_Motacilla cærulea_, LINN. Syst. Nat. I, 1766, 337 (based on
_Motacilla parva cærulea_, EDW. tab. 302). _Culicivora cærulea_,
CAB. Jour. 1855, 471 (Cuba).—GUNDLACH, Repert. 1865, 231.
_Polioptila cærulea_, SCLATER, P. Z. S. 1855, 11.—BAIRD, Birds N.
Am. 1858, 380.—IB. Rev. 74.—DRESSER, Ibis, 1865, 231.—COOPER,
Birds Cal. 1, 35. _Motacilla cana_, GM. S. N. I, 1788, 973. _?
Culicivora mexicana_, BON. Consp. 1850, 316 (not of CASSIN),
female. _Polioptila mexicana_, SCLATER, P. Z. S. 1859, 363, 373.
Figures: VIEILL. Ois. II, pl. lxxxviii.—WILSON, Am. Orn. II, pl.
xviii, fig. 3.—AUD. Orn. Biog. I, pl. lxxxiv; IB. Birds Am. I,
pl. lxx.
SP. CHAR. Above grayish-blue, gradually becoming bright blue on the
crown. A narrow frontal band of black extending backwards over the
eye. Under parts and lores bluish-white tinged with lead-color on the
sides. First and second tail-feathers white except at the extreme
base, which is black, the color extending obliquely forward on the
inner web; third and fourth black, with white tip, very slight on the
latter; fifth and sixth entirely black. Upper tail-coverts
blackish-plumbeous. Quills edged externally with pale bluish-gray,
which is much broader and nearly white on the tertials. Female without
any black on the head. Length, 4.30; wing, 2.15; tail, 2.25. (Skin.)
HAB. Middle region of United States, from Atlantic to Pacific, and
south to Guatemala; Cape St. Lucas. Cuba, GUNDLACH and BRYANT.
Bahamas, BRYANT.
HABITS. The Blue-gray Flycatcher is a common species from the Atlantic
to the Pacific coast, although not met with in the New England States.
It is less abundant on the coast than at a distance from it, and has a
more northern range in the interior, being met with in Northern Ohio,
Michigan, and the British Provinces. Specimens occur in the
Smithsonian Institution collection from New York to Mexico and
Guatemala, and from Washington Territory to California.
They appear in Pennsylvania early in May, and remain there until the
last of September. They are observed in Florida and Georgia early in
March, but are not known to winter in that latitude. All the specimens
in the Smithsonian collection were obtained between April and October,
except one from Southern California, which was taken in December.
[Illustration: _Polioptila cærulea._]
Near Washington, Dr. Coues states the Blue-gray Gnatcatcher to be a
summer resident, arriving during the first week of April, and
remaining until the latter part of September, during which time they
are very abundant. They are said to breed in high open woods, and, on
their first arrival, to frequent tall trees on the sides of streams
and in orchards.
In California and Arizona this species occurs, but is, to some extent,
replaced by a smaller species, peculiarly western, _P. melanura_.
There they seem to keep more about low bushes, hunting minute insects
in small companies or in pairs, and their habits are hardly
distinguishable from those of Warblers in most respects.
The food of this species is chiefly small winged insects and their
larvæ. It is an expert insect-catcher, taking its prey on the wing
with great celerity. All its movements are very rapid, the bird
seeming to be constantly in motion as if ever in quest of insects,
moving from one part of the tree to the other, but generally
preferring the upper branches.
Nuttall and Audubon, copying Wilson, speak of the nest of this
Gnatcatcher as a very frail receptacle for its eggs, and as hardly
strong enough to bear the weight of the parent bird. This, however,
all my observations attest to be not the fact. The nest is, on the
contrary, very elaborately and carefully constructed; large for the
size of the bird, remarkably deep, and with thick, warm walls composed
of soft and downy materials, but abundantly strong for its builder,
who is one of our smallest birds both in size and in weight. Like the
nests of the Wood Pewee and the Humming-Bird, they are models of
architectural beauty and ingenious design. With walls made of a soft
felted material, they are deep and purse-like. They are not pensile,
but are woven to small upright twigs, usually near the tree-top, and
sway with each breeze, but the depth of the cavity and its small
diameter prevent the eggs from rolling out. Externally the nest is
covered with a beautiful periphery of gray lichens, assimilating it to
the bark of the deciduous trees in which it is constructed.
Occasionally these nests have been found at the height of ten feet
from the ground, but they are more frequently built at a much greater
elevation, even to the height of fifty feet or more. They are made in
the shape of a truncated cone, three inches in diameter at the base
and but two at the top, and three and a half inches in height. The
diameter of the opening is an inch and a half. In Northern Georgia
they nest about the middle of May, and are so abundant that the late
Dr. Gerhardt would often find not less than five in a single day, and
very rarely were any of them less than sixty feet from the ground. Dr.
Gerhardt, who was an accurate and careful observer, speaks of these as
the best built nests he had met with in this country, both in regard
to strength and its ingeniously contrived aperture, so narrowed at the
top that it is impossible for the eggs to roll out even in the
severest wind. They have two broods in the season in the Southern
States, one in April and again in July.
This Flycatcher lays usually five eggs. These are of a short oval
form, somewhat pointed at one end and rounded at the other, and
measure .56 of an inch in length by .44 in breadth. Their ground-color
is a greenish-white, marked and dotted with small blotches and spots
of varying and blending shades of reddish-brown, lilac, and slate.
Polioptila plumbea, BAIRD.