duck hawk

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. See peregrine falcon.

Century Dictionary and Cyclopedia

1. n. In England, the moor-buzzard or marsh-harrier, Circus œruginosus.
2. n. In the United States, the great-footed hawk or peregrine falcon, Falco peregrinus, var. anatum: so called from its habitually preying upon ducks. It is very closely related to and not specifically distinct from the peregrine falcon of the old world. It is a bird of great strength and spirit, a true falcon, little inferior to the gerfalcon in size, and about as large as the lanner or prairicfalcon. The female, which is larger than the male, is 17 to 19 inches long and about 45 in extent of wings. In both sexes, when adult, the upper parts are slaty-blue or dark-bluish ash, darker on the head, the sides of which have a characteristic curved black stripe; the under parts are whitish or buff, variously spotted or barred with blackish; the wings and tail are also spotted or barred; the bill is blue-black; the cere and feet are yellow, The duck-hawk is widely but irregularly distributed throughout North America; it nests indifferently on trees, cliffs, or the ground, and usually lays 3 or 4 heavily colored eggs.

GNU Webster's 1913

1. n. (Zoöl.) In England: The marsh harrier or moor buzzard.