278 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



is followed by a plumage as adult; adults apparently molt twice a 

 year, a complete postnuptial molt in autumn and a partial (possibly 

 complete) molt in spring."] 



Food. — Pearson (1911) quotes a letter from W. L. McAtee of the 

 United States Biological Survey: "The bird's food consists almost 

 wholly of insects, and beetles, flies and ants are the principal items. 

 It gets many beetles (Scolytidae), the most serious enemies of our 

 forests, when they are swarming, and takes also the old-fashioned 

 potato beetle {Lema trilmeata), the tarnished plant-bug {Lygus 

 pratensis).! and other injurious insects. The bird is, of course, largely 

 beneficial to the agricultural interests of the country." 



Knight (1908) says: "The food of the Chimney Swallow consists 

 of almost any of the smaller insects which fill the air of a summer's 

 day." 



Behavior. — The relationship between man and the chimney swift 

 is a rather curious one. Although the species spends the summer 

 scattered over a large part of the North American Continent, it never, 

 except by accident, sets foot upon one inch of this vast land. The 

 birds build their "procreant cradle" in the chimneys of thousands of 

 our homes and crisscross for weeks above our gardens and over the 

 streets of our towns and cities, yet, wholly engrossed in their own 

 activities far overhead, they do not appear to notice man at all. In- 

 deed, it is easy to believe that the swift is no more aware of man 

 during the summer, even when it is a denizen of our largest cities, 

 than when in winter it is soaring over the impenetrable jungles of 

 Central America. 



How do we regard this bird that does not know we are on earth? 

 We are glad to have swifts breed in our chimney ; we like to see them 

 shooting about over our heads, and we enjoy their bright voices, yet, 

 do we feel such friendship for them as we feel for a chipping sparrow, 

 for example, which builds sociably in the vines of our piazza? The 

 little sparrow may be wary, and may fly away if we come too near, 

 but at least it pays us the compliment of recognizing our existence. 

 The swift, however, is not even a semitrustf ul neighbor ; it is a guest 

 that does not know we are its host. We may almost think of it as a 

 machine for catching insects, a mechanical toy, clicking out its sharp 

 notes. 



But let us note this fact. Every ten years or so the swifts do not 

 appear about our house in the spring. Something has gone wrong on 

 their journey northward. Our chimney will be empty this year; 

 there will be no dark bows and arrows dashing back and forth above 

 our roof, no quick pursuits and chattering in the evening. All sum- 

 mer something is lacking because there are no swifts to enliven the 

 season. We realize, now that they are gone, how we should miss their 



