Top 200 most commonly encountered species in NA

This list is according to the book Birding.

Rock Pigeon
The highly variable city pigeon; multicoloured birds were developed over centuries of near domestication. Flocks in flight show a wide variety of plumage patterns. They have become extremely tame. This tameness provides many opportunities for observing interesting aspects of bird behaviour.

Band-tailed Pigeon (western North Americana) is bigger, has grey rump, plain upperwings, yellow bill and white collar.