Burrowing Owl: Profile and Information

The burrowing owl is a tiny, long-limbed owl that can be found across the open terrain of North and South America.

They can be seen in grasslands, deserts, agricultural areas, rangelands, or any other available dry region with low vegetation. 

They dwell in caves similar to those dug up by prairie dogs. 

Unlike most owls, burrowing owls are always enthusiastic during the day.

However, they sometimes show a tendency to avoid the midday heat.

Like many other species of owls, burrowing owls do most of their nighttime hunting, when they can use their night vision and hearing to their benefit.

As a result of their residing in open grasslands, burrowing owls have acquired longer limbs that allow them to run and fly while hunting.

Scientific classification

Physical Appearance

Burrowing owls possess colorful eyes, and their beaks could be grey or dark yellow, depending on the subspecies. They lack ear clumps and have a compressed facial disc.

The owls have notable white eyebrows and a white chin patch, which they can broaden and display during specific behaviors, including bobbing the head when irritated. 

Adult owls have brown heads and wings with noticeable spotting. The chest and abdomen are white with irregular brown barring, which also depends on the subspecies.

Young owls are comparable in appearance but lack the white spotting and brown barring feature. Young burrowing owls have a buff bar surrounding the upper wing, and their breasts may be buff-colored instead of white.

Male and female burrowing owls are comparable in size and appearance and exhibit slight sexual dimorphism.

Female burrowing owls are more prominent, while males tend to have more extended linear dimensions (tail length, wing length, and more).

Adult males seem brighter in color than females because they spend longer outside the burrow during the day, and their feathers fade.

The burrowing owl measures about 19 – 28 cm (7.5 – 11.0 in) in length, ranges 50.8 – 61 cm (20.0 – 24.0 in) across the wings, and weighs 140 – 240 g (4.9 – 8.5 oz).  As a size comparison, a typical adult is slightly bigger than an American robin (Turdus migratorius).

Taxonomic system

The burrowing owl is occasionally categorized in the monotypic genus Speotyto, centered on different karyotypes and morphology. 

Nevertheless, osteology and DNA sequence data indicate that the burrowing owl is a terrene member of the Athene little owls and is recognized as part of the genus class by most authorities.

A substantial number of subspecies were described, but they vary slightly in appearance, and the taxonomy of many needs to be validated.

Most subspecies are seen around the Andes and in the Antilles. Although they’re distinct, the relationship of the Florida subspecies to (and its distinctness from) the Caribbean birds is not entirely clear.

A paleosubspecies, A. c. providentiae, was discovered from fossil remnants in the Pleistocene of the Bahamas.

It’s still a mystery how these birds are associated with the existing A. c. floridana and whether they were amongst the ancestors of that subspecies.

It is also unclear if they symbolize a more distant species that completely vanished later.

Additionally, early fossils of identical owls have been recovered from several islands in the Caribbean, including Barbuda, Mona Island, Jamaica, the Cayman Islands, and Puerto Rico. 

These birds became extinct at the end of the Pleistocene. This could result from the ecological and sea-level changes toward the end of the last Ice Age.

These fossil owls vary in size from present-day burrowing owls, and their connection to the modern taxon has not been determined.

Habitat

Before European colonization, burrowing owls presumably occupied every favorable region of the New World. However, they have encountered some limitations during distribution in North America.

In some parts of South America, deforestation increases their scope.

The western burrowing owls are widespread in the Rocky Mountain Arsenal National Wildlife Refuge and some counties in Colorado.  They have also been stated to be in danger of extinction.

Burrowing owls span from the southern parts of the western Canadian districts through southern Mexico and western Central America.

They can also be discovered in Florida and several Caribbean islands.

In South America, they are scarce in the northwest and through the Andes but extensively dispersed from southern Brazil to Tierra del Fuego and Patagonia.

Burrowing owls that thrive in Canada and the northern U.S. often migrate to Mexico and the south of the U.S. during winter.

Ecology and Behaviour

Burrowing owls can live for at least nine years in the wild and over ten years in captivity.

Vehicles usually kill them while crossing roads and have several natural enemies, including coyotes, badgers, and snakes.

Burrowing owls are also killed by both domestic and wild cats & dogs.

Burrowing owls dwell in the holes dug by ground squirrels, a technique also utilized by rattlesnakes.

When the owl feels threatened, they retreat to the burrow and create hissing sounds identical to that of a rattlesnake.

The behavior is inferred to be an example of acoustic Batesian mimicry. It has been identified as an effective method against animals aware of rattlesnakes’ dangers.

Feeding

When owls hunt, they linger on a pole until they sight their prey. Then, they dive down on target or fly up to grab insects in flight.

Occasionally, they chase targets on foot. The highly flexible diet constitutes invertebrates and small vertebrates, comprising around one-third and two-thirds of their diet.

Burrowing owls mostly consume large insects and little rodents. However, burrowing owls rarely prey upon ground squirrels.

Unlike other owls, they also eat seeds and fruits, especially the fruit of tasajillo and other thorny pear and cholla cacti.

Reproduction

The breeding season of burrowing owls starts in late March or April in North America. They usually have only one mate, but sometimes, a male burrowing owl can have two mates. Pairs of owls often nest in relaxed territories, and their common breeding habitat is open grassland or prairie.

Nonetheless, they can sometimes adapt to other places, such as golf courses, airports, and agricultural fields.

Burrowing owls barely tolerate human presence, always nesting near farms, roads, homes, and adequately maintained irrigation canals.

During the mating season, burrowing owls will gather various materials to bind their nest, some of which are left all over the entrance to the burrow. The most popular material is mammal dung, usually from cows.

At some point, it was assumed that the waste helped mask the scent of the young owls, but scientists now believe that the manure helps regulate the microclimate inside the burrow and lure insects, which the owls can eat.

The female burrowing owl lays an egg every one or two days until she has completed a batch.

This batch typically includes 4 to 12 eggs. The female burrowing owl will incubate the eggs for about three to four weeks while the male gets her food.

After each egg has hatched, both parents are responsible for feeding their nestlings. After four weeks of hatching, the owlets can make brief flights and try leaving the nest burrow. However, the parents will support them for another one to three months.

Tract fidelity rates seem to differ among the populations of burrowing owls. In some locales, owls will often reuse a burrow for many years.

Owls in northern migratory populations are less inclined to return to the same nest yearly. Like many other birds, female owls are more likely to spread to various areas than male burrowing owls.

Countries like Canada, Mexico, Colorado, and Florida threaten the burrowing owls. It is widespread in open areas of many Neotropical states, where they occasionally occupy fields and parks in cities.

Farmers, as well as landowners, are encouraged not to disturb areas where burrowing owls reside. They are also urged to utilize alternative pesticides or lower amounts of these chemicals.

This will help preserve the existence of these birds for a more extended period.