Genus—Sialia Species—Mexicana
Subspecies—Bairdi
Lower Figures—BLUEBIRDS
Order—Passeres Family—Turdidæ
Genus—Sialia Species—Sialis
“When the breeding season is over, the birds travel sometimes in family groups and sometimes in large flocks, moving southward little by little, according to season and food supply, some journeying as far as Mexico, others lingering through the middle and southern states. The Bluebirds that live in our orchards in summer are very unlikely to be those that we see in the same place in winter days. Next to breeding impulse, the migrating instinct seems to be the strongest factor in bird-life. When the life of the home is over, Nature whispers, ‘To wing, up and on!’ So a few of the Bluebirds who have nested in Massachusetts may be those who linger in New Jersey, while those whose breeding-haunts were in Nova Scotia drift downward to fill their places in Massachusetts. But the great mass of even those birds we call winter residents go to the more southern parts of their range every winter; those who do not being but a handful in comparison.
“Before more than the first notes of the spring have sounded in the distance, Bluebirds are to be seen by twos and threes about the edge of old orchards along open roads, where the skirting trees have crumbled or decaying knot-holes have left tempting nooks for the tree-trunk birds, with which the Bluebird may be classed. For, though he takes kindly to a bird-box, or a convenient hole in fence-post, telegraph pole, or outbuilding, a tree hole must have been his first home, and consequently he has a strong feeling in its favour.
“As with many other species of migrant birds, the male is the first to arrive; and he does not seem to be particularly interested in house-hunting until the arrival of the female, when the courtship begins without delay, and the delicate purling song, with the refrain, ‘Dear, dear, think of it, think of it,’ and the low two-syllabled answer of the female is heard in every orchard. The building of the nest is not an important function,—merely the gathering of a few wisps and straws, with some chance feathers for lining. It seems to be shared by both parents, as are the duties of hatching, and feeding the young. The eggs vary in number, six being the maximum, and they are not especially attractive, being of so pale a blue that it is better to call them bluish white. Two broods are usually raised each year, though three are said to be not uncommon; for Bluebirds are active during a long season, and, while the first nest is made before the middle of April, last year a brood left the box over my rose arbour September 12, though I do not know whether this was a belated or a prolonged family arrangement.
“As parents the Bluebirds are tireless, both in supplying the nest with insect food and attending to its sanitation; the wastage being taken away and dropped at a distance from the nest at almost unbelievably short intervals, proving the wonderful rapidity of digestion and the immense amount of labour required to supply the mill inside the little speckled throats with grist.
“The young Bluebirds are spotted thickly on throat and back, after the manner of the throat of their cousin, the Robin; or rather, the back feathers are spotted, the breast-feathers having dusky edges, giving a speckled effect.