This is probably right. Raising and competitive flocking of pigeons was also once a pretty popular pastime.

There's a flock that hangs out on the roof of a house a couple of doors down from me. Dollars to donuts they are the descendants of a flock someone raised there.

I'm not a fan, they are ugly, spread disease, eat food meant for wild birds, and are just generally loathsome. But I wouldn't kick them, either.