Brewster on the Philadelphia Vireo. 
5 
in that near-sighted way peculiar to the tribe. Occasionally its 
search among the unfolding leaves is rewarded by the discovery of 
some luckless measuring-worm, which is swallowed with the same 
indifference that marks all the bird’s movements. You begin to 
feel that nothing can disturb the equanimity of the little philoso- 
pher, when it suddenly launches out into the sunshine, and, with an 
adroit turn, captures a flying insect invisible to human eyes. The 
next moment there is a dim impression of glancing wings among 
the trees, and it has vanished. There is little chance of finding it 
again, for its voice has as yet no place in the chorus that rises from 
the budding thickets around. 
But after the trees become dense with foliage, and the sense of 
early summer steals over the land, even the shy reserve of our 
recluse yields to the subtile influence, and he finds a tongue no less 
joyous than the rest. Indeed, after the breeding season has fairly 
begun, he is quite as indefatigable a singer as his Bed-eyed cousin. 
I have heard his cheerful voice all day long when a gloomy storm 
brooded over the dripping woods, and during the hottest June 
days he is rarely silent for any length of time, even at noontide. 
Nor does cold, blustering weather seem to affect his spirits. I re- 
member shooting one in a tall yellow birch when a high north wind 
was bending the stoutest trees like so many saplings. The branch 
to which the little singer clung was lashed about by the blasts, 
which flouted the leaves and swung the whole tree-top through the 
air ; yet he hardly paused a moment in his strain, though his voice 
was at times nearly drowned by the rushing wind. 
Contrary to what might be expected from the apparently close 
relationship of the two birds, the song of this species does not in 
the least resemble that of Vireo gilvus. ' It is, on the other hand, so 
nearly identical with that of V. olivaceus that the most critical 
ear will, in many cases, find great difficulty in distinguishing be- 
tween the two. The notes of philadelphicus are generally pitched 
a little higher in the scale, while many of the utterances are feebler, 
and the whole strain is a trifle more disconnected. But these dif- 
ferences are of a very subtile character, and, like most comparative 
ones, they are not to be depended upon unless the two species can 
be heard together. The Philadelphia Vireo has, however, one note 
which seems to be peculiarly its own, a very abrupt, double-sylla- 
bled utterance, with a rising inflection, which comes in with the 
general song at irregular but not infrequent intervals. I have also, 
