The Northern Diver is a species of AUK, a type of seabird that is found in the northern hemisphere. It is a medium-sized bird with a black head and white body, and it is known for its ability to dive underwater to catch fish. The Northern Diver is also known as the Common Murre or the Guillemot. It is an important part of the marine ecosystem, as it helps to keep the population of fish in balance.