Euphagus carolinus
Order Passeriformes
Family Icteridae
Subfamily Agelaiinae
♂ Adult male in spring.— Entire plumage glossy bluish-black; eye pale yellow or white.
♀ Adult female in spring.— Slate-gray; eye as in male.
Adult in autumn.— Feathers of head, neck, and back tipped with rusty-brown; under parts buffy.
Nest, in trees, bulky.
Eggs, bluish-green, olive, or brownish, speckled and spotted with brown.
The Rusty Blackbird (rusty only in the autumn) is a common migrant through New York and New England, from the middle of March to the first week of May, and again from the end of September through October, or in the vicinity of New York city until December. It breeds to some extent in the northern and extreme eastern counties of Maine. The Rusty Blackbird is as fond of wet places as the Red-wing; it is generally found in small flocks near marshes and at the borders of water-courses. Like the Redwing, it visits to some extent the dry hillsides, particularly in the fall.
When seen at a distance, and in flight, it is almost impossible to distinguish between this bird and the Red-wing, unless the split or squeaking whistle of the Rusty is heard. This is its song, corresponding to the congaree of the Redwing; it is heard both in spring and fall. The species also has a chuck practically indistinguishable from that of the Red-wing, and has the same trick of jerking its tail upward when perched. When seen near to, the absence of any mark on the shoulder should distinguish the Rusty; the tail, though slightly rounded, can hardly be confused with the long, extremely rounded tail of the Bronzed Grackle. The surest mark by which the Rusty may be distinguished from the Red-wing, if one can get near enough, is the white eye. The female might be confused with the female Cowbird, but in most cases the latter would not occur in the wet places affected by the former; moreover the Cowbird’s bill is shorter. The female Red-wing is heavily streaked. A Rusty Blackbird in autumn might be mistaken for a male Cowbird, but the rusty is much more widely distributed in the former, extending well down the back, and the bill is longer and sharper.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)