Abstract

The underwing pattern provides a critical field character for separating male European Stonechats Saxicola rubicola from Siberian Stonechats S. maurus and Amur Stonechats S. stejnegeri, two taxa collectively known as ‘Eastern Stonechats’. This paper reviews underwing variation in these taxa, based on field observations and photographs of birds from across their breeding and migratory ranges. While adult male ‘Eastern Stonechats’ invariably show jet-black underwing-coverts and axillaries, young males exhibit a wide range of intermediate patterns. In contrast, male European Stonechats show a grey-toned underwing, with the darkest area of the underwing-coverts located distally, unlike the proximal concentration of dark feathers in ‘Eastern Stonechats’. Although rarely visible for more than a fleeting moment, underwing pattern – when well observed or photographed – offers the most reliable feature for identifying males of the two species regardless of age.