The nest of the Red-eyed Vireo is small, and extremely neat. It is generally suspended, at a moderate height, from the slender twigs forming the fork at the end of a branch. I have found some situated so low that I could easily look into them, while others were hung thirty feet over head. Dog-wood trees seem to be preferred by them, although I have found the nests on oaks, beeches, and sugar-maples, as well as on tall grasses. The male bird frequently leads you to the discovery of the nest, by its great anxiety about the safety of its mate. The outer parts are firmly attached to the twigs, the fibres being warped around them in various directions. The materials are usually the bark of the grape-vine, the silk of large cocoons, some lichens, particles of hornets' or wasps' nests, and decayed worm-eaten leaves. The lining, which is beautifully disposed, consists of fibrous roots, grasses, and now and then the hair of various quadrupeds, especially the grey squirrel and racoon. The nest, however, differs greatly in different latitudes; for, in the Middle States, they often use the leaves of the pine, cedar, and hemlock, which they glue together apparently with their saliva. The eggs are from four to six, pure white, sparingly spotted at the larger end with reddish-brown or blackish dots. They are laid in Pennsylvania about the first of June, and later in more northern parts.
The eyes of the Young are of an umber colour, and do not become red until the following spring. Those of some shot in the Floridas in January, had not changed their colour. In February I shot two, each of which had a red and a brown eye.
This species, as well as the White-eyed Vireo, is often called to nurse the young of the Cow Bird, which deposits its egg in the nests of either species, assured that it will be properly treated. No difference exists in the plumage, or even size of the sexes.
Wilson, who was a most excellent observer, was quite correct, as well as Dr Barton of Philadelphia, in alluding to another species of Vireo, which, although nearly allied to this, is quite distinct. It is smaller, has brown eyes at all times of its life, sings sweetly, lives in low thickets, and builds a pensile nest. You will see its figure in my fourth volume of Illustrations, when I hope to be able to give you a good account of its habits.
Vireo olivaceus, Ch. Bonaparte, Synops. of Birds of the United States, p. 71.
Red-eyed Flycatcher, Muscicapa olivacea, Wils. Amer. Ornith. vol. ii. p. 55. pl. 12. fig. 3.—Nuttall, Manual, p. 312.
Adult Male. Plate CL.
Bill of moderate length, strong, depressed at the base, compressed towards the end, somewhat ascending. Upper mandible with the dorsal line slightly convex, the sides convex, the edges sharp and notched towards the end, the tip acute and suddenly deflected; lower mandible with the dorsal line also slightly convex, the back rounded, the edges sharp and inflected, the tip acute. Nostrils basal, lateral, oblong. Head rather large, neck short, body rather robust. Feet of ordinary length; tarsus compressed, anteriorly scutellate, sharp behind; toes slender, free; claws arched, compressed, acute.
Plumage soft and blended. Wings rather long, the second and third primaries longest; tail of ordinary length, slightly emarginate. Bristles at the base of the bill short.
Bill brown above, pale bluish-grey beneath. Iris red. Feet bluish-grey. The general colour of the plumage above is light yellowish-olive, the crown of the head deep-grey, bordered on each side by a line of blackish, below which is a line of greyish-white passing from the nostril over the eye. Quills dusky, olivaceous on the outer margin, white on the inner. Tail wood-brown. The lower parts are white, the breast and sides tinged with pale yellow.