FAMILY TROGLODYTIDAE 



55 



M. A. Carriker, Jr. (Ann. Carnegie Mus., vol. VI, 1910, p. 752), in 

 his account of this species in Costa Rica, says of it that he found a pair 

 on a river "high in the mountains above Ujarras de Terraba, where the 

 stream came tumbling and foaming down through a deep gorge. Their 

 discovery was caused by first finding the nest as I was climbing up a 

 precipitous wall of rock beside a waterfall. It was a rather flat, cup- 

 shaped structure, built almost entirely of moss and placed on a narrow 

 shelf of rock on the brink of the falls. It contained one partially incu- 

 bated egg which was blown, but later misplaced and lost. ... In color 

 it was plain dull white, of the usual shape and size of the Water Ouzel 

 of the United States." 



Family TROGLODYTIDAE: Wrens, Cucaracheros 



Wrens are widespread in Panama, where they are found at all eleva- 

 tions. Twenty-two species, all permanent residents, are known from 

 the Republic. They favor thick undergrowth and the lower levels in 

 forests, where they feed on insects and other arthropods. The House 

 Wren is common around human settlements. 



The family has a wide vocal repertoire; some members are among 

 the finest singers in Panama, and an increasing number are known to 

 sing antiphonally. Song is now being used as a taxonomic character; 

 it has proved useful in determining the relationships of some variable 

 and widely dispersed Neotropical species, such as Microcerculus mar- 

 ginatus. 



Most wrens build domed nests with an entrance at one side; a few 

 species nest in cavities. When not actually breeding, individuals of cer- 

 tain species roost communally, often in a "dormitory" nest built for 

 this purpose, or in a natural cavity. 



[Although now usually placed in the Mimidae, new evidence indi- 

 cates that the monotypic genus Donacobius should be included in the 

 Troglodytidae. The species was at one time referred to as the "Wren- 

 Thrasher" and was considered to be a wrenlike thrasher or a thrasher- 

 like wren (Fuertes, Bird-Lore, vol. 13, 1913, p. 342), but its wrenlike 

 attributes have of late been overlooked. Donacobius is considerably 

 larger than most wrens, but is scarcely, if any, larger than the larger 

 species of Campylorhynchus, and immatures, as well as the Bolivian 

 race, D. a. albovittatus, which have a white superciliary stripe, bear a 

 striking resemblance to Campylorhynchus griseus. The males and fe- 

 males of Donacobius duet, which is a wrenlike trait. Olson and D. W. 



