Mergansers are a type of diving duck known for their long, slender bills and unique hunting tactics. While "mergansers" is the most commonly used term, there are some synonyms that could be used to describe these birds. For example, the term "sawbills" refers to the serrated appearance of their bills, while "fish ducks" highlights their preference for consuming fish. Other synonyms include "goosanders," which is used in Europe, and "harlequin ducks," a term that specifically refers to the North American species. Regardless of what term is used, it is clear that mergansers are fascinating creatures with a distinctive set of characteristics.