Hooded Crow (Corvus cornix) - HBW 14, p. 630

Taxonomy: Corvus Cornix Linnaeus, 1758, Sweden.
Thought to form a superspecies with C. corone, possibly also including C. pectoralis; was for long treated as conspecific with former. Situation complex, as narrow bands of hybridization between present species and C. corone exist across Scotland, through C Europe, in C Siberia and in C Asia, but striking plumage differences, subtle differences in vocalizations, and both narrowness and plasticity of hybrid zones all suggest that speciation has been at least partially achieved. British Is present a most interesting distributional jigsaw, with present species throughout Ireland, I of Man, N Scotland and Scottish isles, being replaced by C. corone over England, Wales and S Scotland; this suggests that present species had colonized from E, probably being the original British crow, but N-spreading C. corone from France or Spain colonized S England; meanwhile, Ireland and I of Man had separated from mainland Britain before England became separated from continental Europe. The spread continues today, with Scottish band of hybrids creeping N as black-plumage genes obliterate grey genes. Nominate race intergrades with sharpii in region of Urals. In E Europe and W Asia there is a cline of increasing paleness and smaller size from N to S, but complicated by bleaching, and several other described races are best treated as synonyms: thus, khozaricus (described from S Russia) is synonymized with nominate, and kaukasicus (Caucasus region), sardonius (Sardinia), italicus (Italy) and minos (Crete) are treated as synonyms of sharpii. Extreme S race, pallescens, is at palest end of cline, is relatively small and rather weak-billed, and contrasts markedly with the almost black-and-white, large-billed capellanus of Iraq and extreme SW Iran, suggesting that latter may well have evolved to full species level. Four subspecies recognized.