Barn-owl
Barn owls Temporal range:Late Eoceneto present
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Australian masked owl (Tyto novaehollandiae) | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Aves |
Order: | Strigiformes |
Family: | Tytonidae Ridgway,1914 |
Genera | |
Synonyms | |
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Barn-owls(familyTytonidae) are one of the twofamiliesofowls,the other being thetrue owlsor typical owls,Strigidae.They are medium to large owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerfultalons.They also differ from the Strigidae in structural details relating in particular to the sternum and feet.[1]
Barn-owls are a wide-ranging family, although they are absent from northern North America,SaharanAfrica, and large parts of Asia. They live in a wide range of habitats fromdesertstoforests,and fromtemperatelatitudes to thetropics.Within these habitats, they live near agricultural areas with high amounts of human activity.[2]The majority of the 20 living species of barn-owls are poorly known. Some, like thered owl,have barely been seen or studied since their discovery, in contrast to the common barn-owl, which is one of the best-known owl species in the world. However, some subspecies of the common barn-owl possibly deserve to be separate species, but are very poorly known.
Five species of barn-owl are threatened, and some island species wentextinctduring theHoloceneor earlier (e.g.,Tyto pollens,known from the fossil record ofAndros Islandin the Bahamas, and possibly the basis for the mythicalchickcharney).[3]Barn-owls are mostlynocturnaland generally non-migratory,living in pairs or singly.
Taxonomy and systematics
[edit]Barn-owls consist of two extant subfamilies: the Tytoninae orTytoowls (including the commonbarn owl) and thePhodilinaeor bay owls. The moderngeneraTytoandPhodilusare thought to have originated from a common ancestor from the Oligocene period.[4]It is believed the modern genusTytodescended from large nocturnal birds in the West Indies during the Quaternary. The systematics of this group began with the discovery ofTyto ostologa(now extinct), whose remains were found in north-central Haiti. This discovery led to the finding ofTyto pollens, Tyto noeli,andTyto riveroiin nearby cave deposits, all of which are now extinct and were also considered giant.[5][6]TheSibley-Ahlquist taxonomyunites theCaprimulgiformeswith the owlorder;here, barn-owls are asubfamily,Tytoninae. This is unsupported by more recent research (seeCypselomorphae), but the relationships of the owls in general are still unresolved.
Extant genera
[edit]Two extant genera are recognized:[7]
- GenusTyto– true barn-owls, grass owls and masked owls (17 species)
- GenusPhodilus–bay owls(2 species)
GenusTyto
[edit]Some of theTytospecies that exist include the common barn owl (Tyto alba), the American barn owl (Tyto furctata), the Australian barn owl (Tyto delicatula), and the Eastern Barn Owl (T. javanica). Within each of these species, there are many subspecies. Of the common barn owl there are 10 subspecies:T. alba affinis, T. alba alba, T. alba erlangeri, T. abla ernesti, T. alba gracilirostris, T. alba guttata, T. alba hypermetra, T. alba javanica, T. alba schmitzi,andT. alba stertens.Of the American barn owl, there are 5 subspecies:T. furcata attempta, T. furcata furcata, T. furcata hellmayri, T. furcata pratincola, and T. furcata tuidara.Of the Australian barn owl, there are 4 subspecies:T. delicatula delicatula, T. delicatula interposita, T. delicatula meeki,andT. delicatula sumbaensis.[8]
The common barn owl (T. alba) can be found in Africa and parts of Asia, including Eurasia. The American barn owl (T. furcata) can be found from North to South America. Lastly, the Australian barn owl (T. delicatula) can be found in Australia, New Zealand, Polynesia, and Asia.[4]
GenusPhodilus
[edit]This genus includes the Oriental bay owl (P. badius) and the Sri Lanka bay owl (P. assimilis).[4]The genus has a much smaller distribution thanTyto,with Oriental bay owls found in tropical Asia and Sri Lanka bay owls found in Sri Lanka and southwestern India.[9]
Extinct genera
[edit]Thefossil recordof barn-owls goes back to theEocene,with the family eventually losing ground to the true owls after the radiation ofrodentsand owls during theNeogeneepoch. Two subfamilies are known only from the fossil record: the Necrobyinae and the Selenornithinae. At least four extinct genera of barn-owls have been described:
- GenusNocturnavis(Late Eocene/Early Oligocene) – includesBubo incertus
- GenusNecrobyas(Late Eocene/Early Oligocene – Late Miocene, France) – includesBubo arvernensisandParatyto
- GenusSelenornis(Late Eocene/Early Oligocene of Quercy, France) – includesAsio henrici
- GenusProsybris(Late Eocene/Early Oligocene of Quercy(?) – Early Miocene of France and Austria)
Placement unresolved
[edit]- Tytonidae gen. et sp. indet. "TMT 164" (Middle Miocene of Grive-Saint-Alban, France) -Prosybris?
