The song which may be written pit, pit-a-ta-chee-whēēr, does not suggest a vireo at all. Remember that this bird will be found among low, thick bushes.
BLUE-HEADED VIREO
Lanivireo solitarius solitarius (Wilson)
Description.—Size of the Red-eye, but upper part of head rich blue-gray, with a prominent line in front of and around eye, white; wings with two noticeable bars; sides yellow, irregularly washed with olive-green; chin, throat, breast, and belly, white. Length: A little over 5½ inches.
Range in Pennsylvania.—A fairly common migrant and summer resident. It is the first of the vireos to arrive in spring, appearing in mid- or latter April and remaining until October. It nests only at high altitudes in the mountains or in the northern counties.
Nest.—A neat and beautifully built pensile cup, swung on a horizontal hemlock, witch hazel, or alder bough, usually deep in the woodlands. Eggs: 3 or 4, white, with a few small black spots.
The song of this handsome vireo is rich and beautiful—easily the most musical of all our vireo songs. It is to be heard chiefly in the depths of the coniferous woodlands. Unusually elaborate and prolonged songs are sometimes given in the spring. Remember the prominent white eye-ring of this species.
BLACK AND WHITE WARBLER
Mniotilta varia (Linnæus)
Other Names.—Black and White Creeper; Black and White Creeping Warbler.
Description.—Black and white all over, the colors about evenly balanced, giving the bird in the field a streaked appearance, noticeable particularly in the male. Since no other warbler is thus streaked with black and white all over, it is thought that this description is sufficient. Females and young: Duller, the young with buffy washings on sides. Length: 5⅓ inches.
Range in Pennsylvania.—A migrant and summer resident from late April and early May to September. It is rather local as a summer resident though it may occur in any suitable woodland.
Nest.—A cup of rootlets and fine grasses placed on the ground at the base of a sapling or a fallen bough or log, usually in rather open woodland. Eggs: 4 or 5, white, with a neat wreath of fine red-brown spots about the larger end.
Black and White Warbler
This bird is nearly always seen creeping about the trunks and larger branches of trees, and its boldly streaked plumage is unmistakable. Its song, which has been written wee-see, wee-see, wee-see, wee-see, is wiry and unmusical, and the untrained ear will probably not catch it. Look for this bird in any woodland, particularly where there are deciduous trees.
The southern Prothonotary Warbler (Protonotaria citrea) is rarely recorded in the southern counties. This species has blue-gray wings and tail, no wing-bars, and the head and breast are rich orange-yellow. Records are desirable.