Horned owl

Taxobox
name = Horned owls and eagle-owls

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image_width = 200px
image_caption = Rock Eagle-owl, "Bubo bengalensis"
regnum = Animalia
phylum = Chordata
classis = Aves
subclassis = Neornithes
infraclassis = Neognathae
superordo = Neoaves
ordo = Strigiformes
familia = Strigidae
genus = "Bubo"
genus_authority = Duméril, 1806
subdivision_ranks = Species
subdivision = About one or two dozen, see text
synonyms ="Nyctea" Stephens, 1826 and see text

The American horned owls and the Old World eagle-owls make up the genus "Bubo", at least as traditionally circumscribed. This genus, depending on definition, contains about one or two dozen species of typical owls (family Strigidae) and occurs in many parts of the world. Some of the largest living Strigiformes are in "Bubo". Traditionally, only owls with ear-tufts were included here, but this is now known to be wrong.

ystematics

mtDNA cytochrome "b" sequence data supports the decision to consider the Snowy Owl an eagle-owl adapted to Arctic conditions and moving it into "Bubo", rendering the monotypic genus "Nyctea" invalid.Olsen "et al." (2002)]

The four fish-owls previously in the genus "Ketupa" were provisionally moved into "Bubo" as well [König "et al." (1999)] . However, the mtDNA cytochrome "b" data suggests that in this case, to make "Bubo" monophyletic the "Scotopelia" fishing-owls would also need to be included there. On the other hand, the genus then becomes quite large and ill-defined, and "Bubo" in the expanded sense seems to consist of 2 distinct clades. Thus, the fish- and fishing-owls can alternatively be united in "Ketupa" if some aberrant eagle-owls – at least the Barred, Spot-bellied and Usambara eagle-owls, perhaps also Fraser's Eagle-owl and maybe others – are moved into that genus too. As some enigmatic eagle-owls remain essentially unstudied and others – e.g. Verreaux's Eagle-owl – are of unresolved relationships, more research is needed.

Living species

The following living owls are usually included in "Bubo":
* Great Horned Owl, "Bubo virginianus"
** South American Great Horned Owl, "Bubo virginianus nacurutu"
* Magellanic Horned Owl, "Bubo magellanicus"
* Eurasian Eagle-owl, "Bubo bubo"
* Rock Eagle-owl, "Bubo bengalensis"
* Pharaoh Eagle-owl, "Bubo ascalaphus"
* Cape Eagle-owl, "Bubo capensis"
** Mackinder's Eagle-owl, "Bubo (capensis) mackinderi"
* Spotted Eagle-owl, "Bubo africanus"
* Greyish Eagle-owl, "Bubo cinerascens"
* Fraser's Eagle-owl, "Bubo poensis"
* Usambara Eagle-owl, "Bubo vosseleri"
* Spot-bellied Eagle-owl, "Bubo nipalensis"
* Barred Eagle-owl, "Bubo sumatranus"
* Shelley's Eagle-owl, "Bubo shelleyi"
* Verreaux's Eagle-owl, "Bubo lacteus"
* Dusky Eagle-owl, "Bubo coromandus"
* Akun Eagle-owl, "Bubo leucostictus"
* Philippine Eagle-owl, "Bubo philippensis"
* Snowy Owl, "Bubo scandiacus"

The fish- and fishing-owls are:
* Blakiston's Fish-owl, "Ketupa blakistoni" or "Bubo blakistoni"
* Brown Fish-owl, "Ketupa zeylonensis" or "Bubo zeylonensis"
* Tawny Fish-owl, "Ketupa flavipes" or "Bubo flavipes"
* Buffy Fish-owl, "Ketupa ketupu" or "Bubo ketupu"
* Pel's Fishing-owl, "Scotopelia peli" or "Bubo peli"
* Rufous Fishing-owl, "Scotopelia ussheri" or "Bubo ussheri"
* Vermiculated Fishing-owl, "Scotopelia bouvieri" or "Bubo bouvieri"

Fossil record

Named and distinct "Bubo" species are:
* "Bubo florianae" (Late Miocene of Csákvár, Hungary, tentatively placed here)
* "Bubo binagadensis" (Late Pleistocene of Binagady, Azerbaijan)
* Cuban Horned Owl, "Bubo osvaldoi" (LateVerify source|date=September 2008 Pleistocene of Cuba)

