The fawn-breasted wren (Cantorchilus guarayanus) is a species of bird in the family Troglodytidae. It is found in Bolivia, Brazil, and Paraguay. The fawn-breasted wren has sometimes been treated as conspecific with the buff-breasted wren (Cantorchilus leucotis), though they have very different vocalizations. The species is monotypic.
The fawn-breasted wren is 13.5 cm (5.3 in) long and weighs 13 to 14 g (0.46 to 0.49 oz). Adults have a plain medium brown crown and upperparts that becomes rufescent on the lower back and rump. Their tail is reddish brown with crisp black bars. They have a narrow white supercilium mostly behind the eye, cheeks mottled gray-white and blackish, and black malar and moustachial stripes. Their chin is whitish, the chest a warm orange-buff, and the belly and vent area a deeper orange-buff. Juveniles are similar but their facial markings are less distinct.
The fawn-breasted wren is found across much of northeastern Bolivia, a fairly thin slice of adjacent western Brazil, and a small part of northeastern Paraguay. It inhabits várzea scrubland and secondary forest, mostly near water...