Owls are predatory birds belonging to the order Strigiformes. Strigiformes is a term used to identify 200 species of predatory birds which are mostly nocturnal and isolated, and the exceptions to this group are the northern hawk-owl and the burrowing owl. A group of owls is called a parliament.
Description of Appearance
The general description of an owl is: it has a flat face; its eyes are large and faces forward, with ear-holes. Each eye has a facial disk, a collection of feathers, surrounding the eye. The purpose of these feathers is to direct the sounds coming from various distances, into the asymmetrically places ear cavities.
The position of the eyes allows owls to have a greater sense of depth perception than most birds, and the position is necessary for hunting in low light. Since their eyes are fixed to their sockets, they have to turn their entire head to change their view. Owls have the ability to rotate their heads and necks at least up to 270 degrees.
Owls are farsighted, meaning; they are unable to see objects present very close to their eyes, like a few centimetres. However, their vision of objects presents farther away is exceptionally good. Female owls are larger in appearance than males, and the size difference varies across the species. One of the reasons, for this size difference, could be so that male owls can forage efficiently. The largest owl in this species is the Eurasian Eagle Owl, whose size is almost 75 centimetres. The smallest owl is the Pygmy owl, whose size is as small as 11 centimetres.
Also, know Why do owls hoot?
Some Facts about Owls
- Owls have the ability to survive in a variety of environments, from forests to deserts, and it depends on the species. Owls can make their nests in a variety of places, in the barks of trees, bushes, shrubs, and cactus, make holes in ground the, and even take up an abandoned nest.
- Owls’ diet consists of birds, rabbits, fish, mice, frogs, snakes, insects and squirrels.
- Owls have the ability to rotate their necks up to 270 degrees in both directions. They have three eyelids- a top lid, a bottom eyelid and a transparent membrane. This third membrane can move sideways and can cover the eye at an unbelievable speed. It helps to prevent damage to the eye.
- Owls’ have sensitive hearing. This ability helps them to find prey easily. The ears are located at the edge of their facial disk, and sounds are directed towards the feathers surrounding the facial disk. Also, the ear openings are placed in an asymmetrical manner, and in many species, one ear is slightly larger than the other, and place a little bit higher than the other ear. This system is very efficient as it allows locating and capturing any prey, just by hearing the sound of their movements. Interestingly owls do not have a sense of smell, similar to predatory birds like eagles and vultures.
- Not only their sense of hearing and sight helps in hunting, but they also have a feature called plumage. Plumage means the feathers that help in flying have fine, comb-like fringes that almost cut out the sound made when wings are moved. This gives an owl two advantages- preys cannot hear them coming and owls can use their hearing to listen for movements without getting interfered with by the sound of air made due to the rustling of feathers.
- Another interesting feature about the feathers of owls is that they help in camouflaging, as due to their colours and the way they are patterned.
- Owls are territorial, just like other birds. The males do not allow other male members near their nests, and only allow female members to enter the nest. The preference for the nest site depends on the species of owl. Owls mainly live in solitary almost throughout the year and mate in the spring season.
Are Owls Nocturnal?
Yes, the majority of owl species are nocturnal, meaning they are active during the night and sleep during the day, but there are some owls that are diurnal like the Northern Hawk Owl and the Northern Pygmy-Owl. Diurnal means, these owls are active during the day and sleep at night. Then there are some owls that are crepuscular like the Snowy Owls, meaning they are active during dusk and dawn, but sleep during the day.
These categories are based on generalizations. Owls can adapt themselves to the changing pattern of behaviour of their prey, as well adapt to the weather. If they are required to hunt during the day, they most surely can. Owls are not active during the day, because of the way their eyes are structured. Unlike human pupils, which can dilate to control the amount of light entering the eyes, an owl’s pupil cannot dilate or get smaller. Hence, they keep their eyes half-closed, which gives the illusion that they are sleeping.
The majority of owls stay active during the night. Why? As their vision and hearing are superb, it makes hunting at night almost effortless. All it takes for an owl to detect a slight movement of the prey and they know which direction the prey is moving. Also, nighttime brings out more prey for them, like rodents. Preys feel that nighttime is the perfect time for them to move, but it’s also the perfect time for owls to hunt. Their plumage makes their flying have almost no sound, so they are actually the perfect predators of the night.
Some owls that hunt during the night are the Long-Eared Owl and the Great Horned Owl. Long-Eared Owls have excellent camouflaging skills and can be considered the most nocturnal of all owls. They can be identified by their long, low hoot. Great Horned Owls, move at night, and can mainly be heard, not seen.
The main difference between nocturnal and diurnal owls is the timing. Nocturnal owls hunt during the night, diurnal owls hunt during the day and sleep at night and this difference in hunting can be attributed to a slight difference in their anatomy.