BIRDS OF THE UNITED STATES. 
79 
But ill I0W61 latitudss, ths first two or tliroo wGoks uftGr tho urrivul 
of these birds, is spent in the procurement of food. The good which is 
then accomplished, cannot be fully appreciated, and is of such immense 
value as to gain for the species the high position which it occupies in 
the affections of mankind. 
During the whole of this time, we have seen nothing that would 
appeal to indicate that courtship is indulged in. Perhajis this necessary 
business of bird-life is practised in mid-air, while the sexes are skimming 
through the swaying fluid, or circling in joyous company high overhead. 
May not the pleasing, lively succession of twitterings which drop earth- 
ward, when these lovely creatures are careering towards the dome of 
heaven, be the love-songs which the males are pouring into the ears of 
listening females? To3e fully appreciated, they should be heard during 
these exciting aerial movements. When perching, the birds seem less 
animated; consequently, the music is slower, hut none the less agreeable. 
Whether this business is in vogue or not among these birds, matters 
little, so long as the important duty which has brought them hither is ac- 
comjilished. That this is the case, is indisputable, as the sexes are known 
to separate from the flocks, and repair to accustomed haunts to build. 
The period of nesting varies somewhat according to latitude and the 
conditions of the weather. In the West, nests have been found with eo-o-s 
as early as the thirtieth of April, but this was in the vicinity of San 
Fi an cisco. In semi-tropical regions, it is reasonable to look for an early 
assumption of matrimonial relations. But in the generality of instances, 
outside of our warm Southern latitudes, the birds commence to build their 
domiciles fiom the fifteenth to the last of May, and, in some cases, even 
running into the first week of the month that follows. 
In the construction of a home, which is usually the work of six days, 
the builders apply themselves with persevering assiduity, only stopping 
from their labors, for brief spells of time, in order to rest, or to procure 
the essential articles of food. 
