Mergus Albellus, also known as the Smew, is a species of duck native to Europe and Asia. This small diving duck has a distinctive appearance with its white and black plumage. There are several synonyms for Mergus Albellus, and they include Hooded Smew, White Nun, European Smew, and White Smew. The Hooded Smew is the name given to the male of the species, which has a rounded white crest on its head. The White Nun is another name for this bird due to its resemblance to a nun's headdress. The European Smew is used to denote its occurrence in Europe, while White Smew is a simpler version of the name.