Falco columbarius
Order Falconiformes
Family Falconidae
Subfamily Falconinae
Other names: Pigeon Hawk
♂ Adult male.— Upper parts bluish-gray; under parts white, streaked with black, the throat lightly, the rest heavily.
♀ Adult female and Immature.— Upper parts brownish; under parts as in male.
Nest, in a hole in a tree, or in a tower.
Eggs, varying from white, with few markings, to deep buff, more or less speckled with brown.
The Pigeon Hawk is a somewhat rare migrant in New York and New England in April, September, and October, more common along the coast; it is an occasional winter visitant. When a student has thoroughly learned the difference in appearance and flight between the Sparrow Hawk [Kestrel] and the Sharp-shinned Hawk, between a Falcon with long, narrow wings, and an Accipiter with short, rounded wings, he will be able, if a good opportunity offers, to identify a Pigeon Hawk. If a small hawk has a powerful head and shoulders, long narrow wings reaching well toward the tip of the tail, and the rapid flight of a falcon, and yet has a brownish (not reddish-brown) or a slaty-blue back, it can be no other than the Pigeon Hawk.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)