There isn’t one…yet. Right now the leading candidate appears to be the Gray Jay or Whiskey Jack or even “Canada Jay” which was one of its older common monikers. Here’s an NPR report on the flap over “national bird.”
Here are some of my better Gray Jay photos, all taken in Jackson County, Oregon, far south of the Canadian border.
Why not Canada Warbler, Canada Goose or Great Gray Owl. They get my vote which doesn’t count as I am on the wrong side of the border.