194 BIRDS OF ONTAEIO. 



Genus CIRCUS Lacepede. 

 CIRCUS HUDSONIUS (Linn.). 



139. Marsh Hawk. (331) 



Adult male: — Pale bluish-ash, nearly unvaried, whitening below and on 

 upper tail coverts; quills, blackish towards the end. Length, 16-18; wing, 

 14-15; tail, 8-9. Female: — Larger; above, dark brown, streaked with reddish- 

 brown; below, the reverse of this; tail, banded with these colors. Immature 

 male is like the female, though redder, but in any plumage the bird is known 

 by its white upper tail coverts and generic character. 



Hab. — North America in general, south to Panama. 



Nest, on the ground, composed of twigs and dried grass. 



Eggs, four or five, pale greenish-white, sometimes spotted faintly with light 

 brown or lilac. 



In Southern Ontario the Marsh Hawk in the red plumage is a well- 

 known bird, but in the blue phase it is seldom seen. It arrives from 

 the south in April, as soon as the ice is gone, and from that time till 

 November it may usually be seen coursing over the marshes and 

 moist meadows in search of its food, which consists of mice, small 

 birds, snakes, frogs, worms, etc. It breeds sparingly at the St. Clair 

 Plats, becoming quite numerous in the fall on the arrival of those 

 which have bred farther north. 



It is one of our most abundant and widely dispersed birds, being 

 found throughout the whole of North America. In Ontario it is 

 found breeding in all suitable places. Dr. Bell mentions its occur- 

 rence at Hudson's Bay ; it is common among the marshes in the 

 North- West, and also appears in Alaska. One of the most remark- 

 able characteristics of this species is its habit of turning somersaults 

 in the air, which is thus described by Mr. Nelson : " While I was at 

 the Yukon mouth, on May 19th, 1879, a pair of hawks was seen 

 repeatedly crossing the river on different days at a certain point, the 

 leader always performing, as he went, a succession of curious antics. 

 He would turn over and over half a dozen times in succession, Hke a 

 Tumbler Pigeon, and after descending nearly to the ground he would 

 mount to his former height and repeat the performance, so that his 

 progress became a perfect series of these evolutions. The other bird 

 always flew slowly and smoothly along, as if enjoying the performance 

 of its companion." Nearly all of those seen in Southern Ontario 

 are in the brown plumage, and I have never observed one of them 

 indulge in the eccentricities above described. It may be that they 

 are peculiar to the old male in the blue dress. 



