Yes, a pigeon CAN be a champion, because the NPA holds a yearly exhibition to select the best of the best.
The NPA 2010 Grand National was held in Salt Lake City Utah. There were 3,721 entries representing 26 breeds. Exhibitors came from every state in the USA and Canada.
These pigeons are NOT your average scavengers, you know. Twisted Sifter, in "Bizarre Gallery of Grand National Champion… Pigeons!?!" has collected 30 photos of some of the winners from the Grand Nationals.
Below are a couple of my favorites.