Some aspects of relationships of two subspecies of the Common Stonechat (Saxicola torquata) in Northern Caucasus

Abstract

Some aspects of relationships of two subspecies of the Common Stonechat (Saxicola torquata s.l.) in Northern Caucasus were analysed with use of collections of the Natural History Museum of Kharkiv National University and own field data gathered in expeditions of 1998 year in Dagestan Republic (Russia). Stonechats of variegata race (Eastern Palearctic group of subspecies) may be reliably discerned from Caucasian representatives of rubicola race (Western Palearctic group of subspecies) by wing length. Caucasian representatives of rubicola race differ from Eastern-Ukrainian individuals of the same subspecies by size but these differences are not significant. Contrary to the opinion expressed in major compendiums the range of rubicola race spreads to the east up to the borders of Caucasus mountains. There is a clear altitudinal and habitat separation of rubicola and variegata populations in Northern Caucasus. The data on distribution and ecology of two races of Common Stonechat in Northern Caucasus corroborate the treatment of Western and Eastern Palearctic groups of subspecies as separate species based on molecular phylogeny.