U.S. conservationists are using an obscure American trade law to pressure Canada over how they manage the oilsands.

An environmental coalition has filed an application under what's known as the Pelly amendment.

It allows the U.S. government to consider trade sanctions against any country that's weakening efforts to conserve endangered species.

The coalition says Alberta's management of the oilsands is harming woodland caribou, whooping cranes and dozens of other migratory birds.

The U.S. secretary of the interior must determine if the activities described are hurting endangered species, and then inform the president, who may take action including trade sanctions.

The amendment has been mostly used against whaling nations such as Norway, where it is credited with helping force that country to change its rules.