there are three widespread subspecies of barn swallows in Eurasia: H. r. rustica in Europe and western Russia, H. r. tytleri in the Lake Baikal region of Russia and Mongolia, and H. r. gutturalis, in eastern Russia, China, Korea and Japan. Last year, we drove west-to-east through the breeding ranges of these three subspecies, with the primary goal of describing and sampling the contact areas (and possible hybrid zones) between the subspecies.
is considerable. Adults with unbroken black pectoral bands are most likely to be
nominate rustica, and, in Asia, birds with almost uniform chestnut underparts to be
tytleri but the latter intergrades with gutturalis (although not perhaps with the nominate
form in the north of its range).