Owls are the one group of birds living a seclusive and mostly nocturnal life. This makes them had to find in nature and only a limited number of people regularly have contact with owls and are really interested in their life, habits, distribution and breeding. When I think of owls I think of birds with big heads, soft plumage, short tails, birds that can rotate their head by a maximum of 270° and birds with large eyes, usually surrounded by facial disks.
Some Basics on Owls
Basically, owls are birds of prey simply because they feed on prey. However, it is for their mainly nocturnal habits that they form their own order, separated from birds of prey. In the Western Palearctic, four species are diurnal which are Snowy Owl, Hawk Owl, Pygmy Owl and Short-eared Owl. They feed by catching prey and they all have binocular vision.
It is their binocular vision and binaural hearing which perfectly adapts owls to a life in twilight and during nighttime. Though, it must be mentioned that owls cannot see anything in total darkness. They compensate this by using their phenomenal hearing abilities. Owls have a number similarities they all share with each other:
- main activities during twilight and nighttime
- binocular vision
- hooked bill
- bill with cere
- facial disk
- circle of feathers around each eye
- excellent hearing
- large eyes are fixed in their sockets and cannot be moved
- ability to rotate the head by up to 270°, which compensates for fixed eyes
- large head often with characteristic face pattern
- dense plumage
- soft-surfaced plumage allows noiseless flight
- sharp curved claws
- sexes similar
- hunt from perch or out of search flight
Ear Tufts
Some owls sport ear tufts. Eagle Owl and Long-eared Owl do have the longest tufts. Short-eared Owl, Marsh Owl and Scops Owl have rather shortish ear tufts; other owls don’t have them at all.
What are ear tufts all about? Ear tufts are a pair of small feather bunches, constisting of 6-8 feathers, that can stund upright on the birds head or are draped alongside the forehead and over the eyebrows. These feather bunches are no real ears and mainly stand upright in case of agitation or emotions. The purpose of these feather ears is still unknown. Though, four theories have been developed in order to give some sense to that matter:
- Used as part of the camouflage
- it is part of the courtship display
- feather ears are raised in case of aggression
- it signals bird emotions such as anger, dominance and submission
Eye sizes of Owls
Owls have different eye sizes making them a good indicator to correctly identify the species. There are four different eye sizes which help identify the owl. Young owls already have the same eyes as adult owls:
- Eyes round and small: Pygmy Owl, Hawk Owl, Great Grey Owl
- Eyes almond-shaped and small: Barn Owl, Ural Owl
- Eyes large and round: Scops Owl, Tengmalm’s Owl, Little Owl, Long-eared Owl, Short-eared Owl, Tawny Owl, Eagle Owl
- cleft, large eyes: Snowy Owl
Iris Colours of the Owls
- Iris = blackbrown: Barn Owl, Tawny Owl, Ural Owl
- Iris = Yellow: Pygmy Owl, Scops Owl, Tengmalm’s Owl, Little Owl, Hawk Owl, Short-eared Owl, Great Grey Owl, Snowy Owl
- Iris = orange: Long-eared Owl, Eagle Owl
Taxonomy of the Owls in the Western Palearctic
There are 18 owl species existing in the Western Palearctic region. Some are limited to harsh subarctic conditions of northern Europe, some are native to northern Africa, some to the Middle East:
- Eurasian Eagle Owl (Bubo bubo) – most of Europe, nowadays even in urban areas
- Pharaoh Eagle Owl (Bubo ascalaphus) – North Africa, Egypt, Sinai, Middle East
- Brown Fish Owl (Bubo zyelonensis) – Southern Parts of Turkey, Middle East
- Great Grey Owl (Strix nebulosa) – Fennoscandia
- Ural Owl (Strix uralensis) – Fennoscandia, Baltics, North Russia and beyond Ural, Southeast Europe (the Balkans)
- Snowy Owl (Bubo scandicus) – North of Norway, Sweden, Finland and Russia
- (Northern) Hawk Owl (Surnia ulula) – Scandinavia
- Tengmalm’s Owl (Aegolius funereus) – most of Central Euroope, Alpine Range, Balkans, Black-Sea region, most of Scandinavia and northern Russia
- (Eurasian) Pygmy Owl (Glaucidium passerinum) – most of Scandinavia, northern Russia, parts of central Europe (North German Lowlands), Alpine region, Southeast Europe
- Long-eared Owl (Asio otus) – sedentary in most of Europe, migratory in Scandinavia and Russia
- Short-eared Owl (Asio flammeus) – migratory in Scandinavia, Russia, sedentary in the north of Black-Sea region, Iceland, Great Britain, across Europe and north Africa
- Marsh Owl (Asio capensis) – Northwest Africa
- Tawny Owl (Strix aluco) – most of Europe and north Africa, though not in middle and northern parts of Scandinavia
- Barn Owl (Tyto Alba) – most of Europe, north Africa eastern Mediterranean, absent from Scandinavia and eastern Europe
- Hume’s Owl (Strix butleri) – Sinai, Israel, Jordan
- Little Owl (Athene noctua) – most or Europe, north Africa, eastern Mediterranien, Middle East, around Black Sea, absent from Scandinavia and North Russia
- (Eurasian) Scops Owl (Otus scops) – Migratory in the southern parts of Europe and around Black Sea, sedentary in south Spain, Sicilly, Greece, wintering Africa
- Pallid Scops Owl (Otus brucei) – Middle East
