Strix (genus)

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Strix owls

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Strigiformes
Family:	Strigidae
Genus:	Strix Linnaeus, 1758

Species

c.15, see text.

Strix is a genus of owls. They belong to the typical owl family Strigidae, one of the two generally accepted living families of owls, with the other being the barn-owls (Tytonidae).

These are medium-sized to largish powerful owls. They do not have ear tufts and most are highly nocturnal woodland birds. Most live on small mammals, birds and reptiles.

[edit] Species

Spotted Wood Owl, Strix seloputo
Mottled Wood Owl, Strix ocellata
Brown Wood Owl, Strix leptogrammica
Tawny Owl, Strix aluco
Hume's Owl, Strix butleri
Spotted Owl, Strix occidentalis
- Northern Spotted Owl, Strix occidentalis caurina
Barred Owl, Strix varia
Fulvous Owl, Strix fulvescens
Rusty-barred Owl, Strix hylophila
Rufous-legged Owl, Strix rufipes
Chaco Owl, Strix chacoensis
Ural Owl, Strix uralensis
Pere David's Owl, Strix davidi
Great Grey Owl, Strix nebulosa
African Wood Owl, Strix woodfordii

The genus Strix is well-represented in the fossil record. Being a fairly generic type of strigid owl, they were probably the first truly modern strigids to evolve. However, it is not certain whether several of the species usually placed in this genus indeed belong here.

For example, "Strix" brevis from the Early or Middle Miocene of Wintershof West, Germany, is now placed in Intutula; similarly, the supposed Mascarene species of this genus, "Strix" murivora, and "Strix" sauzieri and "Strix" newtoni were early misidentifications of male Rodrigues Owls, and female and male Mauritius Owls, respectively. These belong to another genus altogether.

"Strix" edwardsi from the Late Miocene of La Grive St. Alban, France, while being a strigid owl, has not at present been identified to genus; it might also belong into the European Ninox-like group^{[citation needed]}.

"Strix" perpasta (Late Miocene - Early Pliocene of Gargano Peninsula, Italy) does not appear to belong into this genus either (Olson 1985:131). It is sometimes considered a junior synonym of a Brown Fish-owl paleosubspecies (Mlíkovský 2002).

UMMP V31030, a coracoid from the Rexroad Formation (Late Pliocene) of Kansas (USA), cannot be conclusively assgned to either the present genus or Bubo (Feduccia 1970).

Generally accepted fossil forms of Strix are:

Strix collongensis (Early Miocene of France)
Strix dakota (Early Miocene of South Dakota, USA) - tentatively placed here
Strix sp. (Late Miocene of Nebraska, USA)
Strix sp. (Late Miocene of Sansan, France) - formerly Strix ignota which is a nomen nudum
Strix intermedia (Early - Middle Pleistocene of EC Europe) - may be paleosubspecies of S. aluco
Strix brea (Late Pleistocene of SW North America)
Strix sp. (Late Pleistocene of Ladds, USA)

[edit] References

Feduccia, J. Alan (1970): Some birds of prey from the Upper Pliocene of Kansas. Auk 87(4): 795-797. PDF fulltext

Mlíkovský, Jirí (2002): Cenozoic Birds of the World, Part 1: Europe: 215. Ninox Press, Prague. ISBN 80-901105-3-8 PDF fulltext

Olson, Storrs L. (1985): Section IX.C. Strigiformes. In: Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): Avian Biology 8: 129-132. Academic Press, New York.