat loss contributed to the species’ near extinction, according to the Canadian Wildlife Health Cooperative (CWHC), a partnership of scientists and researchers from Canada's five veterinary colleges.

Conservation efforts and collaboration between American and Canadian scientists have helped grow the whooping crane’s population to about 560 wild birds that belong to the Aransas-Wood Buffalo population.

That flock migrates to the Gulf Coast of Texas for the winter and returns to Canada each spring to breed in Wood Buffalo National Park in northern Alberta and the Northwest Territories, according to the CWHC.

A member of the public found another dead crane about 100 kilometres northwest of the first, just as test results were confirming avian flu killed the first whooping crane.

Bidwell said it’s unlikely the birds caught the virus from each other.

“We think given the pattern of habitat use and the pattern of movements we see typically in these birds, it’s unlikely they were together in the days or weeks leading up to their deaths."

Instead, Bidwell said it’s more likely that the cranes caught the virus by sharing habitat with geese or other birds.

Avian flu is an overwhelming viral infection that attacks infected birds’ tissues causing neurological damage and death.

Trent Bollinger, a professor at the Western College of Veterinary Medicine and regional director and pathologist at the CWHC, said these are the first two confirmed cases of avian influenza in North America’s wild whooping crane population.