1. Cannibals: Owls eat other owl species – especially those smaller than themselves
2. Big eyes: Owls’ eyes are extremely large and almost touch each other inside their heads
3. Predator: Owls are predators and therefore only eat meat. The only exception is the elf owl, which supplements its diet with fruits and seeds
4. Sounds: Although owls are well known for their distinctive owl sounds (an “owl-like” hoot), there are several species that make no sound at all. Some owl species also whistle
5. Silent killer: The ability of owls to hunt without being heard is one of their key hunting advantages. Owls’ plumage is specially adapted for silent hunting, enabling them to fly very close to their prey without being detected
6. Species: The owl order (Strigiformes) consists of 2 families: the owls proper (Strigidae) and the barn owls (Tytonidae). These families contain a number of genera and around 200 species in total
7. Female and male owls: Female owls are generally larger and heavier than male owls
8. Distribution: Owls live everywhere on Earth except Antarctica (South Pole)
9. Food: Although owls mostly eat small animals such as insects, mice, rats, birds, rabbits, etc. some of the larger species can hunt larger prey. Examples include: small monkeys, young warthogs, foxes, small deer, eagles and more. Some owls also feed primarily on fish
10. Classification: Although owls are often referred to as ‘birds of prey’, they are not related to birds of prey such as eagles, hawks or falcons. Although scientific classification is an ever-changing science, according to the so-called Sibly-Alquist model, owls are more closely related to hummingbirds, herons and songbirds (such as sparrows) than, for example, hawks

Fact: There are 2 owl families: the owls proper and the barn owls. The latter can be recognized by their heart-shaped faces

 

Largest and smallest owl species

• Smallest owl species: The smallest owl species in the world is the elf owl (Micrathene whitneyi), which can grow as small as 12.5 cm in length, have a wingspan of 27 cm and weigh 40 g
• Largest owl species: The largest owl species in Europe is the great horned owl (Bubo bubo). It is sometimes also given the title of the world’s largest owl, although the great horned owl (Bubo blakistoni) is generally slightly heavier and the barn owl (Strix nebulosa) is generally slightly longer.

 

Species (English)	Latin	Length (cm)	Wingspan (cm)	Weight (kg)
Eurasian eagle-owl	Bubo bubo	56 – 75	160 – 188	1,5 – 4,2
Blakiston’s fish owl	Bubo blakistoni	60 – 72	44,7 – 56	3,15 – 4,6
Great grey owl	Strix nebulosa	61 – 84	140 (average) – can be over 152	0,58 – 1,9

 

Fact: Owls hunt almost silently

 

The ability of owls to turn their heads

• 270 degrees: Owls can turn their heads 270 degrees. Although there are some humans who can turn their heads up to 180 degrees, it’s only possible for everyone else to turn their heads around 160 degrees
• Field of vision: The reason owls can turn their heads a full 270 degrees is because they can’t change their field of vision without moving their entire head and therefore rely on being able to move their head in many directions. Humans and many animals can turn their eyes and see in different directions thanks to a special eye muscle – but this muscle is not present in owls
• Neck vertebrae: In order to rotate their heads 270 degrees, owls have 14 neck vertebrae – which is a lot compared to the 7 neck vertebrae most other birds have
• Blood reserves: When owls turn their heads to extreme degrees, the blood supply to the head is cut off. Therefore, owls have special blood reserves that store blood for periods when the neck is turned to extreme degrees. Without these reserves, owls would faint every time they turned their head
• Blood vessels: The owls’ blood vessels have special bypasses and contain air sacs, both of which help prevent the blood vessels from bursting when the head is moved. Without the special blood vessels, owls would suffer a stroke every time they turned their head