Eastern Spot-billed Duck
Anas zonorhyncha
Eastern Spot-billed Ducks are mainly vegetarian dabbling ducks. Vocalisations include a loud quack made by females, and a deeper, quieter rab sound by males.
They are sometimes known as the Chinese Spot-bill, though the other species of spot-billed duck also breeds in China. Inhabiting various types of inland and coastal (both tidal and brackish) wetlands, they are found from Russia, Mongolia, Sakhalin, Korea and Japan to eastern China. In winter they move to southern China and may reach Thailand and Cambodia.
The most obvious difference between Eastern and Indian Spot-billed Ducks is that the former have a second, incomplete, line on their face from bill base towards the ear coverts. There is also no red patch at the base of the bill.
This species lays 6–12 whitish eggs, which are incubated for ~26 days. Wild nesting females, young and eggs may be predated by water and marsh-dwelling snakes. In aviculture, they breed readily and care should be taken enclosing them with other ducks. They readily hybridise with several closely and not-so-closely related species, and these offspring are frequently fertile.
FURTHER READING
The Chinese Spot-billed Duck, Harteman Wildfowl https://www.harteman.nl/pages/anaszonorhyncha