The Prairie Falcon 



for we had invaded their sanctuary for the second time and were on the 

 retreat, thoroughly baffled, when a vagrant impulse seized me to fire a 

 pistol back and some two hundred yards away, at a last year's raven's 

 nest set high against a rock wall. The celerity with which a male Prairie 

 Falcon abandoned five perfectly good eggs of the rare 'white' type was a 

 balm to wounded spirits. 



"In another canyon a male Prairie Falcon keel-hauled a passing 

 eagle, and I marked his approximate range of interest upon his return in 

 lordly mood. There were many possibilities, but I tried first a likely- 

 looking old raven's nest a hundred yards away. The effect was electrical. 

 Out shot a female Prairie Falcon as though touched by the bullet; and 

 when she had caught her breath, she filled the air with fierce aspersions, 

 perhaps pardonable under the circumstances. 



"The ascent was tedious and the sun torrid; but the descent over a 

 conglomerate escarpment some ninety feet in height was rewarded by a 

 set, 1/4, of the darkest eggs of this species which I have ever seen, so dark, 

 indeed, that I first exclaimed 'Duck Hawk!' incredulously. The amiable 

 birds did not omit to offer comments anent my skill as a rope artist; and 

 the female made some beautiful swoops at my head — always a solace under 

 such circumstances. Ah, me! What a rascal is the oologist who enjoys 

 such objurgations! But I'll own to it. And as the indignant lady 

 stood upright in her empty cell, I turned and blew her a kiss and promised 

 to come back another year." 



The exact choice of nesting sites varies interminably from "potholes" 

 and crannies to more pretentious caves, or even open ledges. The chief 

 requirement is inaccessibility, especially as regards four-footed prowlers. 

 The birds scarcely fear the intrusion of feathered marauders, I guess, 

 though I do recall having once seen a Barn Owl which lighted, possibly by 

 accident, upon a ledge which a Prairie Falcon had just quitted, and which 

 contained four fresh eggs. The owl stood her ground, too, in spite of a 

 furious onslaught, and the advantages seemed to lie with the night bird 

 so long as she had a wall to back her up. Anyhow, the falcon withdrew 

 a few rods and the owl slipped away, hugging the cliff so tightly that the 

 falcon did not dare to strike. A south exposure is oftenest favored and 

 there seems to be no particular effort on the part of the sitting bird to 

 avoid the glare of the sun. Unseasonable rains, however, do sometimes 

 cause her discomfort, and, more rarely, loss. 



The first two weeks in April are the golden weeks for Falcon nesting 

 in the cattle country. Evidently many sets are complete by April first, 

 for we found one far advanced in incubation on the 19th, and another 

 hatching on the 22nd. If robbed early in the season, second sets are 

 almost invariably laid in a new but closely related situation. 



1622 



