''Asio'' is a genus of typical owls, or true owls, in the family

Strigidae The true owls or typical owls (family (biology), family Strigidae) are one of the two generally accepted families of owls, the other being the barn owls and bay owls (Tytonidae). This large family comprises 230 living or recently extinct species ...

. This group has representatives over most of the planet, and the

short-eared owl The short-eared owl (''Asio flammeus'') is a widespread grassland species in the family Strigidae. Owls belonging to genus ''Asio'' are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or ...

is one of the most widespread of all bird species, breeding in

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

North North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating Direction (geometry), direction or geography. Etymology T ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

, the

Caribbean The Caribbean ( , ; ; ; ) is a region in the middle of the Americas centered around the Caribbean Sea in the Atlantic Ocean, North Atlantic Ocean, mostly overlapping with the West Indies. Bordered by North America to the north, Central America ...

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

and the

Galápagos Islands The Galápagos Islands () are an archipelago of volcanic islands in the Eastern Pacific, located around the equator, west of the mainland of South America. They form the Galápagos Province of the Republic of Ecuador, with a population of sli ...

. Its geographic range extends to all continents except

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean (also known as the Antarctic Ocean), it contains the geographic South Pole. ...

and

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. These are medium-sized owls, in length with wingspans. They are long-winged and have the characteristic facial disc. The two northern species are partially migratory, moving south in winter from the northern parts of their range, or wandering nomadically in poor

vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...

years in search of better food supplies. Tropical ''Asio'' owls are largely sedentary. These owls hunt over open fields or grasslands, taking mainly

rodent Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...

s, other small

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s and some

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s. ''Asio'' owls are mainly

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

, but short-eared owls are also

crepuscular In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal (active during dawn), vespertine (biology), vespertine/vespertinal (active during dusk), or both. This is distinguished from diurnalit ...

. Most species nest on the ground, but the long-eared owl ('' Asio otus'') nests in the old stick nests of

crow A crow is a bird of the genus ''Corvus'', or more broadly, a synonym for all of ''Corvus''. The word "crow" is used as part of the common name of many species. The related term "raven" is not linked scientifically to any certain trait but is rathe ...

s, ravens and magpies (family

Corvidae Corvidae is a Cosmopolitan distribution, cosmopolitan Family (biology), family of Songbird, oscine passerine birds that contains the crows, ravens, Rook (bird), rooks, magpies, jackdaws, jays, treepies, choughs, and Nutcracker (bird), nutcrackers ...

) and various hawks.

Taxonomy

The

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

''Asio'' was introduced by the French zoologist

Mathurin Jacques Brisson Mathurin Jacques Brisson (; 30 April 1723 – 23 June 1806) was a French zoologist and natural philosophy, natural philosopher. Brisson was born on 30 April 1723 at Fontenay-le-Comte in the Vendée department of western France. Note that page 14 ...

in 1760 with the long-eared owl (''Asio otus'') as the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

. The genus name is from ''asiō'', the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

name used by

Pliny the Younger Gaius Plinius Caecilius Secundus (born Gaius Caecilius or Gaius Caecilius Cilo; 61 – ), better known in English as Pliny the Younger ( ), was a lawyer, author, and magistrate of Ancient Rome. Pliny's uncle, Pliny the Elder, helped raise and e ...

for a type of horned owl, the feather tufts on the head of these owls give the appearance of "ears" which is a defining characteristic.

Species

The genus contains the following nine species: Three

fossil 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 preserve ...

species are recognized: * ''Asio brevipes'' (Glenns Ferry Late Pliocene of Hagerman, USA) * ''Asio priscus'' (Late Pleistocene of San Miguel Island and Santa Rosa Island, USA) * '' Asio ecuadoriensis'' (Late Pleistocene of Ecuador)Lo Coco, G.E., Agnolín, F.L. & Román Carrión, J.L.
Late Pleistocene owls (Aves, Strigiformes) from Ecuador, with the description of a new species
In: J Ornithol 161, pp 713–721; March 5, 2020; doi:10.1007/s10336-020-01756-x The supposed Late Eocene/Early Oligocene eared owl ''"Asio" henrici'' has been recognized as a member of the fossil

barn-owl The barn owls, owls in the genus ''Tyto'', are the most Cosmopolitan distribution, widely distributed genus of owls in the world. They are medium-sized owls with large heads and characteristic heart-shaped faces. They have long, strong legs with ...

genus ''Selenornis''. ''"Asio" pygmaeus'' (often misspelt ''pigmaeus'') cannot be assigned to a genus without restudy of the material. ''"Asio" collongensis'' (Middle Miocene of Vieux-Collonges, France) is now placed in the genus ''Alasio''.Mlíkovský, Jirí (2002):
Cenozoic Birds of the World, Part 1: Europe
''. Ninox Press, Prague.

References

{{Authority control Bird genera