Large-billed Crow (Corvus macrorhynchos) - HBW 14, p. 631

Taxonomy: Corvus Macrorhynchos Wagler, 1827, Java.
Taxonomy confusing owing to large number of races covering wide geographical area. Formerly included in C. coronoides, and listed as C. levaillantii in some older literature. Races probably represent several different species. In Indian Subcontinent, small race culminatus meets larger Himalayan intermedius; the two differ both vocally and in some behavioural aspects, but it is uncertain where the species limits are in relation to the lowland Bengal race levaillantii. In a recent study, four species tentatively proposed: "C. japonensis" (with races mandshuricus, connectens, osai, tibetosinensis and intermedius), "C. levaillantii" (with culminatus and colonorum), "C. macrorhynchos" and "C. philippinus". Subsequent study, however, has indicated that osai and connectens are not closely related to N Japanese forms, and, indeed, japonensis and mandshuricus behave as two species on the island of Sakhalin, with no mixed pairs found in overlap zone (C Sakhalin). These factors suggest that as many as seven species may be a reasonable assessment of the complex, but more research is required, not only through genetic and vocal comparisons, but also involving investigation of their parasitic lice (Mallophaga) and whether differences between races is gradual or abrupt. Race intermedius intergrades with tibetosinensis. Other proposed races are hondoensis and borealis (subsumed in japonensis), andamanensis (in levaillantii), anthracinus (in culminatus), hassi, mengtszensis and hainanus (in colonorum) and timoriensis (in nominate). With such a complicated species, however, one or two of these, especially anthracinus of Sri Lanka and andamanensis of the Andamans, could well be resurrected following a comprehensive review. Eleven subspecies currently recognized.