The Indigo Bird is an active and lively little fellow, possesses much elegance in his shape, and also a certain degree of firmness in his make, which renders him equally a favourite with the Painted Finch, although he does not possess the variegated plumage of the latter. When the male of the species now before you is in full plumage, the richness of his apparel cannot fail to attract and please the eye of any observer. It is highly glossy, and changes from the brightest azure to green, when placed in a strong light. It requires three years to attain this perfect state. The female continues in the same very humble vesture which nature first accorded to her. The males, in the first spring, and not unfrequently during the first autumn, are mottled with dull light blue, interspersed among the original deep buff of their earlier stage. The blue increases in extent, and acquires a deeper tint, as the age of the bird advances. I have often seen males two years old which were still much inferior in the beauty of their plumage to those which had passed through three springs. Should the birds be caught when in full plumage, they gradually lose their brilliant tints, which at length become extremely dull. A similar alteration is observed to take place in Painted Finches which have been kept in cages for a certain period, as well as in the Baltimore and Orchard Orioles, and in the Bulfinch, Chaffinch, and other European birds.
The nest of the Indigo Bird is usually fixed amongst the rankest stalks of weeds or grass, now and then amongst the stems of a briar, or even in a small hollow in a decayed tree. In all cases its composition is the same; but when amongst grass, clover, or briars, it is attached to two or three of the stalks by its sides. It is formed of coarse grasses, hemp stalks, and flax, and is lined with slender grasses. The female lays from four to six eggs, which are blue, with a spot or two of purple at the larger end.
Towards fall, the young congregate into loose flocks or parties of eight or ten individuals, and proceed southward. I think their migration, at both periods of the year, is performed during night. Two broods are generally raised in a season. The food of the Indigo Bird consists of small seeds of various kinds, as well as insects, some of which it occasionally pursues on wing with great vigour. They are fond of basking and rolling themselves in the roads, from which they gather small particles of sand or gravel. I have frequently seen live birds of this species offered for sale in Europe.
I have represented an adult female, two young males of the first and second year, in autumn, and a male in the full beauty of its plumage.
