Owls

Common Name:

Owls

Scientific Name:

Strigiformes

Diet:

Carnivore

Average Life Span In The Wild:

5 to 12 years

Size:

5 to 28 inches

Weight:

1.5 ounces to 9 pounds

Owls can be found in nearly every environment in the world, from deserts to coniferous forests to the Arctic tundra. All of the roughly 250 owl species live aboveground except for one: the burrowing owl, a small owl found in North and South America that nests in abandoned holes dug by other animals. 

Part of a group of birds called Strigiformes, owls are divided into two families: Tytonidae, which includes the dozen-plus species of barn owls, the most widespread of all land birds; and Strigidae, comprising all other species. Owls have stocky bodies, and they all have round faces except for some species of Tytonidae, such as barn owls, which have heart-shaped faces. 

Species vary by size, pattern, and coloration, but every owl has two features distinct to raptors: sharp talons and hooked beaks. These and other adaptations help them hunt animals with incredible skill and efficiency, similar to hawks, eagles, and other birds of prey.

Diet and hunting style

Most owls eat mainly small rodents, but their diets also include birds, fish, insects, and larger creatures like young deer and foxes. Some owls hunt during the day or at dusk, but the majority pursue prey at night, aided by their ultra-sensitive hearing and excellent night vision. Owls have a trait called eyeshine—their eyes glow orange-red when illuminated at night. The glow is caused by a layer of tissue behind their retinas that reflects visible light, giving them extraordinary ability to see in the darkness. Although they can’t move their large eyes, they make up for their lack of ocular musculature with necks that can twist up to 270 degrees to track the movement of prey.

Most owls scan for prey from their perches or while mid-air, but some will hover like a helicopter above their victims. Because the edges of owl feathers are soft instead of stiff, the carnivores have an advantage over their targets: a silent swoop. 

Toothless like other birds, owls swallow their victims whole or in large chunks. They later cough up pellets of indigestible hair and bones.

Mating and other behavior

After a hunting session, owls return to a place to rest, called a roost. Barn owls typically roost on roof timbers or inside tree cavities, while other species prefer to perch on shady tree branches near their hunting grounds. The majority of owl species roost by themselves and may attempt to scare off intruders by hissing or spreading their wings to appear larger. 

Male owls initiate the mating process, most often in winter, by calling out to females in vocalizations that vary from deep hoots to high-pitched shrieks, depending on the species. After a female responds with her own calls, the male begins an elaborate wooing session: gifts of food, chest-fluffing, and spectacular aerial dances. 

Most owls pair with the same mate at least once a year to breed, while pairs from some species, such tawny owls and little owls, remain together throughout the year.

Reproduction and family life

Owls lay up to 14 eggs per brood, depending on the species and the availability of food. Parents protect their babies, called owlets or nestlings, in a tree cavity or nest built and abandoned by other birds such as hawks and crows. Only the short-eared owl and the iconic snowy owl build their own nests, which they often construct by scraping dirt into a hollow in the ground at a high point such as the top of a mound, to allow them to keep watch for for predators.

Parents work together to raise their young. The male delivers food to the female, who tears it up for the little ones. Owlets begin exploring outside the nest after seven to 12 weeks, depending on the species, and permanently go off on their own a few weeks later. 

Threats

Owl numbers have shrunk around the world as humans destroy their habitat for agriculture and development, forcing the animals to compete for food in tighter spaces. Other common threats include hunting, dwindling food sources as climate change impacts prey populations, and the ingestion of poisoned animals such as rats and mice.

Most owl species aren’t under immediate threat of extinction, but the International Union for Conservation of Nature does list at least a dozen species as endangered or critically endangered. These include a handful of island-dwelling owls and the world’s largest, the Blakiston’s fish owl, found throughout Russia and parts of Asia. Fewer than 2,000 of these fire-hydrant-size owls remain.