Burrowing Owl

Burrowing Owl

Other Names

• Mochuelo de Madriguera (Spanish)
• Chevêche des terriers (French)

Basic Description

Owls are unmistakable birds, and that goes double for a long-legged owl that hunts on the ground during the day. Burrowing Owls are small, sandy colored owls with bright-yellow eyes. They live underground in burrows they’ve dug themselves or taken over from a prairie dog, ground squirrel, or tortoise. They live in grasslands, deserts, and other open habitats, where they hunt mainly insects and rodents. Their numbers have declined sharply with human alteration of their habitat and the decline of prairie dogs and ground squirrels.

 

Cool Facts:

• Unlike most owls in which the female is larger than the male, the sexes of the Burrowing Owl are the same size.
• Burrowing Owls often stow extra food to ensure an adequate supply during incubation and brooding. When food is plentiful, the birds' underground larders can reach prodigious sizes. One cache observed in Saskatchewan in 1997 contained more than 200 rodents.
• In the absence of suitable homes created by ground squirrels, prairie dogs, desert tortoises, or other burrowing animals, Burrowing Owls have been known to nest in piles of PVC pipe and other lairs unintentionally provided by humans. Conservationists make use of the owls' adaptability by supplying artificial burrows made of buckets, pipes, tubing, and other human-made materials.
• Burrowing Owls have a higher tolerance for carbon dioxide than other birds—an adaptation found in other burrowing animals, which spend long periods underground, where the gas can accumulate to higher levels than found above ground.
• Efforts to protect Burrowing Owl populations can turn into complex ecological juggling acts. On a naval base near San Diego, California, land managers had to balance the needs of declining Burrowing Owls with a colony of endangered Least Terns, whose chicks the owls sometimes preyed upon.
• Before laying eggs, Burrowing Owls carpet the entrances to their homes with animal dung, which attracts dung beetles and other insects that the owls then catch and eat. They may also collect bottle caps, metal foil, cigarette butts, paper scraps, and other bits of trash at the entrance, possibly signifying that the burrow is occupied.
• The oldest known Burrowing Owl was at least 9 years, 11 months old when it was sighted in California in 2014.

 

Habitat:

Burrowing Owls live in open, treeless areas with low, sparse vegetation, usually on gently sloping terrain. The owls can be found in grasslands, deserts, and steppe environments; on golf courses, pastures, agricultural fields, airport medians, and road embankments; in cemeteries and urban vacant lots. They are often associated with high densities of burrowing mammals such as prairie dogs, ground squirrels, and tortoises. Breeding pairs stay near a dedicated nesting burrow, while wintering owls may move around and may roost in tufts of vegetation rather than in burrows

Food:

Burrowing Owls eat invertebrates and small vertebrates, including lizards, birds, and mammals. Invertebrates, especially insects, constitute the majority of food items, while vertebrates make up the bulk of the diet by mass. Burrowing Owls commonly hunt grasshoppers, crickets, moths, beetles, mice, voles, and shrews. They also prey on dragonflies, giant water bugs, earwigs, caterpillars, scorpions, and earthworms, frogs, toads, snakes, lizards, turtles,and salamanders, bats, ground squirrels, small weasels, young rabbits, songbirds, waterbirds, baby ducks, and even young burrowing owls. Females catch more insects, mostly during the day; males take most of the vertebrates, mostly at night.

Behavior:

Burrowing Owls hunt at all hours of the day and night. Usually staying close to the ground, they fly, hover, walk, or run, seizing prey in their talons. Between forays for food, they sleep on dirt mounds at their burrow entrances or on depressions in the ground. Disturbed owls bob jerkily up and down, as do hunting owls pinpointing prey. They are mostly monogamous and breed close together in loose colonies. Females stay in or near the nest burrow until chicks fledge, while males tend to stand guard at a nearby burrow or perch. Males defend their territories against other males by vocalizing, displaying in a weaving crouch with feathers fluffed, or chasing and attacking with outstretched talons. Courting adults—mainly males—display by circling overhead or flying dozens of feet into the air, hovering for a few seconds and then rapidly descending. Pairs vocalize, rub bills, and preen, the male calling and presenting food to the female. Young owls play-hunt by jumping on each other, on prey brought by their parents, and on dung around the burrow.

 

Data Source: allaboutbirds