800 
INSECTIVOROUS BIRDS. 
tropical are still known to migrate to different distances 
on either side the equator, so essential and necessary is 
this wandering habit to almost all the feathered tribe. 
The Icteria arrives in Pennsylvania about the first 
week in May, and does not appear to proceed further 
north and east than the states of New York or Connecti- 
cut. In the distant interior, however, near the Rocky 
mountains, towards the sources of the Arkansa, this bird 
was observed by Mr. Say. It retires to the south about 
the middle of August, or as soon as the only brood it 
raises are fitted to undertake their distant journey. 
The males, as in many other migrating birds, who 
are not continually paired, arrive several days before the 
females. As soon as our bird has chosen his retreat, 
which is commonly in some thorny or viny thicket, 
where he can obtain concealment, he becomes jealous of 
his assumed rights, and resents the least intrusion, scold- 
ing all who approach in a variety of odd and uncouth 
tones, very difficult to describe or imitate, except by a 
whistling, in which case the bird may be made to ap- 
proach, but seldom within sight. His responses on such 
occasions are constant and rapid, expressive of anger and 
anxiety ; and still unseen, his voice shifts from place to 
place amidst the thicket, like the haunting of a fairy. 
Some of these notes resemble the whistling of the wings 
of a flying duck, at first loud and rapid, then sinking till 
they seem to end in single notes. A succession of other 
tones are now heard, some like the barking of young 
puppies, with a variety of hollow, guttural, uncommon 
sounds, frequently repeated, and terminated occasionally 
by something like the mewing of a cat, but hoarser ; a 
tone, to which all our Vireos, particularly the young, 
have frequent recurrence. All these notes are uttered 
with vehemence, and with such strange and various 
