Horned owls

Great Horned Owl Bubo virginianus

Scientific classification

Kingdom: Animalia Phylum: Chordata Class: Aves Order: Strigiformes Family: Strigidae Genus: Bubo Duméril, 1806

Species

See text

Synonyms

Nyctea Stephens, 1826 Ophthalmomegas Dejaut, 1911 and see text

 

The horned owls (America) and eagle-owls (Eurasia) are the genus Bubo, containing more than 20 species of typical owls which are found in many parts of the world. Horned owls are among the largest owls.

The species in taxonomic order are:

• 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 mackinderi - recently split form B. capensis
• Spotted Eagle-owl, Bubo africanus
• Grayish 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

mtDNA cytochrome b sequence data (Olsen et al. 2002) supports the decision to consider the Snowy Owl ("Nyctea" scandica) a specialised horned owl and moving it into Bubo:

• Snowy Owl, Bubo scandiacus

Similarly, the four fish-owls previously in the genus Ketupa were provisionally moved into Bubo too^{[citation needed}]:

• Blakiston's Fish-owl, Bubo blakistoni
• Brown Fish-owl, Bubo zeylonensis
• Tawny Fish-owl, Bubo flavipes
• Buffy Fish-owl, Bubo ketupu

However, the data of Olsen et al. (2002) suggests that to make the genus monophyletic, the Scotopelia fishing-owls would also need to be included in Bubo:

• Pel's Fishing-owl, Bubo peli
• Rufous Fishing-owl, Bubo ussheri
• Vermiculated Fishing-owl, Bubo bouvieri

On the other hand, the genus now becomes quite large and ill-defined. Another possibility, recognizing that Bubo in the expanded sense seems to consist of 2 clades, would be to unite the fish- and fishing-owls in Ketupa and move some aberrant Bubo species like the Barred Eagle-owl into this genus too (Olsen et al. 2002).

Fossil record

The supposed 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 strigid in the genus Minerva (formerly Protostrix). "Bubo" poirreiri from the Late Oligocene or Early Miocene of Saint-Gérard-le-Puy, France, is now placed in Mioglaux.

Named fossils retained in this genus are:

• Bubo florianae (Late Miocene of Csákvár, Hungary) - tentatively placed here
• Bubo binagadensis (Late Pleistocene of Binagady, Azerbaijan)

Undescribed fossils of prehistoric horned owls have been recovered from Late Pliocene deposits at Senèze, France (Lambrecht 1933:616), and from Late Pleistocene sediments of San Josecito Cavern, Mexico (Steadman et al. 1994). In addition, some paleosubspecies have been described. The Pleistocene Sinclair Owl from California, Bubo sinclairi, may be a paleosubspecies of the Great Horned Owl (Howard 1947), while Bubo insularis is probably 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 Strix (Feduccia 1970).

On the other hand, the supposed fossil heron "Ardea" lignitum (Late Pliocene of Germany) was apparently an owl and close to this genus or more probably actually belongs here (Olson 1985:167).

References

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

• Howard, Hildegarde (1947): A preliminary survey of trends in avian evolution from Pleistocene to recent time. Condor 49(1): 10-13. PDF fulltext

• Lambrecht, Kálmán (1933): Handbuch der Palaeornithologie. Gebrüder Bornträger, Berlin.

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

• Olsen, Jery; Wink, Michael; Sauer-Gürth, Heidi & Trost, Susan (2002): A new Ninox owl from Sumba, Indonesia. Emu 102(3): 223-231. DOI:10.1071/MU02006 PDF fulltext

• Olson, Storrs L. (1985): The fossil record of birds. In: Farner, D.S.; King, J.R. & Parkes, Kenneth C. (eds.): Avian Biology 8: 79-238. Academic Press, New York.

• Steadman, David W.; Arroyo-Cabrales, Joaquin; Johnson, Eileen & Guzman, A. Fabiola (1994): New Information on the Late Pleistocene Birds from San Josecito Cave, Nuevo Leon, Mexico. Condor 96(3): 577-589. PDF fulltext