The Tennessee Warbler (Oreothlypis peregrina) is a New World warbler that breeds in eastern North America and winters in southern Central America and northern South America. The Tennessee Warbler is 11.5 centimeters (4.5 in) long, has a 19.69 centimeters (7.75 in) wingspan and weighs roughly 10 grams (0.35 oz). The breeding male has olive back, shoulders, rump and vent. The flight feathers are brownish-black. It has a slate gray neck, crown and eyeline. The underside is a gray-white. The female is similar to the male, but is much duller and has a greener tinge to the underside. The Tennessee Warbler has long wings, short tail and a thin, pointy bill. Juveniles and first-year birds are quite similar to the female.
The Tennessee Warblers resembles female Black-throated Blue Warbler, which is another member of the New World warblers. The only difference is that the Black-throated Blue Warbler has a darker cheek and two white wing spots.
This bird can be confused with the Red-eyed Vireo, which is larger, moves more deliberately and sings almost constantly. The Orange-crowned Warbler can also look similar, but lacks the white eyebrow, grayer-brown above and has yellow under-tail coverts.
The song has three parts, which can be repeated endlessly:"tecky tecky tecky tick tick tick tick tyew!tyew!tyew!tyew!" It's call is a sharp "tyick". The flight call is a buzzy "zzee".