Cryptic new bird family discovered

Spotted Wren-babbler trapped in Wuyi Shan, China, April 2013. Photo: Per Alström.
Spotted Wren-babbler trapped in Wuyi Shan, China, April 2013. Photo: Per Alström.
While birders are accustomed to DNA analysis identifying new species among seemingly similar forms, it has now uncovered whole new family.

A team led by Per Alström – associated with both the Swedish University of Agricultural Sciences and the Chinese Academy of Sciences – used one of the largest repositiories of the DNA sequence data of true passerines to identify the main clades (or evolutionary branches that share a common ancestor) of the Passerida, the group that includes tits, warblers, chats, flycatchers, waxwings, treecreepers and many other largely insect-eating songbirds.

While several singular groups were found to be wrongly classified, one species in particular stood out as being entirely wrongly affiliated – Spotted Wren-babbler from China. The species – Elachura formosa – was already known but believed to be a member of the babbler family, Timaliidae, and was included in the genus Spelaeornis along with eight other very similar-looking species.

Spotted Wren-babbler's voice is different to almost any other Asian passerine. Photo:  Ramki Sreenivasan (Conservation India).

Spotted Wren-babbler was different enough to have a new family created for it: Elachuridae. The species is so far out on its own branch as to be the sole representative of one of the 10 primary lineages of the Passerida, though its precise relationship with the related flycatchers and chats, treecreepers and – perhaps closest of all – waxwings is unknown at present. It appears to be closely derived from one of the earliest or most basal passerine groups.

The species is an amazing example of parallel evolution with the true wren-babblers and true wrens, but its song is very different to other Asian passerines, as well as showing a well-supported large phylogenetic separation.