The mountain wren is 10.5 to 11.5 cm (4.1 to 4.5 in) long and has a mean weight of 11.8 g (0.42 oz). The adult of the nominate subspecies has a rufous brown forehead and crown, a less reddish brown nape, shoulders, back, and rump, and a rufous brown tail with narrow black bars. The folded wings also appear barred. It has a buffy brown supercilium with a darker brown line behind the eye and warm buff cheeks. The throat and chest are also warm buff, the belly a paler buff, the flanks buffy brown with darker bars, and the vent grayish, also with darker bars. The juvenile's supercilium and upperparts are less warm and its underparts dull gray brown with darker speckles.Taken from: Wikipedia
