Yellow-nib or Chinese Grey Duck.
This East Asiatic representative of the spotted-bill has of late years proved to occur quite commonly is Assam, and also to be found in the Shan States and Upper Burmah. Although it never has the red spots at the base of the bill so characteristic of the spotted-bill of India, this is not the chief distinction, as these spots may be absent in perfectly adult and otherwise normal spotted-bills ; I have seen one such in the London " Zoo," which was the father of perfectly normal young when paired to a female which showed the spots.
The most striking point about the- yellow-nib is the fact that the wing-bar is blue instead of green, and that the white on the inner quills never forms more than a border, and does not take up all the outer half of the feather ; moreover, the plumage is not so distinctly marked as that of the spotted-bill—although there is a very distinct whitish eyebrow—and is much darker below, the belly as well as the stern being blackish. The bill is apparently rather smaller, and is blacker, the yellow tip being smaller.
The yellow-nib occurs sometimes in quite large flocks—as many as forty have been seen together in Lakhimpur— but small parties of pairs are commoner ; when thus few in numbers they associate with other surface-feeding ducks; they are wild, like ducks in Lakhimpur generally.
The eggs have been taken in Dibrugarh and the Shan States, and are like spotted-bills' eggs, but run smaller. The best known haunts of this bird are from eastern Mongolia east and through China and Japan to the Kuriles; no doubt in the northern part of its range it is migratory, and it would appear to have a longer wing than our resident Indian spotted-bill.