Are Owls Mammals? Understanding Their Classification

Owls live in every part of the world except Antarctica and some remote islands. These large-eyed, nocturnal raptors are among the most mysterious, intriguing members of the animal kingdom. But are owls mammals?

These birds have thick, fluffy feathers and stand upright. For these reasons, people think they look more like a large, winged mammal as opposed to a bird. However, owls also lay eggs and can fly. Does this separate them from mammals? Let’s define mammals and owls to determine their proper classification.

What Defines a Mammal?

All mammals, with two odd exceptions, share these characteristics.

• They have a backbone that allows them to stand up straight.
• They give birth to live offspring.
• They are warm-blooded.
• Mammals are covered in hair or fur.
• They nurse their offspring.
• Mammals use their lungs to breathe.

The exceptions to this rule are the odd animals known as monotremes, who lay eggs but have all the other characteristics of mammals.

Owls have a backbone and use their lungs to breathe, but they don’t fit the other criteria of a mammal. They don’t nurse their young, have fur, or give birth to live offspring. Therefore, owls are not mammals; owls are birds.

What Defines a Bird?

What are the characteristics of birds? Here are the traits required to be classified as a bird.

• Feathers: These soft coverings evolved from scales. Some feathers are used for flight, and others are used for warmth and protection.
• Wings: Birds are not the only winged animals, but wings are an essential bird trait. All birds have wings, even those that don’t fly.
• Beak or bill: All birds have a beak or bill. The bill’s shape gives you clues about the bird’s diet and its abilities as a raptor.
• Eggs: All birds lay eggs. Eggs are not exclusive to birds. Other animals, including amphibians and fish, also lay eggs. Most birds build nests to shelter their eggs and offspring.
• Skeleton: Birds have a vertebra and a full skeleton. Birds that fly have hollow bones that keep them lightweight. Flightless birds, including penguins, have heavier bones.

How Do Owls Compare?

Here’s how they stack up when you look at bird characteristics.

• Feathers: All owls are covered in thick feathers. Owls use their feathers to keep warm and to fly.
• Wings: All owl species have wings. These fierce predators fly directly onto their prey.
• Beak: An owl’s beak is sharp and curved. It’s ideal for ripping and tearing meat.
• Eggs: Owls lay eggs and build nests.
• Skeleton: Like other flying birds, owls have hollow bones that allow them to get airborne easily.

It’s clear that the owl is a bird and not a mammal.

What Sets Owls Apart from Other Birds?

Despite sharing the major characteristics of their fellow birds, they have some key differences.

• Limited ability to move their eyes sideways: Owls have limited ability to move their eyes within their sockets, which is why they often move their heads to track objects.
• Asymmetrical ears: These raptors have excellent hearing. This is partly because of their irregularly placed ears, which are at different heights on their heads. This uneven placement allows them to hear the slightest sounds. This gives them an enormous advantage when hunting at night.
• Reversible toe: Some owls are zygodactyl, meaning they have two forward-facing and two backward-facing toes, while others have anisodactyl feet. This reversible toe gives them excellent footing and a strong grip on their prey.

How Many Kinds of Owls Are There?

There are over 250 species of owls. These birds inhabit forests and woodlands all over the world. Here are some noteworthy members of the family.

Nocturnal birds of prey, owls are divided into two categories: Tytonidae, which are barn owls with heart-shaped faces, and Strigidae, non-barn owls.

• Barn owl: One of the most common birds in the world, the barn owl stands out for its wide, white face and distinctive call. They feast on mice, rats, and other rodents, which is why they are welcome in barns all over the world. These birds mate for life.
• Snowy owl: This beautiful bird is one of the largest owl species. It is known for the pure white, fluffy feathers that keep it warm in the coldest temperatures. The snowy owl is most active at dawn and dusk. Snowy owls are apex predators in their environment.
• Long-eared owl: This large owl is known for its long ears that look even larger with their thick tufts of feathers. These owls live in the woods of North America, Europe, and parts of Africa. They feed on small animals and can live up to 30 years.