Some notable undescribed fossils of prehistoric horned owls, usually quite fragmentary remains, have also been recorded:
* "Bubo" sp. (Late Pliocene of Senèze, France) [Lambrecht (1933): p.616]
* "Bubo" sp. (Late Pliocene of Rębielice Królewskie, Poland; tentatively placed here) [Mlíkovský (2002)]
* "Bubo" sp. (Late Pleistocene of San Josecito Cavern, Mexico) [A single bone of a large horned owl distinct from "B. virginianus": Steadman "et al." (1994)]

Specimen UMMP V31030, a Late Pliocene coracoid from the Rexroad Formation of Kansas (USA), cannot be conclusively assgned to either the present genus or "Strix". This fossil is from a taxon similar in size to the Great Horned Owl ("B. virginianus") or the Great Grey Owl ("S. nebulosa"). [Feduccia (1970)]

The Pleistocene Sinclair Owl from California ("Bubo sinclairi") may have been a paleosubspecies of the Great Horned Owl [Howard (1947)] , while "Bubo insularis" has been considered a junior synonym of a Brown Fish-owl paleosubspecies [Mlíkovský (2002, 2003)] . Additional paleosubspecies are discussed on the appropriate species page.

Several presumed "Bubo" fossils have turned out to be from different birds. The Late Eocene/Early Oligocene eared owls "Bubo" incertus" and "Bubo" arvernensis" are now placed in the fossil barn-owl genera "Nocturnavis" and "Necrobyas", respectively. "Bubo" leptosteus" is now recognized as primitive owl in the genus "Minerva" (formerly "Protostrix"). "Bubo" poirreiri" from the Late Oligocene or Early Miocene of Saint-Gérard-le-Puy in France, is now placed in "Mioglaux".

On the other hand, the supposed fossil heron "Ardea" lignitum" from the Late Pliocene of Plaue-Rippersroda (Germany) was apparently an owl and close to "Bubo" or more probably actually belongs here. Given its age – about 2 million years ago or so – it may well be very close to the living Eurasian Eagle-owl. [Olson (1985): p.167, Mlíkovský (2002)] .

Footnotes

References

* (1970): Some birds of prey from the Upper Pliocene of Kansas. "Auk" 87(4): 795-797. [http://elibrary.unm.edu/sora/Auk/v087n04/DJVU/P0795-P0797.djvu DjVu fulltext] [http://elibrary.unm.edu/sora/Auk/v087n04/p0795-p0797.pdf PDF fulltext]
* (1999): "Owls: A guide to the owls of the world." Yale University Press, New Haven. ISBN 0300079206
* (1947): A preliminary survey of trends in avian evolution from Pleistocene to recent time. "Condor" 49(1): 10–13. [http://elibrary.unm.edu/sora/Condor/files/DJVU/v049n01/P0010-P0013.djvu DjVu fulltext] [http://elibrary.unm.edu/sora/Condor/files/issues/v049n01/p0010-p0013.pdf PDF fulltext]
* (1933): "Handbuch der Palaeornithologie" [Handbook of Paleornithology] . Gebrüder Bornträger, Berlin. [in German]
* (2002): "Cenozoic Birds of the World, Part 1: Europe". Ninox Press, Prague. ISBN 80-901105-3-8 [http://www.nm.cz/download/JML-18-2002-CBE.pdf PDF fulltext]
* (2003): Brown Fish Owl ("Bubo zeylonensis") in Europe: past distribution and taxonomic status. "Buteo" 13: 61-65. [http://www.nm.cz/download/JML-13-2003-bubo-zeylonensis.pdf PDF fulltext]
* (2002): A new "Ninox" owl from Sumba, Indonesia. "Emu" 102(3): 223-231. DOI|10.1071/MU02006 [http://www.uni-heidelberg.de/institute/fak14/ipmb/phazb/pdf-files/2002%20Pdf.Pubwink/17.2002.pdf PDF fulltext]
* (1985): The fossil record of birds. "In:" aut|Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): "Avian Biology" 8: 79-238. Academic Press, New York.
* (1994): New Information on the Late Pleistocene Birds from San Josecito Cave, Nuevo Leon, Mexico. "Condor" 96(3): 577-589. [http://elibrary.unm.edu/sora/Condor/files/DJVU/v096n03/P0577-P0589.djvu DjVu fulltext] [http://elibrary.unm.edu/sora/Condor/files/issues/v096n03/p0577-p0589.pdf PDF fulltext]