Nantes Ducks are a relatively new breed of duck. In fact, they are a half-breed duck, and the line is regularly crossed with wild ducks every year.
The birds have short legs and longish breasts.
They reach full size at 4 months of age, at which time they will weigh about 4 1/2 pounds (2 kg.)
They are brought to markets in the spring. Before sale, the carcasses have the heads removed, and are bled.
The Nantes Ducks is really from the Challans are in the Vendée. The Nantes affiliation in its name comes from being sold in the markets of Nantes, or shipped from there to Paris.
Davidson, Alan. The Penguin Companion to Food. London: The Penguin Group, 2002. page 311.
Toussaint-Samat. Maguelonne. A history of food. Hoboken, New Jersey: Wiley-Blackwell. 1994. Page 348.