Domestic ducks weed rice paddies, forget how to brood, and outnumber geese
Almost every farmyard duck descends from wild mallards tamed in southern China around 2000 BC, probably by rice farmers. Ducks still earn their keep in Asian paddies, gobbling pests and fertilising the crop, so one field yields rice and poultry together. China alone produces more than 80 percent of the world's duck meat.
Genome studies point to a single domestication of the mallard during the Neolithic, followed by fast selection for either meat or eggs. Archaeology offers little, and the oldest written mentions come from Han Chinese texts of about 500 BC. Ancient Egyptians hunted wild mallards heavily without taming them, and Roman farmers apparently had to collect wild eggs to stock their duck yards. The Muscovy duck, a separate genus, was domesticated in Mexico and South America.
Domestication reshaped the bird. Wild mallards pair up and defend territory; farm ducks are mostly promiscuous and calmer, yet they still breed freely with wild mallards and produce fertile young. Weights now range from about 0.7 kilograms for a small Appleyard to 4.6 kilograms for a hefty Aylesbury, against roughly 1.1 kilograms for a wild bird. A typical breed lays around 200 eggs a year, while the Indian Runner can top 300.
Many domestic females have lost the knack of sitting on their eggs, so farmers long slipped duck eggs under broody hens, and incubators do the job now. That creates a snag: ducklings need preen oil from their mother to stay waterproof, hens make less of it, and machines make none, so chicks rely on it until their own feathers and tail gland take over.
Ducks shrug off many bird diseases, including duck plague, though the H5N1 strain of avian flu can hit them hard. In 2021 around 4.3 billion were slaughtered worldwide. Culture has embraced them too, from Beatrix Potter's Jemima Puddle-Duck in 1908 to the oboe that plays the duck in Prokofiev's Peter and the Wolf, and Donald Duck belongs to the American Pekin breed.
Source: Domestic duck
