12 cm (5") Common; more so in the west than in the east. Moist woodlands, bogs, especially thickets of willows and streamside undergrowth.
A small warbler with a beady black eye. Olive above. Yellow below.Long tail is black above and below and often cocked.
Male: distinct round black cap.
Female and Immature: lacks distinct black cap. Has no white in tail like similar female Hooded warbler.
Song: chatter.