The agency says it's not known how many birds or which companies are involved.
Spokesman Ryan Bartlett says the regulator started getting the reports early Tuesday afternoon, and staff was sent to the area to ensure companies were responding appropriately.
He also says the birds have come into contact with other oilsands infrastructure near Fort McMurray, but doesn't give any details.
Syncrude, which operates one of the biggest oilsands sites north of Fort McMurray, was fined $3 million for the deaths of more than 1,600 ducks when they landed on its tailings pond in 2008.
And in October 2010, more than 550 birds had to be destroyed when an early winter storm forced the birds to land on the toxic waste ponds belonging to Syncrude and Suncor.
No charges were laid in that incident.