36 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



A pair of Barn Owls (Tyto alba pratincola) flew from the same cliff. 

 The female Prairie Falcon broke the wing of the female owl, and the 

 male falcon killed the male owl outright, each with a single stoop." 



Although I have long known that this falcon likes to chase and 

 hector large birds, I still wonder why it chooses the great blue heron 

 so often. Is it simply because of the size of the heron and its very 

 evident fear of the falcon? Ellsworth D. Lumley writes us: "These 

 birds seem to take delight in annoying the herons, for I watched 

 one of them as he repeatedly dived toward a heron that was standing 

 on the rock cliff, coming to what appeared to be inches of the heron's 

 head. The heron always ducked and lowered himself as the falcon 

 sped by. The herons were also attacked when flying by the falcons, 

 although I never saw one of them struck." Like Mr. Lumley, I 

 have never seen a great blue heron actually struck by tins tormentor, 

 but the falcons I have seen seemed to take a positive delight in seeing 

 how closely they could sweep and in how loudly they could make 

 the herons shriek. 



In spring falcons are keen, dashing, and wary, beautiful to see as 

 they dart across the country. But in autumn they may be seen at 

 times hunched up, like a clod, on some bare limb or pole. If startled 

 then they may only fly negligently a few hundred feet and may 

 even show entire indifference to a person's presence. Usually they 

 catch their food by dashing, lightninglike swoops that are the very 

 essence of grace and wildness. At other times they may be seen 

 hopping on the ground or across the grass, like small fowls after 

 grasshoppers. They may be seen over low plains and deserts, or 

 they may be up over snow-clad mountains. Tyler (1923) says: 



A moody creature at all times, peevish and whimsical, the Prairie Falcon is a 

 bird of extremes. One never knows just what to expect from this handsome 

 falcon and the expected seldom happens. He may fairly dazzle us with a burst 

 of speed as he comes in to his nest cliff from a long flight over the sage-covered 

 ridges ; but our admiration fades as we behold him stoop-shouldered and motionless, 

 for an hour at a time, on some low mound in a pasture, a picture of listless dejection. 



A pair of ravens in a nest not fifty feet from the falcons' own pot hole may be 

 tolerated for days at a time with no act to indicate that the falcons are even aware 

 of the presence of their neighbors. Then a sudden outburst of anger, totally un- 

 provoked so far as the human eye can detect, may mark the beginning of merciless 

 and unceasing persecution. * * * 



Sometimes the canyons echo with her noisy cackling as the female falcon strikes 

 again and again at the observer who approaches her nest cliff and yet, when, upon 

 a return visit, we expect the same thrilling demonstration, she often flaps silently 

 away with all the cramped awkwardness of a sparrow hawk just aroused from the 

 duties of incubation. 



With a roar of wings the male sweeps along a canyon wall, dashes into a feeding 

 flock of quail, snatches a victim and beats away like some giant swift; but when 

 we hope to see this marvelous exhibition of flight repeated, we find him hopping 

 around sparrow-like on the ground in some summer fallow field scrutinizing the 

 bunches of stubble for a chance hidden meadowlark or Savannah sparrow. 



