_Motacilla sialis_, LINN. S. N. 1758, 187 (based on CATESBY, I, pl.
xlvii). _Sialia sialis_, BAIRD, Birds N. Am. 1858, 222; Rev.
62.—BOARDMAN, Pr. Bost. Soc. 1862, 124 (Calais, Me.; very
rare).—DRESSER, Ibis, 1865, 465 (Texas, winter).—SAMUELS, B. N.
Eng., 175. _Sialia wilsoni_, SWAINSON, Zoöl. Jour. III, 1827,
173.—CAB. Jour. 1858, 120.—GUNDLACH, Cab. Jour. 1861, 324;
Repertorio, 1865, 230.—JONES, Nat. Bermuda, 1859, 28, 66
(resident in Bermuda). _Sylvia sialis_, LATH.; _Ampelis sialis_,
NUTT.; _Erythraca wilsoni_, SW.
Figures: VIEILLOT, Ois. Am. Sept. II, pl. ci, cii, ciii.—WILS. I,
pl. iii.—AUD. Orn. Biog. II, pl. cxiii.—IB. B. A. II, pl.
cxxxiv.—DOUGHTY, Cab. I, pl. xii.
SP. CHAR. Entire upper parts, including wings and tail, continuous and
uniform azure-blue; the cheeks of a duller tint of the same. Beneath
reddish-brown; the abdomen, anal region, and under tail-coverts white.
Bill and feet black. Shafts of the quills and tail-feathers black.
Female with the blue lighter, and tinged with brown on the head and
back. Length, 6.75; wing, 4.00; tail, 2.90.
_Young._ Males of the year dull brown on head and back; and lesser
coverts streaked, except on head, with white. Throat and fore part of
breast streaked with white. Tertials edged with brown. Rest of
coloration somewhat like adult.
HAB. Eastern United States; west to Fort Laramie, Milk River; north to
Lake Winnipeg; resident in Bermuda; Cuba (rare), GUNDLACH.
A specimen from Guatemala (50,411 ♂, Van Patten) referrible to the
var. _azurea_ is undistinguishable in color from North American
examples; the wings and tail are longer, however, measuring
respectively 4.20 and 3.00.
[Illustration: _Sialia sialis._]
HABITS. The Bluebird is abundant throughout the eastern portion of
North America, breeding in nearly every part, from Georgia and
Louisiana to the Arctic regions, with only this exception, that near
the seaboard its migrations do not extend so far to the north as in
the interior. It is very rarely to be met with beyond the Penobscot,
although Professor Verrill mentions it as very common in the western
part of Maine. It is found throughout the year in the Bermudas, and
occasionally in Cuba. The Selkirk Settlement is the most northern
locality to which it has been traced. It is not known to occur farther
west than the highlands west of the Mississippi.
Through all the Eastern States the Bluebird is one of the most
familiar and welcome of the earliest visitors of spring, usually
making its appearance as early as the first of March. In mild seasons
they come in the latter part of February, long before there is any
apparent relaxation of the severity of winter. In 1857, in consequence
of the unusual mildness of the season, Bluebirds appeared in large
numbers as early as the 15th of February, and remained apparently
without suffering any inconvenience, although the weather subsequently
became quite severe. In 1869 their first appearance was observed as
early as the 28th of January, the earliest period of which I can find
any record.
In the Middle States, with every mild winter’s day, the Bluebirds come
out from their retreats, and again disappear on the return of severer
weather. Later in the season, or early in March, they return and make
a permanent stay.
When well treated, as the Bluebirds almost universally are, they
return year after year to the same box, coming always in pairs. The
marked attentions of the male bird are very striking, and have been
noticed by all our writers. He is very jealous of a rival, driving off
every intruder of his own species who ventures upon the domain he
calls his own. Occasionally the pair suffer great annoyance from
vexatious interferences with their domestic arrangements by the house
wren, who unceremoniously enters their homestead, despoils it of its
carefully selected materials, and departs. At other times the wren
will take possession of the premises and barricade the entrance,
making the return of its rightful owners impossible.
The song of the Bluebirds is a low warble, soft and agreeable,
repeated with great constancy and earnestness, and prolonged until
quite late in the season. Just before their departure, late in
October, the sprightliness of their song nearly ceases, and only a few
plaintive notes are heard instead.
The food of the Bluebird consists principally of the smaller
coleopterous insects, also of the larvæ of the smaller lepidoptera. In
the early spring they are very busy turning over the dry leaves,
examining the trunks and branches of trees, or ransacking posts and
fences for the hiding-places of their prey. In the fall their food
partakes more of a vegetable character.
The Bluebird selects as a suitable place for its nest a hollow in the
decayed trunk of a tree, or boxes prepared for its use. Their early
arrival enables them to select their own site. The nest is loosely
constructed of soft materials, such as fine grasses, sedges, leaves,
hair, feathers, etc. These are rarely so well woven together as to
bear removal. The eggs are usually five and sometimes six in number.
There are usually three broods in a season. Before the first brood are
able to provide for themselves, the female repairs her nest and
commences incubation for a second family. The young birds are,
however, by no means left to shift for themselves. The male bird now
shows himself as devoted a parent as in the earlier spring he had
proved himself an attentive mate. He watches over the brood even after
the second family appears and claims his attention. We often find him
dividing his cares in the latter part of the season with two broods,
and at the same time supplying his mate with food, and occasionally
taking her place on the nest.
The eggs of the Bluebird are of a uniform pale blue, measuring about
.81 of an inch in length by .62 in breadth.
In Guatemala is found a local race differing in its lighter under
colors and in the greenish tinting of its blue (_S. azurea_). The _S.
sialis_ is also found in the more open districts of the elevated
regions where it is numerous. It is there known as “_El azulejo_.”
Sialia mexicana, SWAINS.