''Strix'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

owl Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...

s in the typical owl family (Strigidae), one of the two generally accepted living families of owls, with the other being the

barn-owl Barn-owls (family Tytonidae) are one of the two families of owls, the other being the true owls or typical owls, Strigidae. They are medium to large owls with large heads and characteristic heart-shaped faces. They have long, strong legs with p ...

(Tytonidae). Common names are earless owls or wood owls, though they are not the only owls without ear tufts, and " wood owl" is also used as a more generic name for forest-dwelling owls.

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In bioge ...

birds in the genus '' Ciccaba'' are sometimes included in ''Strix''. These are medium-sized to large, robustly built, powerful owls. They do not have ear tufts and most are highly nocturnal woodland birds. Most prey on small mammals, birds, and reptiles. Most owls in the genus ''Strix'' can be distinguished from other genera of owls through their hooting vocalization and lack of visible ears. The

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

genus name ''Strix'' referred to a mythical vampiric owl-monster believed to suck the blood of infants. Although the genus ''Strix'' was established for the earless owls by

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in 1758, many applied the term to other owls (namely the ''

Tyto ''Tyto'' is a genus of birds consisting of true barn owls, grass owls and masked owls that collectively make up all the species within the subfamily Tytoninae of the barn owl family, Tytonidae. Taxonomy The genus ''Tyto'' was introduced in 1828 ...

'') until the late 19th century.Mlíkovský, Jirí (2002)
''Cenozoic Birds of the World, Part 1: Europe''
. Ninox Press, Prague. p.217 This genus is closely related to the extinct Ornimegalonyx.

Taxonomy

The genus ''Strix'' was introduced by the Swedish naturalist

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

in 1758 in the tenth edition of his '' Systema Naturae''. The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

is the

tawny owl The tawny owl (''Strix aluco''), also called the brown owl, is commonly found in woodlands across Europe to western Siberia, and has seven recognized subspecies. It is a stocky, medium-sized owl, whose underparts are pale with dark streaks, a ...

. The genus name is a

word meaning "owl".

Species

The genus contains 22 species: *

Spotted wood owl The spotted wood owl (''Strix seloputo'') is an owl of the earless owl genus, ''Strix''. Its range is disjunct; it occurs in many regions surrounding Borneo, but not on that island itself. Description The spotted wood owl grows to a length of ...

, ''S. seloputo'' *

Mottled wood owl The mottled wood owl (''Strix ocellata'') is a species of large owl found in India. They are found in gardens and thin deciduous forests adjacent to dry thorn forests or farmland. They are easily detected by their distinctive tremulous eerie cal ...

, ''S. ocellata'' *

Brown wood owl The brown wood owl (''Strix leptogrammica'') is found in India, Bangladesh, Sri Lanka, Indonesia, Taiwan, and south China. The brown wood owl is a resident breeder in south Asia. This species is a part of the family of owls known as typica ...

, ''S. leptogrammica'' *

Tawny owl The tawny owl (''Strix aluco''), also called the brown owl, is commonly found in woodlands across Europe to western Siberia, and has seven recognized subspecies. It is a stocky, medium-sized owl, whose underparts are pale with dark streaks, a ...

, ''S. aluco'' *

Maghreb owl The Maghreb owl (''Strix mauritanica'') is an owl of the earless owl genus, ''Strix''. It occurs in northwestern Africa from Morocco to Tunisia and Mauritania. It was previously considered a subspecies of the tawny owl. This species is a rat ...

, ''S. mauritanica'' * Himalayan owl, ''S. nivicolum'' * Desert owl, ''S. hadorami'' * Omani owl, ''S. butleri'' *

Spotted owl The spotted owl (''Strix occidentalis'') is a species of true owl. It is a resident species of old-growth forests in western North America, where it nests in tree hollows, old bird of prey nests, or rock crevices. Nests can be between high a ...

, ''S. occidentalis'' *

Barred owl The barred owl (''Strix varia''), also known as the northern barred owl, striped owl or, more informally, hoot owl, is a North American large species of owl. A member of the true owl family, Strigidae, they belong to the genus '' Strix'', whic ...

, ''S. varia'' * Cinereous owl, ''S. sartorii'' *

Fulvous owl The fulvous owl (''Strix fulvescens''), or Guatemala barred owl, is a resident of the cloud forests of Central America. A medium-sized true owl, it has a round head, lacking ear tufts. Typical coloration is warm dark brown or reddish brown on t ...

, ''S. fulvescens'' *

Rusty-barred owl The rusty-barred owl (''Strix hylophila'') is a medium-sized "typical owl" in subfamily Striginae. It is found in Argentina, Brazil (where it is known as the Brazilian owl), and Paraguay.HBW and BirdLife International (2020) ''Handbook of the B ...

