Chinese goose

The Chinese goose is a breed of domesticated goose descended from the wild swan goose. Chinese geese differ from the wild birds in much larger size (up to 5–10 kg in males, 4–9 kg in females), and in having an often strongly developed basal knob on the upper side of the bill. The knob at the top of the beak is more prominent on males than females. By 6–8 weeks of age, the knob is already pronounced enough that it can be used for determining gender. Chinese geese are a close cousin of the African goose, a heavier breed also descended from the swan goose.