THE BLUE YELLOW-BACKED WARBLER. 203 
PARULA, Bonaparte. 
Parula, BONAPARTE, Geog. and Comp. List, 1838. (Type Parus Americanus.) 
In the species of this genus, the bill is conical and acute; the culmen very gently 
curved from the base; the commissure slightly concave, the notch when visible is 
further from the tip than in Dendroica, but usually is either obsolete or entirely 
wanting; bristles very short; the tarsi are longer than the middle toe; the tail is 
nearly even, and considerably shorter than the wing. 
PARULA AMERICANA, — Bonaparte. 
The Blue Yellow-backed Warbler. 
Parus Americanus, Linneus. Syst. Nat., I. (1758) 190. 
Sylvia Americana. Aud. Orn. Biog., I. (1882) 78. 
Parula Americana, Bonaparte. List (1838). b., Consp. (1850), 310. 
Sylvia pusilla, Wilson. Am. Orn., IV. (1811) 17. 
DESCRIPTION. 
Above blue, the middle of the back with a patch of yellowish-green; beneata 
yellow anteriorly, white behind; a reddish-brown tinge across the breast; lores and 
space round the eye dusky; a small white spot on either eyelid; sides of head 
and neck like the crown; two conspicuous white bands on the wings; outer two tail 
feathers with a conspicuous spot of white; female similar, with less brown on the 
breast. 
Length, four and seventy-five one-hundredths inches; wing, two and thirty-four 
one-hundredths inches; tail, one and ninety one-hundredths inch. 
Hab. — Eastern North America to the Missouri, south to Guatemala. 
This species, I am inclined to think, is rather common 
in all of New England; and it undoubtedly breeds more 
or less abundantly in each of these States. It arrives from 
the South about the middle of May, sometimes a little ear- 
lier. The birds, on their arrival, seem to be mated; for 
they are almost always seen in pairs, often two males with 
one female. Their habits are very similar to those of the 
Titmice, and they are equally at home in the high foliage of 
trees and in the low thickets and shrubbery. When travel- 
ling through the trees, they run nimbly both across and 
along the branches, sometimes hanging head downwards, 
sometimes fluttering at the extremity of a small twig: they 
are very nervous and active, and are almost continually 
employed in catching caterpillars and insects, of which 
their food consists. While thus engaged, they emit, occa- 
