119 

 Order Rap tores. Birds of Prey. 



General Description. Flesh-eating birds with four well-developed toes (Figures 31 

 and 32, p. 23), each armed with a strong sharp claw or talon for seizing and holding prey. 

 Bill is hooked (Figures 30, 33 a and b, and 34, pp. 23 and 24), and the base covered with 

 a swollen soft skin or cere in which the nostrils are situated. The Birds of Prey differ 

 from the generality of birds in that the females are considerably larger than the males. 

 This is probably due to the greater strain placed upon the female in feeding her young. 

 This greater responsibility, demanding strength, weight, and endurance rather than fine 

 technique, necessitates a higher development of these qualities in the female than in the 

 male who, while he may assist his mate, has not the final responsibility for the groiwng 

 family. 



Distribution. Raptorial birds are distributed over all the world except the Antarctic 

 continent, where their place is taken by the Skuas, Gulls, and other rapacious sea-birds. 



Though the classification of this order is far from satisfactory and 

 probably will be revised, American practice divides our species into three 

 suborders: Sarcorhamphi, the American Vultures, distinct from those of 

 the Old World; Falcones, the Diurnal Birds of Prey; and Striges, the 

 Nocturnal Birds of Prey or Owls. 



Economic Status. Perhaps no birds are better known and at the same 

 time so generally misunderstood in their economic relations as these. 

 All know of the Hawks, Owls, and Eagles and their flesh-eating propensities, 

 but few realize that amongst them are some of man's best friends and that 

 the popular policy of killing them indiscriminately is a mistaken one. Some 

 do considerable damage, but to include all in the condemnation merited by 

 the few is a grave economic error. The first family, the Vultures, are 

 repulsive birds, but as scavengers exceedingly useful, and no valid com- 

 plaint can be lodged against them. Of the other two divisions, the Diurnal 

 and Nocturnal Rapaces, their varying status is the cause of much miscon- 

 ception. Fortunately in regard to these birds we can speak with authority 

 based upon actual data and not mere speculation. The United States 

 Biological Survey made a thorough study of the food habits of American 

 Hawks and Owls, basing its conclusions upon the examination of some 

 2,700 stomachs taken in all seasons of the year in various parts of the 

 United States and Canada. The whole is embodied, with the data for its 

 substantiation, in a report, "The Hawks and Owls of the United States" by 

 Dr. A. K. Fisher. 1 Although compiled in and for an adjoining country all 

 Canadian species are treated and the results are as applicable to Canada as 

 to the United States. As some of the less harmful species do not occur in 

 Canada the following percentages should be slightly altered for our 

 use, but not enough to perceptibly modify the general conclusions. Only 

 six of the seventy-three species studied are injjrious. Of these, three are 

 extremely rare in Canada and one is altogether a fish-eater. Of the re- 

 mainder, 56 per cent of the stomachs examined contained mice and other 

 small mammals, 27 per cent insects, and only 3^ per cent poultry or game- 

 birds. Dividing the raptorial birds of eastern Canada into groups accord- 

 ing to their economic status we find that three species are wholly beneficial 

 and absolutely harmless; sixteen are mainly beneficial, doing decidedly 

 more good than harm; four are about balanced in their effect; and six are 

 positively harmful. Only three of these six are common enough to warrant 

 consideration and only two, the Sharp-shinned and Cooper's Hawks, 



J See also " The Hawks of the Canadian Prairie Provinces in Their Relation to Agriculture," 

 Geol. Surv., Can., Mua. Bull. 28, 1918. 



