127 



likely to be shot and have their stomachs examined. Hence there is a 

 certain amount of unfavourable selection against the species as a whole 

 in the choice of evidence, that should be allowed for. 



The species is, on the whole, exceedingly useful and does considerably 

 more good than harm. Individuals, however, frequently get into the habit 

 of regularly visiting the poultry yard. These are nearly always young 

 birds of the year in search of easy prey. The old birds are usually too 

 cautious for this. There can be no question that such individuals should 

 be eliminated as quickly as possible, but it certainly cannot be maintained 

 that a generally useful species should be systematically persecuted for the 

 bad habits of a few. In economic ornithology it is a good rule, when the 

 evidence is evenly balanced, to give the bird the benefit of the doubt. 



339. Red-shouldered Hawk. CHICKEN HAWK. FR. LA BUSE A MANTEATJ nonx. 

 Buteo lineatus. L, 18-30. Plate XIII B. 



Distinctions. The reddish underparts of the adults. Juvenile plumage may be similar 

 to the young Red-tailed, but its inferior size and an indication of rufous on the shoulders 

 or wing-coverts and the spotting of centre of breast will distinguish it. 



Field Marks. With its characteristic Buteo outline and habits it is not likely to be 

 confused with any other species than the Red-tailed. The lack of red tail and the ruddy 

 underparts will distinguish adults. For juveniles the voice and size are probably the most 

 reliable guides. The notes of this species are so like certain calls of the Blue Jay that they 

 can be differentiated only with difficulty. The Red-tail's screams are 01 similar nature, but 

 quite distinguishable. 



Nesting. In trees, 35 to 75 feet from the ground. 



Distribution. Over eastern North America north to the limits of settlement. Breed 

 in Canada wherever found. 



SUBSPECIES. Several subspecies of the Red-shouldered Hawk are recognized, 

 but only one, the Eastern Red-shouldered, the typical form, occurs in eastern Canada. 



This is probably the most common Hawk in eastern Canada. It is 

 similar in habit to the Red-tailed except that it does not insist upon deep 

 woods for its nesting habitat but will build in almost any little patch of 

 woodland, sometimes in surprising proximity to settlement. 



Economic Status. This species is, fundamentally, very similar in its 

 food habits to the Red-tailed, but being a much smaller and lighter bird 

 the damage it can do is proportionately less, whereas its good offices are 

 scarcely if at all impaired. Of 206 stomachs examined, 3 contained 

 poultry; 12, other birds; 102, mice; 40, other mammals; 20, reptiles; 30, 

 batrachians (frogs, etc.); 92, insects; 16, spiders; 7, crawfish; 1, earth- 

 worm; 2, offal; and 3, fish. It will thus be seen that its diet is varied. 

 Whether the shrews, frogs, reptiles, and spiders are to be counted for or 

 against the species is open to argument, but the large number of mice 

 and insects against 3 of poultry and 12 other birds obviously acquits the 

 species of the charge of doing much damage. 



342. Swainson's Hawk. FR. LA BUSE DE SWAINSON. Buteo swainsoni. L, 20. 

 Of about the same size as the Red-shouldered. It may occur either in a nearly black 

 phase, a light one, or any intermediate stage. The characteristic light plumage 

 shows an evenly brown back, head, and upperparts, white underparts with a band of 

 vinaceous across the chest, and slight indications of bars of same colour on flanks. 



Distinctions. Many birds have the ends of their primaries suddenly reduced in 

 width as if a shaving had been taken from the edge with a pocket-knife. In this 

 species the three outer primaries are thus attenuated or emarginatedr In the Red- 

 shouldered Hawk, for which certain plumages might be mistaken, four of the primaries 

 are thus emarginated. 



Distribution. The prairie provinces and westward. North to the Arctic, wandering 

 casually to the lower Great Lakes. 