, ''S. hylophila'' *

Chaco owl The Chaco owl (''Strix chacoensis'') is an owl found in Argentina, Bolivia, and Paraguay. Taxonomy and systematics The Chaco owl was originally described as a species, then quickly reclassified as a subspecies of rufous-legged owl (''Strix r ...

, ''S. chacoensis'' * Rufous-legged owl, ''S. rufipes'' * Ural owl, ''S. uralensis'' *

Great grey owl The great grey owl (''Strix nebulosa'') (also great gray owl in American English) is a very large owl, documented as the world's largest species of owl by length. It is distributed across the Northern Hemisphere, and it is the only species in th ...

, ''S. nebulosa'' * African wood owl, ''S. woodfordii'' *

Mottled owl The mottled owl (''Strix virgata'') is a medium-sized owl found in Central and South America from Mexico to Brazil and Argentina. The head and back are mottled brown and the underparts whitish, with vertical bars on the chest and throat. The eyes ...

, ''Strix virgata'' * Black-and-white owl, ''Strix nigrolineata'' * Black-banded owl, ''Strix huhula'' * Rufous-banded owl, ''Strix albitarsis''

Fossil species

The genus ''Strix'' is well represented in the

fossil record A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

. Being a fairly generic type of strigid owl, they were probably the first truly modern Strigidae to evolve. However, whether several of the species usually placed in this genus indeed belong here is uncertain. Generally accepted in ''Strix'' are: *''S. dakota'' (Early Miocene of South Dakota, USA) – tentatively placed here *''Strix'' sp. (Late Miocene of Nebraska, USA) *''Strix'' sp. (Late Pliocene of Rębielice Królewski, Poland) apparently similar to the

great grey owl The great grey owl (''Strix nebulosa'') (also great gray owl in American English) is a very large owl, documented as the world's largest species of owl by length. It is distributed across the Northern Hemisphere, and it is the only species in th ...

*''Strix intermedia'' (Early - Middle Pleistocene of EC Europe) – may be paleosubspecies of ''S. aluco'' *''Strix brea'' (Late Pleistocene of SW North America) Now placed in its own genus. (See below) * *''Strix'' sp. (Late Pleistocene of Ladds, USA) ''"Strix" wintershofensis'' (Early/Middle Miocene of Wintershof West, Germany) and ''"Strix" edwardsi'' (Middle Miocene of Grive-Saint-Alban, France), while being strigid owls, have not at present been reliably identified to genus; they might also belong into the European ''Ninox''-like group. ''"Strix" ignota'' (Middle Miocene of Sansan, France) is sometimes erroneously considered a '' nomen nudum'', but this assumption is based on what appears to be a ''

lapsus In philology, a lapsus (Latin for "lapse, slip, error") is an involuntary mistake made while writing or speaking. Investigations In 1895 an investigation into verbal slips was undertaken by a philologist and a psychologist, Rudolf Meringer and ...

'' or misprint in a 1912 source. It may well belong into the present genus, but this requires confirmation. ''"Strix" perpasta'' (Late Miocene – Early Pliocene of Gargano Peninsula, Italy) does not appear to belong into this genus either. It is sometimes considered a junior synonym of a brown fish-owl

paleosubspecies A chronospecies is a species derived from a sequential development pattern that involves continual and uniform changes from an extinct ancestral form on an evolutionary scale. The sequence of alterations eventually produces a population that is p ...

UMMP The University of Michigan in Ann Arbor is home to a number of museums. Located on the university's Central Campus are University of Michigan Museum of Natural History; the University of Michigan Museum of Art; the Kelsey Museum of Archaeology; Si ...

V31030, a

coracoid A coracoid (from Greek κόραξ, ''koraks'', raven) is a paired bone which is part of the shoulder assembly in all vertebrates except therian mammals (marsupials and placentals). In therian mammals (including humans), a coracoid process is prese ...

from Late Pliocene Rexroad Formation deposits of Kansas (USA), cannot be conclusively assigned to either the present genus or ''

Bubo A bubo (Greek βουβών, ''boubṓn'', 'groin') is adenitis or inflammation of the lymph nodes and is an example of reactive lymphadenopathy. Classification Buboes are a symptom of bubonic plague and occur as painful swellings in the thigh ...

''. Extinct forms formerly in ''Strix'': * ''"Strix" antiqua'' – now in '' Prosybris'' * ''"Strix" brea'' - now '' Oraristrix brea'' * ''"Strix" brevis'' – now in '' Intutula'' * ''"Strix" collongensis'' – now in '' Alasio'' * ''"Strix" melitensis'' and ''"Strix" sanctialbani'' – now in ''

'' * ''"Strix" murivora'' – male of the Rodrigues scops owl * ''"Strix" newtoni'' and ''"Strix" sauzieri'' – male and female of the Mauritius scops owl

Taxonomy

Species

Fossil species

References

Further reading