The American Kestrel is a very small falcon, one of the smallest of the common falcons. At maturity, they will generally weigh only four ounces and measure nine to twelve inches in length. The only smaller Falcon is the Seychelles Kestrel, which is found in Europe. Like all falcons, they have distinct falcon facial markings including the 'mustache' and 'sideburns'. On the American Kestrel these markings are black or dark brown. The Kestrel is easily distinguished by the presence of double black stripes on a white face. Their backs and tails are decorated with rust plumage. They are the only falcons to have rust colored backs. The tail is relatively long with a much narrower tip and is marked by terminal black barring. They have dark eyes with a dark vertical line running through them, unfeathered legs, white chin and cheek patches, and a notched beak. Their heads have blue plumage on the tops with a rust colored cap. Male and female American Kestrels can be easily distinguished by their different markings. The male Kestrel has grayish blue wings, while the females are rust colored. The rusty head cap is generally brighter in males than in females. The male also has very distinct color markings, which are uncommon among raptors. The male has a buff colored chest with small black spots on the side. Both American Kestrels have long slender wings, with underside plumage light brown with darker brown streaks. Females are generally larger than males.
