Premnoplex brunnescens (P. L. Sclater, 1856)
--From Greeney 2011 (http://neotropical.birds.cornell.edu/portal/species/lifehistory?p_p_spp=...)--
Spotted Barbtails show remarkable variability in nest architecture, mostly in relation to the amount of material that adults bring and the degree to which surrounding material forms part of the nest. Nevertheless, most nests are of the same basic architectural design: large, globular, mossy balls with a downward facing entrance tube. The downward opening entrance into the nest chamber is slightly wider than tall, with the entrance flaring laterally, but with the height of the entrance maintained along the length of the tube. The inner chamber has an elevated front lip that serves to contain the nest contents as well as to form the inner portion of the entrance tube. Although this description applies to the majority of nests, many nests are variously constructed such that one or several portions of the outer nest structure are actually formed by part of the surrounding substrate. Thus, large portions of the inner chamber are often devoid of moss, and instead formed by the clay or wood to which the nest is attached.
So far as is known, Spotted Barbtails breed exclusively in riparian zones, directly over flowing mountain streams.