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.
Maritime, Fluvial and Harbour Museum of Rouen whale (on loan from the Natural History Museum of Rouen) is exhibited in the centre of the museum. It is a fin whale which was 7 years old when it died after grounding on a beach. A 38-metre barge, the "Pompon Rouge", is exhibited in the courtyard of the museum. Its hold has been transformed into an exhibition room about river navigation, including a model of a lock. In addition, there are regular temporary exhibitions on a variety of topics, such as the Rouen transporter bridge or the vikings. The museum is located in a former port building, Building 13,