- GenusPalaeotyto(Late Eocene/Early Oligocene) from Quercy, France. Placement in this family is tentative, it may instead belong to the familySophiornithidae.
- GenusPalaeobyas(Late Eocene/Early Oligocene) from Quercy, France. Placement in this family is tentative, it may instead belong to the familySophiornithidae.
Former genera
[edit]The supposed "giant barn-owl"Basitytofrom the Early Eocene of Grafenmühle (Germany) was actually acrowned crane(Balearica);[10]the presumed "Easter Island barn-owl", based onsubfossilbones found onRapa Nui,has turned out to be aprocellarid;[11]and the specimen originally described as the fossilized PlioceneLechusa stirtoniwas later determined to be recent remains of a modern-day American barn owl.[12]
Description
[edit]The barn-owl's main characteristic is the heart-shapedfacial disc,formed by stifffeatherswhich serve to amplify and locate the source of sounds when hunting.[13]Further adaptations in the wing feathers eliminate sound caused by flying, aiding both the hearing of the owl listening for hidden prey and keeping the prey unaware of the owl. Barn-owls overall are darker on the back than the front, usually an orange-brown colour, the front being a paler version of the back or mottled, although considerable variation is seen even within species.
Bay owls closely resemble theTytoowls, but have a divided facial disc, ear tufts, and tend to be smaller.
References
[edit]- ^Bruce, M. D. (1999): Family Tytonidae (Barn-owls).In:del Hoyo, J.; Elliott, A. & Sargatal, J. (eds):Handbook of Birds of the WorldVolume 5: Barn-owls to Hummingbirds:34-75, plates 1-3. Lynx Edicions, Barcelona.ISBN8487334253
- ^Kross, Sara M.; Bourbour, Ryan P.; Martinico, Breanna L. (1 May 2016)."Agricultural land use, barn owl diet, and vertebrate pest control implications".Agriculture, Ecosystems & Environment.223:167–174.doi:10.1016/j.agee.2016.03.002.ISSN0167-8809.
- ^Marcot, Bruce G. (1995)."Owls of Old Forests of the World"(PDF).United States Department of Agriculture - Forest Service. p. 26.Retrieved6 March2019.
- ^abcUva, Vera; Päckert, Martin; Cibois, Alice; Fumagalli, Luca; Roulin, Alexandre (August 2018)."Comprehensive molecular phylogeny of barn owls and relatives (Family: Tytonidae), and their six major Pleistocene radiations".Molecular Phylogenetics and Evolution.125:127–137.doi:10.1016/j.ympev.2018.03.013.ISSN1055-7903.PMID29535030.
- ^Wetmore, Alexander (October 1937)."Bird Remains from Cave Deposits on Great Exuma Island in the Bahamas".Bulletin of the Museum of Comparative Zoology at Harvard College.80(12): 425–428.
- ^Arredondo, O (1972)."Especie nueva de lechuza gigante (Strigiformes: Tytonidae) del Pleistoceno cubano"(PDF).Boletín de la Sociedad Venezolana de Ciencias Naturales(in Spanish).
- ^Gill, Frank;Donsker, David, eds. (2017)."Owls".World Bird List Version 7.3.International Ornithologists' Union.Retrieved28 August2017.
- ^König, Claus; Friedhelm Weick; Michael Wink (2008).Owls of the world(2nd ed.). New Haven: Yale University Press.ISBN978-0-300-14227-3.OCLC639518017.
- ^del Hoyo, Josep; Collar, Nigel J. (2014).HBW and BirdLife International Illustrated Checklist of the Birds of the World.Vol. 1: Non-passerines. Barcelona, Spain: Lynx Edicions.ISBN978-84-96553-94-1.OCLC890655208.
- ^Mourer-Chauviré, Cécile (December 2001)."The systematic position of the genus Basityto, Mlikovsky 1998"(PDF).Proceedings of the Biological Society of Washington.114(4): 964–971.
- ^Steadman, David William (2006):Extinction and Biogeography of Tropical Pacific Islands Birds.University of Chicago Press.ISBN0-226-77142-3.
- ^Chandler, Robert M. (July–September 1982)."A Reevaluation of the Pliocene Owl Lechusa Stirtoni Miller"(PDF).Auk.99(3): 580–581.doi:10.1093/auk/99.3.580– via SORA.
- ^Grzimek, B.; Immelmann, K. (1977).Grzimek's Encyclopedia of Ethology.Van Nostrand Reinhold Company. p. 133.ISBN9780442229467.LCCN76009298.
External links
[edit]- Barn owlson the Internet Bird Collection