Another species of raptor that seems to be joining the Peregrine, the Kestrel, and (at least in the Southwest) the Cooper’s as a city dweller is the redtail. This amazingly bold first year bird is apparently observing the habits of my sister Anita St John in her office on Beacon Hill in Boston (Mass General Hospital, Autoimmune Diseases; 5th floor, which doubtless helps the bird’s confidence).
And in New York City, where Pale Male reigns, here's, in all likelihood, one of his descendants.
http://imgur.com/Yp1A6Nk
I was working as a design consultant a few years back restoring a 100 years old two story building. There was an old piece of large rain gutter at the top of the building where pigeons would hold up in at times. The gutter was only about 15 ft long and pigeons would enter from either end. One day I was watching them and a rather small raptor flew in one end and all hell broke loose as pigeons left the other end. Finally the raptor emerged with a half eaten pigeon and flew away. He adapted well to city hunting.
Audwin