Microcerculus

Abstract: We describe for the first time the nests of the Wing-banded Wren (Microcerculus bambla), a little-known species of Trogoldytidae from northcentral South America. Two nests were discovered in French Guiana during the rainy season of 1999. Both nests were in abandoned termite mounds attached to the undersides of fallen trees. Chambers of the two nests were lined with a mat of dead leaf fragments. Each nest contained a single, well-feathered nestling that disappeared, possibly due to fledging, within a few days of nest discovery. Although we did not observe nest building, we suspect that other termitaria-nesting birds at our study site, such as Puffbirds (Bucconidae) or Jacamars (Galbulidae) excavated the chambers. Thus, both Microcerculus species with described nests, the Nightingale Wren (M. marginatus) and the Wing-banded Wren, apparently are second- ary cavity nesters. Received 19 Dec. 1999, accepted 20 Oct. 2001. Species of the genus Microcerculus occur exclusively in the undergrowth of humid trop- ical and subtropical forests and are among the least-known members of the Troglodytidae (Stiles 1983, Hilty and Brown 1986, Ridgely and Tudor 1994, Brewer and Mackay 2001). This genus comprises species of small, short- tailed, dark, and highly elusive wrens that of- ten are difficult to observe (Slud 1958, Stiles 1983, Tostain et al. 1992, Ridgely and Tudor 1994). These species usually are not rare but their cryptic coloration and secretive behavior cause field researchers to rely mainly on vo- calizations to detect them (Meyer de Schauen-