National Museum, 53; Museum Comp. Zoöl., 24; Boston Society, 8; Philadelphia Academy, 10; Cab. of G. N. Lawrence, 5; R. Ridgway, 6. Total, 106. _Measurements._ +----+-----------+-----------+---------+---------+-----------+----------+ |Sex.| Wing. | Tail. | Culmen. | Tarsus. |Middle Toe.|Specimens.| +----+-----------+-----------+---------+---------+-----------+----------+ | ♂ |12.90–13.85| 9.90–9.80| .60–.65|2.85–2.90| 1.20–0.00| 34 | +----+-----------+-----------+---------+---------+-----------+----------+ | ♀ |13.00–16.00| 8.80–10.50| .70–.75|2.85–3.25| 1.22–1.55| 32 | +----+-----------+-----------+---------+---------+-----------+----------+ HABITS. The Marsh Hawk is one of the most widely distributed birds of North America, breeding from the fur regions around Hudson’s Bay to Texas, and from Nova Scotia to Oregon and California. It is abundant everywhere, excepting in the southeastern portion of the United States. Sir John Richardson speaks of it as so common on the plains of the Saskatchewan that seldom less than five or six are in sight at a time (in latitude 55°). Mr. Townsend found it on the plains of the Columbia River and on the prairies bordering on the Missouri. The Vincennes Exploring Expedition obtained specimens in Oregon. Dr. Gambel and Dr. Heermann found it abundant in California. Dr. Suckley’s party obtained specimens in Minnesota; Captain Beckwith’s, in Utah; Captain Pope, Lieutenant Whipple, and Dr. Henry, in New Mexico; and Lieutenant Couch, in Tamaulipas, Mexico. Dr. Woodhouse met with it abundantly from the Mississippi River to the Pacific Ocean, throughout the summer, showing conclusively that it breeds in those different sections of country. De la Sagra, Lembeye, and Dr. Gundlach, all give it as a bird of Cuba, but not as breeding there. Dall records it as very rare on the Yukon, and an occasional summer visitor only at St. Michael’s, where an individual was killed as late as November. Donald Gunn states that it makes its appearance in the fur countries about the opening of the rivers, and departs about the beginning of November. It preys upon small birds and mice, is very slow on the wing, flies very low, and in a manner very different from all other kinds of Hawks. In Nova Scotia it is very abundant, and is very destructive of young game. Mr. Downes regards it as an indiscriminating feeder upon fish, snakes, and even worms. He took two green snakes from the stomach of one of them. [Illustration: _Circus hudsonius_ (male and female).]