Rouen duck Rouen duckling is identical to the Mallard duckling in terms of plumage coloring. In North America, two distinct types are bred: the common, or production-bred, variety that is larger than a Mallard but has a typical duck conformation, and the much larger and squarer standard-bred variety. The production variety normally weighs 6–8 lbs (2.7–3.6 kg) while the standard-bred weighs 9–12 lb (4.1–5.4 kg). Rouen ducklings can be distinguished from wild mallard ducklings by the presence of a second stripe which runs across their face, just under their eye, whereas mallard ducklings have only one stripe which runs across their eye.
Rouen an estimated population of 111,557. People from Rouen are known as "Rouennais". Rouen and its metropolitan area of 70 suburban communes form the Métropole Rouen Normandie, with 494,382 inhabitants at the 2010 census. In descending order of population, the largest of these suburbs are Sotteville-lès-Rouen, Saint-Étienne-du-Rouvray, Le Grand-Quevilly, Le Petit-Quevilly, and Mont-Saint-Aignan, each with a population exceeding 20,000. Rouen was founded by the Gaulish tribe of the Veliocasses, who controlled a large area in the lower Seine valley. They called it "Ratumacos"; the Romans called it "Rotomagus". It was considered the second city of Gallia Lugdunensis after Lugdunum (Lyon) itself.