My dad and I visited Muskegon County today and found an interesting Sterna tern at Pere Marquette Park. I'm under the impression this looks like a juvenile Arctic Tern. That said, I've only seen one juvenile Arctic Tern.
Lighting was very tough but with back-lighting, the transparent secondaries and inner primaries were evident, although I couldn't get this in a picture. To my eye, everything looks good for an Arctic Tern and I'm struggling to find any pro-Common Tern features. Comments appreciated.