The notes of the Warbling Vireo have been described by the words, "Brigadier, Brigadier, Bridget." They are few, simple, and melodious, and being often repeated, they form a very important part of the sylvan music of cultivated and thickly-settled places. It is difficult to obtain sight of this little warbler while he is singing, on account of his small size, the olive color of his plumage, and his habit of perching among the dense foliage of the trees. The Red-eyed Vireo is more generally known by his note, because he is particularly vocal during the heat of the long summer-days, when other birds are comparatively silent. The modulation of his notes is similar to that of the common Robin, but his tones are sharper, and he sings in a very desultory manner, leaving off very frequently in the middle of a strain to seize a moth or a beetle. Singing, while he is engaged in song, never seems to be his sole employment. This is the little bird that warbles for us late in the summer, after almost all other birds have become silent, uttering his moderate notes, as if for his own amusement, during all the heat of the day, from the trees by the roadsides and in our inclosures. We might then suppose him to be repeating very moderately the words, "Do you hear me? Do you see me?" with the rising inflection of the voice, and with a pause after each sentence, as if he waited for an answer. As soon as the cherry-tree is in blossom, and when the oak and the maple are beginning to unfold their plaited leaves, the loud and mellow notes of the Golden Robin (_Icterus Baltimore_) are heard for the first time in the year. I have never known the birds of this species to arrive before this date, and they seem to be governed by the supply of their insect food, which probably becomes abundant simultaneously with the flowering of the orchards. These birds may from that time be observed diligently hunting among the branches and foliage of the trees, and they appear to make a particular examination of the blossoms, from which they obtain a great variety of flies and beetles that are lodged in them. While thus employed, the bird frequently utters his brief, but loud and melodious notes; but he sings, like the Vireo, only while attending to the wants of life. Almost all remarkable singing-birds, when warbling, give themselves up entirely to song, and pay no regard to other demands upon their time until they have concluded. But the Golden Robin never relaxes from his industry, nor remains stationed upon the branch of a tree for the sole purpose of singing. He sings, like an industrious maid-of-all-work, only while employed in the ordinary concerns of life.