About Corvus macrorhynchos Wagler, 1827
The large-billed crow (Corvus macrorhynchos Wagler, 1827) is a relatively large, entirely black crow. It measures 46–59 cm (18–23 in) in length and weighs 450–1,000 g (16–35 oz). It has a large black bill with an arched culmen; the base of the culmen is hidden by a layer of overlapping black rictal bristles. Its glossy black plumage carries a purple sheen, and the bases of its neck feathers are pale grey. Elongated hackle feathers grow on its throat. Its irises are dark brown, and its legs are black. The sexes have similar plumage, but on average, females are smaller than males and have a less arched culmen. Juveniles have less glossy plumage and smoky blue irises instead of brown. Subspecies of this crow differ in overall body size, bill size, and the intensity of plumage gloss. The largest subspecies is C. m. japonensis, which has a bill 70–80 mm (2.8–3.1 in) long. The smallest subspecies is C. m. culminatus, with a bill measuring 52–67 mm (2.0–2.6 in) in length. The calls of this species are complex and hard to compare directly, but in Nepal, the smaller subspecies C. m. culminatus has a higher-pitched voice than the larger C. m. intermedius. This species has an extensive distribution range that stretches from the northeastern Asian seaboard west to Afghanistan and eastern Iran, extends through South and Southeast Asia, and reaches southeast to the Lesser Sundas and Cambodia. It can be found in woodland, parks and gardens, and cultivated regions that have at least some trees. In the southern part of its range, it occupies more open country, where it does not compete with the common raven and carrion crow that live in the northern portion of its range.
