merganser

Typical mergansers
Red-breasted Merganser (Mergus serrator)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Subclass: Neornithes Infraclass: Neognathae (unranked): Galloanserae Order: Anseriformes Family: Anatidae Subfamily: Merginae Genus: Mergus Linnaeus, 1758
Species
Mergus australis (extinct) Mergus merganser Mergus octosetaceus Mergus serrator Mergus squamatus

Mergus^[1] is the genus of the typical mergansers, fish-eating ducks in the seaduck subfamily (Merginae). The Hooded Merganser, often termed Mergus cucullatus, is not of this genus but closely related. The other "aberrant" merganser, the Smew (Mergellus albellus), is phylogenetically closer to goldeneyes (Bucephala).

Although they are seaducks, most of the mergansers prefer riverine habitats, with only the Red-breasted Merganser being common at sea. These large fish-eaters have serrated edges to their bills to help them grip their prey. Along with the Smew and Hooded Merganser, they are therefore often known as "sawbills". The goldeneyes, on the other hand, feed mainly on mollusks, and therefore have a more typical duck-bill. In other traits, however, the genera Mergus, Lophodytes, Mergellus and Bucephala are very similar; uniquely among all Anseriformes, they do not have notches at the hind margin of their sternum, but holes surrounded by bone.^[2]

Species

• Auckland Islands Merganser, Mergus australis (extinct, c.1902)
• Common Merganser or Goosander, Mergus merganser
• Brazilian Merganser, Mergus octosetaceus
• Red-breasted Merganser, Mergus serrator
• Chinese Merganser, Mergus squamatus

Some fossil members of this genus have been described:

• Mergus miscellus is known from the Middle Miocene Calvert Formation (Barstovian, c.14 million years ago) of Virginia, USA.
• Mergus connectens lived in the Early Pleistocene about 2-1 million years ago, in Central and Eastern Europe.^[3]

The Early Oligocene booby "Sula" ronzoni was at first mistakenly believed to be a typical merganser^[4]. A Late Badenian (13-12 million years ago) fossil sometimes attributed to Mergus, found in the Sajóvölgyi Formation of Mátraszõlõs, Hungary, probably belongs to Mergellus^[5]. The affiliations of the mysterious "Anas" albae from the Messinian (c.7-5 million years ago) of Hungary are undetermined; it was initially believed to be a typical merganser too^[6].

Footnotes

References

Wikimedia Commons has media related to: Mergus

• Arnott, W.G. (1964): Notes on Gavia and Mergvs in Latin Authors. Classical Quarterly (New Series) 14(2): 249-262. First page image
• Gál, Erika; Hír, János; Kessler, Eugén & Kókay, József (1998-99): Középsõ-miocén õsmaradványok, a Mátraszõlõs, Rákóczi-kápolna alatti útbevágásból. I. A Mátraszõlõs 1. lelõhely [Middle Miocene fossils from the sections at the Rákóczi chapel at Mátraszőlős. Locality Mátraszõlõs I.]. Folia Historico Naturalia Musei Matraensis 23: 33-78. [Hungarian with English abstract] PDF fulltext
• Livezey, Bradley C. (1986): A phylogenetic analysis of recent anseriform genera using morphological characters. Auk 103(4): 737-754. PDF fulltext DjVu fulltext
• Mlíkovský, Jirí (2002a): Early Pleistocene birds of Stránská skála, Czech Republic: 2. Absolon's cave. Sylvia 38: 19-28 [English with Czech abstract]. PDF fulltext
• Mlíkovský, Jirí (2002b): Cenozoic Birds of the World, Part 1: Europe. Ninox Press, Prague. ISBN 80-901105-3-8 PDF fulltext