What Do Owls Eat? Owl Diet, Hunting and Pellets

What do owls eat most?

For most of the world’s more than 200 owl species, rodents and shrews are the main food. They are abundant, active at night and easy to swallow. In the barn owl, small mammals make up more than 90% of prey in temperate regions, and in Britain the field vole alone is the staple.

Because they depend so heavily on rodents, many owls follow rodent numbers. When voles boom, barn owls and short-eared owls lay larger clutches and barn owls may raise two broods; when voles crash, many young owls starve. Short-eared owls even wander long distances to settle where voles are plentiful. Foxes, weasels and kestrels compete for the same prey, as you can read in What do foxes eat?

What different owls eat

Owls range from the sparrow-sized elf owl to eagle-owls with a wingspan of more than 1.5 m (5 ft), so their prey varies enormously.

Some diets are remarkably narrow. In a study near Utqiaġvik, Alaska, lemmings made up almost all of more than 42,000 snowy owl prey items over 25 years. Others are remarkably broad: the great horned owl is one of the few regular predators of skunks.

How do owls hunt?

Most owls hunt from a perch. A tawny owl, for example, sits quietly on a branch, listens, then glides down to seize a mouse in its talons. Owls of open country, such as barn owls and short-eared owls, also hunt on the wing, quartering low over grassland and dropping onto prey.

Hearing is the owl’s great weapon. A dish-shaped facial disc funnels sound to the ears, and in barn owls, long-eared owls and several others the ear openings sit at different heights, which lets them pinpoint prey both sideways and vertically. Barn owls can catch mice in total darkness, and great gray owls can locate voles moving under about 60 cm (2 ft) of snow and plunge through to grab them.

Soft, fringed flight feathers make most owls almost silent, so prey hears little and the owl can keep listening as it attacks. Fish-eating owls lack these fringes, since fish cannot hear an owl approaching through the air. Smaller owls such as the elf owl catch insects in flight or pick them off flowers and foliage.

Do owls chew their food?

No. Owls have no teeth, so they swallow small prey whole, usually head first. Larger prey, such as a rabbit, is held in the talons and torn into pieces with the hooked bill.

Unlike hawks and many other birds, owls have no crop, a pouch in the throat for storing food. Prey goes straight to the stomach, which has two parts: the glandular proventriculus, where digestion begins, and the muscular gizzard. Owl stomach juices are less acidic than those of hawks and eagles, so bones survive almost intact. Owls often store extra prey at a roost and come back to it later.

What are owl pellets?

An owl pellet is a compact bundle of the parts an owl cannot digest: fur, bones, teeth, claws, feathers and the hard shells of insects. The gizzard squeezes these remains together within about six to ten hours of a meal, and the owl coughs the pellet back up through its mouth, usually at its daytime roost. Pellets are not droppings: an owl’s droppings are white, liquid splashes often called whitewash.

Pellets of larger owls are typically 2.5–5 cm (1–2 in) long. Their shape, size and color can help identify the owl that made them; barn owl pellets, for example, are usually dark and rounded. Pellets often pile up under favorite roosts in barns, church towers and old trees.

What owl pellets reveal

Because owls swallow small prey whole, their pellets are a near-complete record of what they ate. Skulls and lower jaws can be identified to species, so scientists use pellets to study owl diets without harming the birds and to map the small mammals of an area, including shy shrews and voles that are hard to trap.

Pellets have also turned up surprises, such as metal rings from small birds that had been banded earlier. Many schools dissect owl pellets in biology lessons; pellets sold for this are heat-sterilized, because untreated ones can carry bacteria such as Salmonella.

How much does an owl eat?

An adult barn owl eats the equivalent of one or more voles every night, about a quarter of its body weight. A snowy owl may need several lemmings a day. A food shortage of just a few nights can be fatal for small owls, which is one reason many of them live only a few years, as explained in How long do owls live?