4.*]4 NORTH AMKPJCAN BIRDS. 



Tlu'V are not, Imwover, to \ye ro^jjarded as nocturnal, as they are only known 

 to do this during; u hrief jK-riod. 



The nest of tins species is a very peculiar and remarkable structure. It 

 is composed of small twi^s of nearly uniform size, wrouj^ht and interwoven 

 into a neat semicircular basket. In selectin;^ the twi^s with wiiieh they are 

 to construct their nests, the Swifts break from the tree the ends of livin<; 

 branches, which they j-ather with fjreat skill and adroitness while on the 

 wim,'. Sweeping' upon the covete<l twig somewhat as a Hawk rushes on its 

 ]»rt'y, it divides it at the desired place, and beai-s it off to its nest. This is 

 a well-attested fiict, fanuliar to all who have ever watched these birds in 

 the earlv mornint' as thev are at work constructing their nests. 



Kach one of these twi<'s is strou'dv fastened to its fellows by an adhesive 

 saliva secreted by the bird, and by the same cement the whole structure is 

 made to adhere to the side of the chimney in which it is built. This saliva, 

 as it dries, hardens into a tou^h j;lue-like substance, as firm even a.s the 

 twi^^s it unites. In separating nests from the sides of chimneys, T have 

 known portions of the brick to which it was fastened part sooner than the 

 cement. When moistened, however, by long-continued rains, the weight of 

 their contents will sometimes cause these nests to j)art, and the whole is 

 precipitated to the bottom. The young birds cling very tenaciously to the 

 sides of the chinmeys with their bills and claws. They not only are often 

 able, in these accidents, to save themselves from falling, but even at a 

 very early age can cling to the sides of the chimney and work their way 

 to the top. They always leave their nest and climb to the upper part of 

 the chimney several tlays before they can fly, and are there fed by their 

 parents. 



Occasionally the young birds fall to the bottom of the chimney, out of the 

 reach or notice of their parents. I have never been able to induce them to 

 take any food, although they keep uttering pitiful cries of hunger. In such 

 cases the young birds placed on the roof near their native chimney soon 

 manage to climb to its base, and there receive the aid of the old birds. 



Their eggs are four in number, somewhat elliptical in form, though some- 

 what less obtuse at one end than the other. They are of a pure white 

 color, and are never spotted. They vary but little in size or shape, and 

 measure from .7o to .81 of an inch in length, and from .50 to .55 in breadth. 



In Xew England the Chimney Sw^allow raises but one brood in a season. 

 In Pennsylvania it is said to have two. 



