INTRODUCTION, XXV 
their mutual attachment. When the young appear, a new 
source of care and pleasure opens to them, still strengthening 
the ties of affection; and the tender charge of rearing and 
defending their infant brood requires the joint attention of 
both parents. The warmth of first affection is thus succeeded 
by calm and steady attachment, which by degrees extends, 
without suffering any diminution, to the rising branches of the 
family. 
This conjugal union, in the rapacious tribe of birds, the 
Eagles and Hawks, as well as with the Ravens and Crows, con- 
tinues commonly through life. Among many other kinds it is 
also of long endurance, as we may perceive in our common 
Pewee and the Blue-bird, who year after year continue to fre- 
quent and build in the same cave, box, or hole in the decayed 
orchard tree. But, in general, this association of the sexes 
expires with the season, after it has completed the intentions 
of reproduction, in the preservation and rearing of the off- 
spring. The appearance even of sexual distinction often van- 
ishes in the autumn, when both the parents and their young 
are then seen in the same humble and oblivious dress. When 
they arrive again amongst us in the spring, the males in flocks, 
often by themselves, are clad anew in their nuptial livery; and 
with vigorous songs, after the cheerless silence in which they 
have passed the winter, they now seek out their mates, and 
warmly contest the right to their exclusive favor. 
With regard to food, birds have a more ample latitude than 
quadrupeds ; flesh, fish, amphibia, reptiles, insects, fruits, grain, 
seeds, roots, herbs, —in a word, whatever lives or vegetates. 
Nor are they very select in their choice, but often catch indif- 
ferently at what they can most easily obtain. Their sense of 
taste appears indeed much less acute than in quadrupeds ; for 
if we except such as are carnivorous, their tongue and palate 
are, in general, hard, and almost cartilaginous. Sight and scent 
can only direct them, though they possess the latter in an infe- 
rior degree. The greater number swallow without tasting ; and 
mastication, which constitutes the chief pleasure in eating, is 
entirely wanting to them. As their horny jaws are unprovided 
