18 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



swooped at it again and again, each time clearing the duck by a foot or more. 

 After this it alighted on the ice about eight feet from the duck and remained 

 there motionless for a few minutes. The mallard quacked continuously but did 

 not move from its position. The falcon then rose and again began swooping at 

 the duck. By this time my companion and I were walking toward the pond, 

 one on either side and several hundred yards apart. When distant from the 

 pond about 75 yards the mallard rose and flew toward Okanagan Lake and the 

 falcon, passing close to my companion, was shot. 



In the crop of the gyrfalcon were approximately two ounces of flesh from the 

 breast of a male mallard, identified by the presence of the characteristic chestnut- 

 colored breast feathers. 



It is likely that the gyrfalcon was attempting to induce the mallard 

 to fly, as the larger falcons seem to prefer to strike down their victims 

 in the air, rather than pounce upon them on the ground ; but, as these 

 birds usually do not eat oftener than once a day, and as it already 

 had considerable food in its crop, it may have been merely playing 

 with the duck. 



FALCO MEXICANUS Schlegel 



prairie falcon 

 Plates 5-10 



HABITS 



Contributed by Milton Philo Skinner 



The prairie falcon is a close counterpart of the lanner falcon (F. 

 biarmicus jeldeggii) of Europe. It is also the prairie and desert cousin 

 of the duck hawk, which it closely resembles with its pointed wings 

 and its dash and courage, although it preys more on small mammals. 

 Possibly this mammal-catching is due to the falcon's marked prefer- 

 ence for the open spaces where the rodents live. In certain sections 

 both the prairie falcon and the duck hawk occur, and there the two 

 can be distinguished from each other by the uniformly lighter color 

 of the falcons. The falcon is the same size as the duck hawk and 

 larger than the American sparrow hawk, which it resembles in some 

 of its habits. It ranges, normally, east to the Missouri River, occa- 

 sionally to Minnesota and even to Illinois. It is particularly abun- 

 dant in eastern Washington and Oregon and in the coast ranges that 

 lie west of the great central Californian valleys. Yet, in California, 

 it is seldom out over these level valleys but prefers the rough, broken 

 foothills. This is easily understood when we find that the prairie 

 falcon markedly prefers a nesting site in a cavity, or in a crevice, in 

 the face of a cliff. Its range reaches only a little over the inter- 

 national boundaries into British Columbia and Alberta on the north 

 and into the Mexican highlands on the south. At the present time 

 it is rather rare over much of the range east of the Rocky Mountains, 

 and it is steadily growing rarer everywhere. 



