_Culicivora atricapilla_, LAWRENCE, Ann. N. Y. Lyc. V, Sept. 1851,
124 (not of SWAINSON). _Culicivora mexicana_, CASSIN, Illust. I,
1854, 164, pl. xxvii (not of BON.). _Polioptila melanura_,
LAWRENCE, Ann. N. Y. Lyc. VI, Dec. 1856, 168.—BAIRD, Birds N. Am.
1858, 382; Review, 68.—HEERMANN, P. R. R. R. vol. X (Williamson),
1859, 39.—COOPER, Birds Cal. 1, 37.
SP. CHAR. Above plumbeous-blue. Whole crown, to bill and eyes, with
tail, lustrous blue-black. Beneath pale bluish-gray, almost white on
chin and anal region; the flanks and crissum tinged with brown. Edge
of eyelids, and margin and tip of outer web of first and second
lateral tail-feathers, white. Female and young without the black of
the crown. Length, 4.15; wing, 1.85; tail, 2.10.
HAB. San Diego to Fort Yuma and Cape St. Lucas. Arizona, COUES.
Specimens of this species from Cape St. Lucas differ from those of San
Diego described in the P. R. R. Report (7,191) in having the whole of
the outer web of the outer tail-feather white, and in a rather larger
white tip. The colors beneath are a little less ashy, though not of a
pure white. The ash of the back is rather lighter and purer. The lores
are rather lighter. The first primary is a little larger and broader.
It is possible that the restriction of the white of the outer web of
the exterior tail-feather to the outer half only is an unusual
circumstance, as both Mr. Cassin and Mr. Lawrence, in their
descriptions, speak of the entire outer web being white,—the second
feather being of the former character. Under these circumstances there
will be little specific difference between the tails of _P. melanura_
and _plumbea_. The female birds will then be separated by the light
superciliary line and much shorter tarsi of _P. plumbea_,—the latter
measuring .63 instead of nearly .70 of an inch.
HABITS. This species was first noticed as belonging to the North
American fauna by Captain McCown, who obtained it near Ringgold
Barracks in 1850. It has since been noticed at Fort Yuma and at San
Diego, and obtained in greater abundance at Cape St. Lucas. It is also
found in Mexico. Dr. Cooper says that it is common all winter both at
San Diego and at Fort Mohave. It has been traced as far north as
latitude 30° in the Sierra Nevada. Its song he describes as a harsh
ditty of five parts, something like a wren’s song, with notes like
those of a swallow, and also closely resembling the song of _Vireo
belli_. Their scolding note is a faint mew, like that of a cat.
The habits of this species appear to be not unlike those of the
peculiar family to which it belongs. All its members are among our
smallest birds, are almost exclusively inhabitants of woods, and
resemble the _Reguli_ in their restless activity in pursuit of the
smallest insects on which they feed. This bird is described as
particularly active, quick in its movements, searching with great
activity for its food, and preferring low trees and bushes. At times
it will dart about in the air in pursuit of small insects.
Mr. John Xantus found these birds to be quite abundant at Cape St.
Lucas, and obtained several of their nests. They were generally built
among the interlacing tendrils of a wild vine (_Antigonon leptopus_),
and so closely interwoven with the smaller branches as to be
inseparable. The nests, like those of all this family, are structures
of great beauty and delicacy. They have a height and an external
diameter of about 2¼ inches. The cavity is 1½ inches wide at the rim,
and fully two inches deep. This great proportionate depth of the nest
seems to be characteristic of this genus. The external portion of this
nest is composed of a composite blending of various vegetable
materials, fine hempen fibres of plants, strips of delicate bark from
smaller shrubs, silken fragments of cocoons and downy cotton-like
substance, all very closely impacted and felted together, somewhat
after the manner of the Humming-Bird. The whole is very softly and
warmly lined with a beautifully interwoven and silky fabric composed
of the soft down of various plants.
The walls of the nest, though of the softest materials, are so thick
and so firmly impacted as to make it a structure remarkably firm and
secure against accidents.
The eggs, four in number, measure .55 of an inch in length by .45 in
breadth. They are of an oblong-oval shape, their ground-color is a
pale greenish-white sprinkled over the entire surface with fine
dottings of purple, reddish-brown, and black.