The brown creeper is quite vocal, but its high-pitched vocalizations are easily missed. It is generally solitary, but it sometimes migrates and winters with flocks of titmice, nuthatches, and kinglets. Polytypic (15 ssp.; 9 north of United States-Mexico border ). Length 5.3".

Distinctive shape and foraging behavior. Male and female: identical plumage; male larger. Cryptic upperparts streaked brown, buff, and black; underparts pale with warm wash on flanks; rump buff, tawny, or rufous. Flight: broad, pale wing stripe at base of flight feathers prominent in flight.

Subspecies north of the United States-Mexico border divide into 3 groups: western birds (alascensis, occidentalis, stewarti, phillipsi, zelotes, montana) are small, dark, and long billed; eastern birds (americana, nigrescens) are larger, generally paler, and shorter billed;