Bay Wren

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. Juveniles have essentially the same pattern but are paler and with less well defined markings. The other subspecies vary from the nominate in the extent and intensity of some colors and the thickness and amount of barring.

The bay wren's range spans from Nicauagua to Ecuador. The subspecies are found thus:

C. n. costaricensis, from northeastern Nicaragua through Caribbean Costa Rica into western Panama C. n. castaneus, from west-central Panama's Veraguas Province to the Canal Zone C. n. odicus, Isla Escudo de Veraguas off the Caribbean coast of western Panama C. n. reditus, the Caribbean slope of eastern Panama C. n. schottii, from eastern Panama's Darién Province into Antioquia and Chocó Departments of northwestern Colombia C. n. connectens from Cauca and Nariño Departments in southwestern Colombia into Esmeraldas Province in far northern Ecuador C. n. nigricapillus western Ecuador from Esmeraldas south to El Oro Province The bay wren is closely tied to water over most of its range, though in Nicaragua the habitat is drier. It inhabits dense, fairly low, vegetation such as thickets along watercourses, overgrown clearings, roadsides, and the understory of secondary forest. It will occur in forest interiors if the undergrowth is sufficient.

The bay wren's diet appears to be entirely invertebrates. They forage by gleaning from foliage and branches and by probing hanging vegetation and tangles of vines.