This species is a rather slim and long winged owl with usually prominent erectile ear tufts, which are positioned closer to the center 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 grayish or brownish wash variably manifesting.
The base color 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 color 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 gray owl (Strix nebulosa).
On the underside, the body tends to be a somewhat paler ochraceous-tawny compared to the upperside.
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 colored (see subspecies) in the species, rimmed dusky often with white running down along the center 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 color while its eyes may vary from yellowish-orange to orange-red, tarsi and toes feathered.

The long-eared owl is a medium-sized owl, which measures between 31 and 40 cm (12 and 16 in) in total length.
Their wingspan is relatively large for their size, measuring 86 to 102 cm (2 ft 10 in to 3 ft 4 in).
However, compared to other widespread owls considered of medium size and to which they can appear broadly similar in size, such as barn owl (Tyto alba), short-eared owls and tawny owls (Strix aluco), the long-eared owl is quite a bit lighter and slenderer bodied, with mature weights around half of those of tawny owls not being uncommon.
As expected in owls and birds of prey in general, long-eared owls display reverse sexual dimorphism in which females are usually slightly larger than males (to the contrary of most non-raptorial birds).
Males furthermore may tend to be somewhat paler in plumage than females.
In Finland, one survey of the body mass of mature birds found that 22 males averaged 288 g (10.2 oz) while 20 females averaged 327 g (11.5 oz).
In body mass, European long-eared owls per a study were shown to run contrary to Bergmann's rule (that widespread animals should be smaller closer to the Equator) as body mass seemed to increase further south, being lightest in Sweden, where 37 males averaged 197 g (6.9 oz) and 24 females averaged 225 g (7.9 oz), intermediate in Denmark and heaviest in the Netherlands, where 21 males averaged 256 g (9.0 oz) and 24 females averaged 308 g (10.9 oz).
In migratory owls largely from Scandinavian summer grounds in England, the average weight of 8 males was 263.6 g (9.30 oz) and the average of 28 females was 294.7 g (10.40 oz).
Meanwhile, in various stud
This species is a rather slim and long winged owl with usually prominent erectile ear tufts, which are positioned closer to the center 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 grayish or brownish wash variably manifesting. The base color 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 color 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 gray owl (Strix nebulosa). On the underside, the body tends to be a somewhat paler ochraceous-tawny compared to the upperside. 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 colored (see subspecies) in the species, rimmed dusky often with white running down along the center 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 color while its eyes may vary from yellowish-orange to orange-red, tarsi and toes feathered.
The long-eared owl is a medium-sized owl, which measures between 31 and 40 cm (12 and 16 in) in total length. Their wingspan is relatively large for their size, measuring 86 to 102 cm (2 ft 10 in to 3 ft 4 in). However, compared to other widespread owls considered of medium size and to which they can appear broadly similar in size, such as barn owl (Tyto alba), short-eared owls and tawny owls (Strix aluco), the long-eared owl is quite a bit lighter and slenderer bodied, with mature weights around half of those of tawny owls not being uncommon. As expected in owls and birds of prey in general, long-eared owls display reverse sexual dimorphism in which females are usually slightly larger than males (to the contrary of most non-raptorial birds). Males furthermore may tend to be somewhat paler in plumage than females. In Finland, one survey of the body mass of mature birds found that 22 males averaged 288 g (10.2 oz) while 20 females averaged 327 g (11.5 oz). In body mass, European long-eared owls per a study were shown to run contrary to Bergmann's rule (that widespread animals should be smaller closer to the Equator) as body mass seemed to increase further south, being lightest in Sweden, where 37 males averaged 197 g (6.9 oz) and 24 females averaged 225 g (7.9 oz), intermediate in Denmark and heaviest in the Netherlands, where 21 males averaged 256 g (9.0 oz) and 24 females averaged 308 g (10.9 oz). In migratory owls largely from Scandinavian summer grounds in England, the average weight of 8 males was 263.6 g (9.30 oz) and the average of 28 females was 294.7 g (10.40 oz). Meanwhile, in various stud
Long-eared owl