Fig. 13From: Integrative taxonomy of the Plain-backed Thrush (Zoothera mollissima) complex (Aves, Turdidae) reveals cryptic species, including a new speciesScatter plot of principal component analysis of four song variables (duration, top frequency, bottom frequency, frequency bandwidth and peak frequency of strophes) of the Z. mollissima–Z. dixoni complex. The birds labelled ‘Alpine Thrush/“Yunnan Thrush” Z. mollissima (?) Yun’ were only observed in the field and their identification was therefore not confirmed by molecular markersBack to article page