162 



THE OOLOGIST 



inches in length; the forked tail is 

 about half as long as the wing. This 

 species lacks the spiny tail feathers 

 of the Vaux Swift (Chaetura vauxi), 

 which is sometimes found during the 

 late fall in company with our bird. 

 As has been stated before, the White- 

 throated Swift is preeminently a 

 mountain-loving species, nesting in 

 what are known as the Upper Sonoran 

 and Transition Zones. Where some 

 high bare-faced cliff rears its cresJ: 

 above the cool canyon depths, and 

 there is little or no evidence of human 

 existence, you are likely to find a col- 

 ony of these birds, dashing and wheel- 

 ing in mid-air, darting in and out of 

 the nesting rannies; all the while 

 twittering incessantly in their pecu- 

 liar high-pitched voice. 



But few birds can compare with this 

 Swift in powers of flight. He seems 

 to be forever on the wing, now diving 

 like a plummet straight down the 

 mountain side, now shooting up into 

 the bright sunlight with the speed of 

 a rocket, pursuing his insect prey with 

 almost incredible rapidity, or restless 

 ly darting in and out of the crevices 

 in the rock that perhaps conceals his 

 nest. 



The bird is a comparatively late 

 breeder in this vicinity, starting to 

 build about the middle of May, and 

 fresh eggs may be found from the last 

 week in May to the latter part of June. 

 The Swifts are always gregarious, 

 from six to fifty pairs nesting to- 

 gether. As they are somewhat erratic 

 in their choice of a nesting site a 

 cliff that shelters a large colony one 

 year may be entirely deserted the fol- 

 lowing summer. 



The nest is usually situated in some 

 inaccessible crack or pocket in the 

 face of a high cliff. It is no mean task 

 to swing down fifty or a hundred feet 

 at the end of a rope and try to get at 

 ?- nest placed three or four feet back 



in an opening perhaps only three 

 inches in width, and usually all but 

 concealed from view by some project- 

 ing point of rock. 



Vegetable fibers, straws, and large 

 feathers are used in the construction, 

 cemented together and to the rock by 

 the bird's saliva. The nest forms a 

 rather small shallow basket, irregular 

 in shape to conform with the require- 

 ments of the particular cranny in 

 which it is placed. There is seldom 

 any lining added, at most a few soft 

 feathers are glued to the inside. 



The eggs are from three to five in 

 number, pure white, and average about 

 .84x.50 inches. Very frequently one or 

 more eggs in a set are damaged by 

 being struck with bits of rock dis- 

 lodged from above the nest. 



Sometimes the Wliite-throated Swift 

 will be found nesting about some old 

 mission or deserted adobe ranch 

 house, but as a rule he does not take 

 kindly to conveniences provided by 

 man, preferring the secluded cliffs of 

 his forbears. 



To this brave bird I offer the fol- 

 lowing verses which will perhaps bet- 

 ter express my sentiments than the 

 preceding cold prose. 

 Hail! You wild thing on restless wing, 



Free pilot of the air. 

 You dart on high 'midst peaks that lie 



Above our valleys fair. 

 You scorn the strife of urban life. 



The flatness of the plain. 

 Along the marsh and desert harsh 



We look for you in vain. 

 But far on high where earth and sky 



Are blended as in one; 

 Where pinnacles kissed by storm- 

 racked mist 



Each morning greet the sun. 

 Where icy stream 'neath cliff does 

 gleam 



And speckled trout to play, 

 'Tis there you swing on flashing wing 



Along the rock-walls gray. 



