Rouens come in two distinct shapes. The Non-Industrial Rouen and the Production Rouen, which isn't considered endangered.
Rouen duck - Wikipedia
Rouen Ducks - Not Sexed
Rouen - Non-Industrial Duck - The Livestock Conservancy
Breeds of Domestic Ducks
The Livestock Conservancy - The famous poultry breeder William Cook created several Orpington duck varieties, including the Blue, Buff, and Black Orpington after blending Cayuga, Runner, Aylesbury, and Rouen ducks. His goal
Duck Breed Focus - Rouen Duck breeds, Duck and ducklings, Pet ducks
Rouen - Non-Industrial Duck - The Livestock Conservancy
Ducks Rouen, Peking & Muscovy Manitowoc, WI - Official Website
Khaki Campbell Duck - Breed Profile - Backyard Poultry
Rouen Duck · eFowl