The long-eared owl (Asio otus), also known as the northern long-eared owl or, more informally, as the lesser horned owl or cat owl, is a medium-sized species of owl with an extensive breeding range. The scientific name is from Latin. The genus name Asio is a type of eared owl, and otus also refers to a small, eared owl. The species breeds in many areas through Europe and the Palearctic, as well as in North America. This species is a part of the larger grouping of owls known as typical owls, of the family Strigidae, which contains most extant species of owl (while the other taxonomic family of owls are the barn owls, or Tytonidae).
his species is a rather slim and long winged owl with usually prominent erectile ear tufts, which are positioned closer to the centre of the head than in many other types of owl. The purposes of ear tufts are not definitively known and are present in about half of living owls. Arguably the most popular theory amongst biologists and ornithologists is that ear tufts could be a means of intraspecies communication of intent and mood. In general coloration, the long-eared owl is often considered a hue of ochraceous-tawny with a greyish or brownish wash variably manifesting. The base colour is commonly overlaid with variable blackish vertical streaks (and occasionally spots), which are usually more apparent about the wings and back. The scapulars are usually marked whitish, which provide further contrast when seen against the base colour and blackish markings. The wing's dark carpal patches can also display broad panels of buff or almost orange on the wings across the base of primaries, which represent a more richly emphasized version of a pattern shared with other owls that tend to be vole-hunting specialists, like short-eared owls (Asio flammeus) and great grey owl (Strix nebulosa). On the underside, the body tends to be a somewhat paler ochraceous-tawny compared to the upper side. Long-eared owls tend to have dusky streaks on the upper breast, below which they may be heavily marked with herring bone pattern (which is created by dusky shaft-streaks and crossbars on these feathers). There is much individual and regional variation in markings with owls dwelling in more extensively forested regions tending to be of a darker hue, often so densely washed above as to appear largely dusky brown on the back and the underside largely overlaid with bolder dusky-blackish marks. Meanwhile, in some desert-like regions, the plumage may tend towards a somewhat more washed out look, at times appearing fairly cream or yellowish, with sparser and lighter dusky markings overall. The facial disc is visibly well developed and variably coloured (see subspecies) in the species, rimmed dusky often with white running down along the centre through the bill, while at times the white lines form a “moustache” and/or extending to the inside of the facial disc rim. The ear tufts are usually dusky in front and paler tawny on the back. Long-eared owl possess a blackish bill colourgre while its eyes may vary from yellowish-orange to orange-red, tarsi and toes feathered.