Asio


Asio is a genus of typical owls, or true owls, in the family Strigidae. The genus was introduced by the French zoologist Mathurin Jacques Brisson in 1760 with the long-eared owl as the type species. The genus name Asio is the Latin name for a type of eared owl, the feather tufts on the head of these owls give the appearance of "ears" which is a defining characteristic.
This group has representatives over most of the planet, and the short-eared owl is one of the most widespread of all bird species, breeding in Europe, Asia, North and South America, the Caribbean, Hawaii and the Galápagos Islands. Its geographic range extends to all continents except Antarctica and Australia.
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 years in search of better food supplies. Tropical Asio owls are largely sedentary. These owls hunt over open fields or grasslands, taking mainly rodents, other small mammals and some birds.
Asio owls are mainly nocturnal, but short-eared owls are also crepuscular. Most species nest on the ground, but the long-eared owl nests in the old stick nests of crows, ravens and magpies and various hawks.

Species

The genus contains the following species:
Two fossil species are recognized nowadays:
A further species of ancient giant predatory owls that lived in Ecuador about 40,000 years ago has been proposed in 2020: Asio ecuadoriensis. The supposed Late Eocene/Early Oligocene eared owl "Asio" henrici has been recognized as a member of the fossil barn-owl genus Selenornis. "Asio" pygmaeus cannot be assigned to a genus without restudy of the material. "Asio" collongensis is now placed in the genus Alasio.