Canada

Burns said all influenzas mutate and the H5N1 strain that emerged in 2021 is "significantly worse than other strains that we've had historically."

She said the hope is that wild birds develop more immunity and the virus mutates into a less damaging strain.

Pandemic researchers worry that avian flu could mutate into a widespread human illness, and Bourque noted human transmission is "always a concern because these viruses can infect mammals, including humans, which is another reason why we don't want it in our domestic bird population — because it is a threat to humans."