Is this a Question Mark butterfly? It landed on my window hummingbird feeder, so this picture is through the glass. I didn't see the upper side of its wings when it left, since I was trying to get another picture when a hummingbird joined it at the feeder.

It sat there for a long time, and it was fun to see its tongue getting nectar then occasionally curling up. I had no clue what it could be, but after some searching, this is my best guess. I'm hoping one of the experts here can help! Thanks.