Small Whitethroat (Sylvia minula) - HBW 11, p. 696

Taxonomy: Sylvia minula Hume, 1873, Bahawalpur, Pakistan.
Systematics of this species and S. curruca and S. althaea controversial. All three traditionally considered conspecific, but recent exhaustive phenotypic and genetic studies suggest that they should be treated as separate species, differing not only genetically but also vocally and in size (but less markedly in plumage); in parts of Asia where they breed very close to each other, they are segregated ecologically and altitudinally. The three appear to form a highly distinct clade (S. hortensis and S. leucomelaena being their closest relatives). Studies indicate additionally that race margelanica of present species represents a fourth species; relevant data on E populations, however, still inadequate or lacking, and further research needed to clarify systematic status of this race. Proposed race snigirewskii (from Turkmenistan) largely inseparable from, and therefore synonymized with, nominate; jaxartica (S Kazakhstan) falls within range of clinal variation of nominate, with which likewise synonymized; poorly differentiated chuancheica (Upper Huang He, S of Gobi, in N China) included within margelanica. Two subspecies recognized.