Acadia National Park

Description  ADULT Has mostly dark olive-brown upperparts, with indistinct pale eyering. Wings and tail are mostly blackish with faint pale wing bars; white feathers on side of rump sometimes overlap inner wing feathers at rest. Throat is white and color continues down center of breast to belly and undertail. Streaked dark olive-brown flanks look like an unbuttoned vest. JUVENILE Similar, but plumage, including wing bars, is warmer buff overall.

Dimensions  Length: 7 1/2" (19 cm)

Habitat  Widespread and still locally common summer visitor (mainly May-Aug) to boreal forests and damp, coniferous woodland. Has declined markedly in recent years. Forest loss and degradation here, and in South American winter quarters, are probably to blame.

Observation Tips  Easy to observe, but scarcer in recent years.

Range  Alaska, Mid-Atlantic, Southeast, Plains, Western Canada, New England, Northwest, Eastern Canada, California, Southwest, Florida, Rocky Mountains, Great Lakes, Texas

Voice  Utters a liquid quip-wee-ber or a rapid wip-wip-wip.

Discussion  Plump-bodied, rather dark-looking flycatcher. Often perches on exposed dead branches, adopting an upright posture. Flying insects caught in aerial forays. Bill is dark and relatively large, and tail is short. Sexes are similar.

Migration Info  This species' annual migration is the longest of any flycatcher that breeds in North America. The Olive-sided's winter habitat is primarily in the highlands of Panama and the northern Andes. Peak winter abundance is in the Andean portion of Colombia. Migrants generally bypass the Yucatan (although there are a few trans-Gulf migrants each year) and move through North America via the western forests. Olive-sided Flycatchers leave their winter territories in late March and are among the later arrivals in the southern states. The reason for this late arrival on breeding territories is probably this species' dependence on large flying insects, which are less numerous before the warmer spring weather.