Any of about 11 species of hawks (subfamily Circinae; family Accipitridae) that are plain-looking, long-legged, long-tailed, and slender. Harriers cruise low over meadows and marshes looking for mice, snakes, frogs, small birds, and insects. They are about 20 in. (50 cm) long and have a small beak and face feathers that form a facial disk. They nest in marshes or tall grass. The best-known harrier is the marsh hawk (Circus cyaneus), commonly called hen harrier in Britain, which breeds in temperate and northern regions throughout the Northern Hemisphere. Other common species are found in Africa, South America, Europe, and Asia.