American Crow

Four subspecies are recognized. They differ in bill proportion and form a rough NE-SW clinal in size across North America. Birds are smallest in the far west and on the south coast.[5]
Corvus brachyrhynchos brachyrhynchos – Eastern Crow: northeastern United States, eastern Canada and surroundings. Largest subspecies.
Corvus brachyrhynchos hesperis – Western Crow: Western North America except arctic north, Pacific Northwest and extreme south. Smaller overall with a proportionally more slender bill[6] and low-pitched voice.
Corvus brachyrhynchos pascuus – Florida Crow: Florida. Mid-sized, short-winged but decidedly long bill and legs.[6]
Corvus brachyrhynchos paulus – Southern Crow: southern United States. Smaller overall, bill also small.[7]