New England is prime breeding grounds for broad-winged hawks, who disappear to South America en masse for the Winter. In the Fall, you can watch huge flocks flocks of them ("kettles") using pockets of hot air ("thermals") to spiral up into the air so they can get better altitude for their migration flight (which averages out to around 4,000 miles!). In the Spring, they return in scattered groups to their breeding grounds and all of a sudden, you see these great little hawks hanging out on utility wires.
Aside from color, you can generally tell a broad-wing by the length of its tail. If you see a hawk on a utility wire that's got a tail which is about the same length as its wings or not much longer, it's probably a broadie. If it's got a much longer tail, you're more likely dealing with a cooper's hawk or a sharp-shinned.
As usual, the picture is a thumbnail, linking to a picture double its size.