Common Stonechat (Saxicola torquatus) - HBW 10, p. 781

Taxonomy: (Motacilla) torquata Linn aeus, 1766, Cape of Good Hope, South Africa.
Has been considered conspecific with S. dacotiae, but morphological differences sufficient to warrant treatment as two separate species; has also been treated as conspecific with S. tectes and S. leucurus. Recently proposed that races form three distinct species, European S. rubicola (including race hibernans), Siberian S. maurus (including variegatus, armenicus, indicus, przewalskii and stejnegeri) and African S. torquatus (remaining races); extent to which these groups satisfy any criteria for species recognition, however, is unclear, and variation within groups is considerable. Alternatively, further splitting could be argued for, e.g. in the case of rather distinct and apparently parapatrically abutting forms indicus and przewalskii. Variation also exists within races, and several taxa may be unworthy of recognition while others may deserve reinstatement. Birds on Sicily included in rubicola, but most closely resemble maurus (hence a challenge to the splitting of latter), and have been named archimedes. Races adamauae (N & W Cameroon) and pallidigula (Cameroon Mountain and Bioko I) are treated as synonyms of salax, and altivagus is included in promiscuus. Racial affiliation of population recently found breeding in NW Thailand unknown. Twenty-four subspecies recognized.