One of the most appropriately named warblers (it is rarely found away from pines), the pine has a drab plumage that makes identification challenging away from breeding areas. It is the only wood-warbler known to regularly feed on seeds, mainly in fall and winter. Between April and June, it builds a nest high in a pine on a horizontal limb, often at the end of a branch, and lays 3 to 5 eggs. Polytypic (4 ssp.; pinus and florida, not field identifiable, in North America). Length 5.3".
Adult male: olive green upperparts. Yellow throat, breast, and belly, extending to rear of olive cheeks; white lower belly and undertail coverts. Dull olive to blackish indistinct streaks on sides of breast. Indistinct broken yellow eye ring and supercilium. Two white wing bars; large white tail spots on outer tail feathers. Adult female: similar to male, but paler yellow, with streaks on sides, an eye ring, very indistinct supercilium, smaller tail spots. Immature: duller than adult; female often quite brownish and buffy with little or no olive or yellow.
The yellow-throated vireo is larger and more sluggish and has a thicker hooked bill, conspicuous yellow spectacles, and unstreaked underparts. In fall, bay-breasteds and blackpolls are similar. The pine does not have streaking on upperparts, yellow on throat extending behind auriculars, longer tail extending well beyond undertail coverts, or shorter primary projection beyond tertials, and its wing bars contrast less with wings.
Call: a slurred tsup, similar to the yellow-throated’s and the Grace’s. Flight call: a slightly buzzy zeet. Song: a musical trill, most similar to the chipping sparrow’s or the dark-eyed junco’s but usually softer, more musical, and shorter, varying in speed. Occasionally 2-parted songs, with the second part being faster and higher pitched. Also similar to the worm-eating’s and orange-crowned’s.
Status and Distribution
Common, occurring in North America year-round, with northern populations migratory (2 sedentary ssp. resident in Caribbean). Breeding: a broad range of pine habitats. Migration: one of the earliest spring migrant warblers in many areas: begins northward movement in late February, arriving by early April in southern Great Lakes, mid-April in New England, and late April–early May in northernmost breeding areas. One of the latest fall migrant warblers: departs northernmost breeding areas as early as late August but peaks late September–mid-October, rarely into November and with stragglers into December and January. Winter: pine forests in southeastern United States, rarely to northern Caribbean. Sometimes forages on ground in fields and pastures near forest edges. Vagrant: rare, mainly in fall, in Atlantic Canada. Rare or casual in northern Great Plains and Prairie Provinces. Very rare in West, with most records (60) from coastal southern California in fall and winter. Casual in southern Caribbean in winter, accidental in fall in Greenland.
Stable or increasing.
—From the National Geographic book Complete Birds of North America, 2006