Goldeneye are small tree-hole nesting northern hemisphere

Northern Hemisphere

The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...

 seaducks belonging to the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Bucephala. Their plumage is black and white, and they eat fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s and other marine life.

The Bufflehead

Bufflehead

The Bufflehead is a small American sea duck of the genus Bucephala, the goldeneyes. This species was first described by Linnaeus in his Systema naturae in 1758 as Anas albeola.-Description:...

 was formerly separated in its own genus Charitonetta, while the goldeneyes proper were mistakenly placed in Clangula, the genus of the Long-tailed Duck

Long-tailed Duck

The Long-tailed Duck or Oldsquaw is a medium-sized sea duck. It is the only living member of its genus, Clangula; this was formerly used for the goldeneyes, with the Long-tailed Duck being placed in Harelda...

 which at that time was placed in Harelda.

The three living species are

• Common Goldeneye
  Common Goldeneye
  The Common Goldeneye is a medium-sized sea duck of the genus Bucephala, the goldeneyes. Their closest relative is the similar Barrow's Goldeneye....
  
   Bucephala clangula
• Barrow's Goldeneye
  Barrow's Goldeneye
  Barrow's Goldeneye is a medium-sized sea duck of the genus Bucephala, the goldeneyes. This bird was named after Sir John Barrow....
  
   Bucephala islandica
• Bufflehead
  Bufflehead
  The Bufflehead is a small American sea duck of the genus Bucephala, the goldeneyes. This species was first described by Linnaeus in his Systema naturae in 1758 as Anas albeola.-Description:...
  
   Bucephala albeola

Known fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 taxa are:

• Bucephala cereti (Sajóvölgyi Middle Miocene of Mátraszõlõs, Hungary - Late Pliocene of Chilhac, France)
• Bucephala ossivalis (Late Miocene/Early Pliocene of Bone Valley, USA), which was very similar to the Common Goldeneye and may even have been a paleosubspecies or direct ancestor
• Bucephala fossilis (Late Pliocene of California, USA)
• Bucephala angustipes (Early Pleistocene of C Europe)
• Bucephala sp. (Early Pleistocene of Dursunlu, Turkey: Louchart et al. 1998)