Vireo solitarius
Order Passeriformes
Family Vireonidae
Other names: Solitary Vireo
Adult.— Top and sides of head dark slate-gray; line from bill to and around eye white; back gray, with a greenish-yellow tinge in strong light; wing-bars white; throat and breast white; sides of breast dark gray; sides of belly greenish-yellow.
Nest, a cup hung from a fork in a horizontal branch.
Eggs, white, sparsely spotted with brown at the larger end.
The Solitary Vireo is confined in summer to the Canadian and the sub-Canadian areas, but is a common migrant through the rest of New York and New England, passing north in the latter part of April and early in May, and returning late in September and early in October. As a migrant it frequents almost any piece of woodland, often coming into orchards and about houses. It breeds in deep, cool woods, either evergreen or deciduous, preferring possibly the former. It is much less common than the Red-eye, and its voice is louder and richer, so that as one passes along a woodland road, the Solitary Vireos inhabiting the region are easily noted, and are found to be separated by far greater intervals than the Red-eyes. The song resembles that of the Red-eye in form, but it has a sweeter, more appealing tone. Certain passages are characteristic; one is a “double note,” that is a phrase repeated quickly in a lower key; another resembles the syllables to-wee’-choo, the singer sliding from a high to a low note. Sometimes the singer has a fit of ecstasy in which he runs his phrases, ordinarily separated by considerable intervals, rapidly together, and follows them by sweet twittering. The song is not infrequently heard in the autumn, when the bird is migrating south. The alarm-note is an unmusical chatter, similar to that of the Yellow-throated Vireo.
The white ring around the eye of the Solitary Vireo and the white line from the eye to the bill are excellent fieldmarks.
Hoffmann – A Guide to the Birds of New England and Eastern New York (1904)