Bay Wren
Cantorchilus nigricapillus
The bay wren is 12.6 to 15.6 cm (5.0 to 6.1 in) long. Eight specimens from Panama weighed 17.7 to 26.3 g (0.62 to 0.93 oz). Adults of the nominate subspecies have a black face with a narrow white supercilium, a partial eyering, and a white patch at the back of the cheek. Their crown and nape are black and the rest of the upperparts are rich chestnut. The tail is a rich brown with bold black bars. The throat and breast are white, transitioning to rufous brown on the lower belly and flanks. Black bars cross the underparts from the breast to the vent area. Voice: The bay wren's song is loud, "a rapid repetition of clear, rich-toned, slurred, ringing whistles, trills, and warbles" sometimes given antiphonally. The species has a number of calls.
ID text from Wikipedia, CC BY-SA 4.0

Riverside Wren
Cantorchilus semibadius
The riverside wren is 13 to 14 cm (5.1 to 5.5 in) long and weighs 17 g (0.60 oz). The adults have a bright orange-brown crown; chestnut nape, back, and rump; and a blackish tail with buff-white bars. They have a black-over-white supercilium and the rest of the face is streaked and spotted black and white. From throat to vent their underparts are pale gray with narrow black bars; the gray becomes somewhat buffy to the rear. Juveniles are duller overall, have fine black scaling on the crown, and the underparts' black bars are not as crisp. Voice: Both sexes of riverside wren sing, repeated "loud ringing phrases" and followed by different phrases, also repeated. Their calls include "harsh churr and various clear tinkling notes".
ID text from Wikipedia, CC BY-SA 4.0
Where you might meet both
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Play today's Daily BirdPhotos and recordings are credited to their authors under the licence shown. Full profiles: Bay Wren and Riverside Wren.