Hawk in Panorama city.

I have seen Cayote in the city of Chicago.  And recently I saw an owl perching on my fence.  It is noteworthy to mention animal sightings that I do not expect to seen in an urban setting.  In fact, just yesterday, I saw a hawk sitting by the side walk with a kill (pigeon I think) lodged between its claws.  Evidently, this hawk just caught the bird and I do not know really why it won't just fly off with its kill.  Too heavy perhaps?  Too tired and still resting?  Your guess is as good as mine.