302 THE BIRDS OF MAINE 



the disadvantages prevailing, but it was between twenty-nine 

 and thirty-one days after hatching before they finally left the 

 nest, being seen by me on the thirty-first day on the limb of a 

 near by elm from which they essayed short flights, and as I 

 had not visited the locality for two days they might have left 

 the nest any time between the periods mentioned. 



Both birds aided in incubating and feeding the young. 

 The act of mating was accomplished on the wing, the male 

 and female flying in a short circle, the male to the rear, and 

 the mating being accomplished very quickly. Both while on 

 the wing and in the chimney the species utters its peculiar well 

 known twittering call much like "switter-switter-switter-cheee." 

 In some chimneys dozens of pairs nest while in others only one 

 or two will be found. 



I have found them nesting in barns in the country districts, 

 and in old logging camps in the woods, making similar nests 

 which are placed against the walls of the buildings. There is 

 no doubt but that some still nest in trees as I have seen them 

 entering large, hollow, inaccessible trees in the northern woods. 

 The eggs are pure white, often stained with soot, and three 

 to five are laid at dates from as early as June 15 to July 10. 

 A nest, taken eleven feet down in a chimney on July 2, 1884, 

 contained four fresh eggs. Three of these measure 0.75 x 0.52, 

 0.73x0.51,0.74x0.50. The fourth egg somehow was lost 

 and has not since been located, doubtless being " nipped " by 

 somebody to whom I was showing my collections. It is indeed 

 strange but true that specimens sometimes disappear under con- 

 ditions which would indicate the cause of such disappearance 

 to be a source which would be supposed unimpeachable, and to 

 whom a bird's egg would be of no use, though in cases where 

 handsome mineral specimens have disappeared after an influx 

 of fair curiosity seekers the temptation can be better understood. 

 The food of the Chimney Swallow consists of almost any of 

 the smaller insects which fill the air of a summer's day, mos- 

 quitoes, midges, flies, small moths, winged ants and similar 

 material, so that we can call the Swift very beneficial. 



