I remember huge flocks of ‘em in NYC when I worked there, in the late-70s and thru the 80s. Pigeon crap was awful, especially in Midtown. People in Central Park either sat in it or got it dropped on them. Nothing like sitting on a park bench, surrounded by 1,500 aggressive pigeons, while eating lunch. I don’t know how they did it, but they were there, day after day.