The Arctic diving bird term is composed of two species: the Murre (5 letters) and the AUK (3 letters). The Murre is a medium-sized seabird that is found in the North Atlantic and Arctic Oceans. It is a member of the Alcidae family, which includes puffins, guillemots, and other auks. The AUK is a type of seabird that is found in the Northern Hemisphere. It is a member of the Alcidae family and is closely related to the Murre. Both species are known for their ability to dive underwater in search of food.