Burrowing Owl

## Description

The burrowing owl (Athene cunicularia ) is a small, long-legged owl found throughout open landscapes of North and South America. Burrowing owls can be found in grasslands, rangelands, agricultural areas, deserts, or any other open, dry area with low vegetation. They nest and roost in burrows, such as those excavated by prairie dogs (Cynomys spp.). Unlike most owls, burrowing owls are often active during the day, although they tend to avoid the midday heat. Like many other kinds of owls, though, burrowing owls do most of their hunting during dusk and dawn, when they can use their night vision and hearing to their advantage. Living in open grasslands as opposed to forests, the burrowing owl has developed longer legs that enable it to sprint, as well as fly, when hunting.

## Appearance

Burrowing owls are small, long-legged birds of prey found throughout open terrains of North and South America. They have bright eyes and their beaks can be dark yellow or gray depending on the subspecies. They have prominent white eyebrows and a white "chin" patch which they expand and display during certain behaviors, such as a bobbing of the head when agitated. Adults have brown heads and wings with white spotting. The chest and abdomen are white with variable brown spotting or barring, also depending on the subspecies. Juvenile owls are similar in appearance, but they lack most of the white spotting above and brown barring below; their breast may be buff-colored rather than white. Living in open grasslands as opposed to forests, Burrowing owls have developed longer legs that enable them to sprint, as well as fly, when hunting.

## Distribution

Burrowing owls range from the southern portions of the western Canadian provinces through southern Mexico and western Central America. They are also found in Florida and many Caribbean islands. In South America, they are patchy in the northwest and through the Andes, but widely distributed from southern Brazil to Patagonia and Tierra del Fuego. Burrowing owls are year-round residents in most of their range. Birds that breed in Canada and the northern U.S. usually migrate south to Mexico and the southern U.S. during winter months. These owls inhabit grasslands, rangelands, agricultural areas, deserts, or any other open dry area with low vegetation.

## Behavior

Burrowing owls spend most of their time on the ground, and may breed in loose colonies. They nest and roost in burrows, such as those excavated by prairie dogs. Unlike most owls, Burrowing owls are often active during the day, although they tend to avoid the midday heat. However, most of their hunting is done from dusk until dawn, when they can use their night vision and hearing to their advantage. When hunting, Burrowing owls wait on a perch patiently until they spot prey. Then, they swoop down on prey or fly up to catch insects in flight. Sometimes, they walk, hop, or chase prey on foot across the ground. When not hunting Burrowing owls sleep at their burrow entrances or on depressions in the ground. The rest of the time is spent stretching, preening, bathing in a puddle and the birds will also take a dust bath in a shallow depression in the dirt. Disturbed Burrowing owls bob jerkily up and down and can scream, cluck and chatter when defending the nest. Their main call is a mellow 'coo-coooo' and a song 'co-hoo' that can usually be heard at night.

## Diet

Burrowing owls are carnivores. They mainly feed on large insects and small rodents but also amphibians, reptiles, and birds. Unlike other owls, they also eat some fruits and seeds.

## Reproduction

Burrowing owls are monogamous; pairs may stay together for one breeding season or mate for life. Occasionally males may be polygynous and have two mates. The breeding season begins in late March or April in North America. Burrowing owls sometimes nest in loose colonies in open grassland or prairie, but may occasionally adapt to other open areas like airports, golf courses, and agricultural fields. They also often nest near roads, farms, homes, and regularly maintained irrigation canals. The nest is located in a burrow; if burrows are unavailable and the soil is not hard or rocky, the owls may excavate their own. The female will lay a clutch, which can consist of 4 to 12 eggs (usually 9). She will then incubate the eggs for 3 to 4 weeks while the male brings her food. After the eggs hatch, both parents will feed the young. Four weeks after hatching, the owlets can make short flights and begin leaving the nest burrow. The parents will still help feed their young for 1 to 3 months until they are ready to hunt their own meals.

## Population

### Population threats

Burrowing owls are common and widespread in open regions of many countries in Central and South America. However, these birds are endangered in Canada and threatened in Mexico. They are a state threatened species in Colorado and Florida. The major reasons for declining populations in North America are control programs for prairie dogs and loss of habitat. Other important threats include collisions with vehicles when crossing roads, the use of pesticides, shooting, and predation by feral and domestic cats, dogs, coyotes, and snakes.

### Population number

According to the All About Birds resource the total breeding population size of the Burrowing owl is around 2 million individuals. According to the Defenders of Wildlife resource the total population size of the species is less than 10,000 breeding pairs. Overall, currently Burrowing owls are classified as Least Concern (LC) on the IUCN Red List but their numbers today are decreasing.

### Ecological niche

Burrowing owls control populations of small mammals and insects that they consume in their diet. In turn, these little owls also serve as a food item for some local predators.

## Fun Facts

Male and female Burrowing owls are similar in size and appearance. Males, however, appear lighter in color than females because they spend more time outside the burrow during daylight, and their feathers become "sun-bleached".

Burrowing owls have a binocular vision that allows them to see in a radius of 110 degrees. They can also rotate their head 270 degrees in each direction.

Burrowing owls like to decorate their nests. During the nesting season, they collect a wide variety of materials to line their nest, some of which are left around the entrance to the burrow. The most common material is mammal dung, usually from cattle. At one time it was thought that the dung helped to mask the scent of the juvenile owls, but researchers now believe the dung helps to control the microclimate inside the burrow and to attract insects, which the owls may eat.

When feeling danger, Burrowing owls hide in their burrow and produce rattling and hissing sounds similar to that of a rattlesnake. This is a very effective strategy against animals that are familiar with dangers posed by rattlesnakes.

These small hunters sometimes catch more prey than they can eat and store remained food in their burrows for later.

Cowboys sometimes called Burrowing owls "howdy birds"; it seemed to them that these tiny birds were nodding in greeting at the entrances of their burrows. In fact, Burrowing owls do that when they are disturbed.