We don't normally have them in the area where I live - except in the city of Duluth. They apparently ride in by rail - in grain cars. Once, while working a construction job near the port terminal, we had so many of them around we began to catch them and eat them for lunch. We caught a few by hand, but the best method was:
Put a line of corn up to a two foot section of six inch stove pipe. Have an elbow on the end of the stove pipe. Once in the pipe, they couldn't make the 90 degree bend at the end of the stove pipe, and they couldn't back out because of their feathers.
We'd pluck the bird, and put it inside a section of pipe and cook it with an oxy torch. Made for an interesting lunch variety.
PG