Burrowing owls are fascinating birds that live in underground burrows. But where do they go when not in their burrows? Let’s explore the migratory patterns and seasonal movements of these unique owls.
Do burrowing owls migrate?
Most populations of burrowing owls are migratory, meaning they move from one region to another with the seasons. However, some burrowing owl populations, particularly those in mild climates of Florida and California, are non-migratory and remain in the same burrows year-round.
Burrowing owls that live in northern climates, such as Canada and the northern United States, migrate south in the fall to escape the cold winter weather. They fly south to wintering grounds in Mexico and the southern United States. Some owls may travel over 1000 miles between their breeding and wintering grounds.
Spring migration north begins in March or April. Adult males tend to begin migrating first, followed by adult females and then juveniles. The owls fly at night and may cover 25-75 miles per night during migration. Their migrations seem to coincide with the movement of their primary prey – insects and small mammals.
Where do burrowing owls spend the winter?
Most burrowing owls that breed in Canada and the northern U.S. migrate south to wintering grounds in the southern U.S. and Mexico. Key wintering areas include:
- Southern California
- Southern Arizona
- Southern New Mexico
- Southern Texas
- Florida
- Central Mexico
In these regions, the owls find suitable habitat in grasslands, deserts, prairies, and agricultural areas. The temperate winter climate provides enough insect prey for the owls to survive until spring.
Do burrowing owls return to the same burrows every year?
In many cases, burrowing owls exhibit strong site fidelity, meaning they return to the same burrow sites year after year. One study in Saskatchewan found that over 75% of banded burrowing owls returned to within 200 meters of where they were banded the previous year.
However, burrowing owls may not return to the exact same burrow. Natural burrow systems often become damaged or collapse over time. Owls returning from migration often have to excavate new nesting burrows near their previous sites.
In Florida, where owls are non-migratory, the owls maintain and reuse the same burrow systems for many years. Here the mild climate prevents damage to unattended burrows.
Where do burrowing owls spend their summers?
During the summer breeding season, burrowing owls disperse across wide ranges of North America. Their breeding grounds extend from Canada south to Mexico. Key breeding areas include:
- Southern Canada (British Columbia, Saskatchewan, Manitoba)
- Northern U.S. plains and prairie states
- Western U.S. states
- Florida
- Northern Mexico
On these breeding grounds, burrowing owls nest in burrows located in open habitats like grasslands, prairies, deserts, and agricultural lands. They form monogamous breeding pairs and raise their young over the summer before migrating south again in the fall.
How far do burrowing owls disperse from their nests?
Burrowing owl young begin dispersing away from their nest burrows around 30 days after hatching. Initially the juveniles remain relatively close, within 330 feet (100 m) of their nest burrow.
But over time, they disperse farther distances. Juveniles have been recorded dispersing 1-12 miles (1.6-20 km) away from their natal burrow before migrating south in the fall. This dispersal of young owls helps maintain genetic diversity in the population.
Adult burrowing owls have smaller dispersal distances than juveniles. Adults may disperse up to 3 miles (5 km) between nesting attempts to find optimal burrow sites. But they often return to nest within 1 mile (1.6 km) of the previous year’s nest burrow.
How do burrowing owls locate new nesting burrows?
Burrowing owls don’t dig their own burrows – they rely on burrows created by other animals like prairie dogs, ground squirrels, and badgers. So how do they find new nesting burrow sites each year?
Studies show burrowing owls are attracted to burrows with fresh, blackened soil at the entrances. This indicates the burrows are actively maintained by resident mammals. The owls also prefer burrows on slight mounds with clear visibility all around – optimal for detecting predators.
During the breeding season, male owls perform aerial displays above potential nest sites. This flying behavior may help the owls evaluate burrow sites and signal ownership of a burrow.
Do burrowing owls have a home range?
Burrowing owls do inhabit home ranges centered around their nesting burrows, although the size of the home range can vary widely:
- Breeding season home ranges: 105 – 610 acres
- Non-breeding home ranges: 35 – 430 acres
- Wintering owls may use smaller home ranges around their roost burrows
Within their home ranges, the owls forage for prey like insects, small rodents, amphibians, and reptiles. They perch on fences, mounds, or other elevated points to hunt for prey.
As they deplete resources near one burrow, burrowing owls may relocate their central nesting burrow to a new area within their larger home range. This allows them to take advantage of other food sources.
How far do burrowing owls move each day?
Burrowing owls usually remain relatively close to their central burrow during the day. Foraging movements are often less than 1 mile (1.6 km) away.
However, burrowing owls are capable of longer distance hunting forays if needed. One study found the average maximum distance between nest burrows and owl locations was 2.4 miles (4 km).
At night, burrowing owls may also make longer dispersal flights when switching between burrow sites. Night movements up to 7 miles (12 km) have been recorded even when suitable burrows are available nearby.
Do burrowing owls return to nest in the same areas?
In many cases, burrowing owls exhibit high fidelity to previous nesting areas. However, nest site reuse can vary based on habitat quality:
- Higher reuse in high quality habitat with abundant burrows
- More nest shifting in degraded habitat as old burrows collapse
One Florida study found wintering owls returned to the same 10 acres (4 hectares) over 4 years. But in Saskatchewan, returning owls reused the same general area but switched burrow sites year to year.
While owls are loyal to nesting areas, dispersing juveniles help colonize new habitats and maintain genetic diversity.
How does weather impact burrowing owl movements?
Weather conditions directly influence burrowing owl activity levels and ranging behaviors:
- High winds – Owls remain in burrows during extremely windy conditions
- Heavy rain – Limits owl hunting due to reduced visibility and prey availability
- Cold winters – Trigger migration movements to southern regions
- Drought – May force larger owl movements if food becomes scarce
Owls conserve energy during harsh weather by remaining underground in their burrows. More favorable conditions allow them to extend their movements and foraging ranges.
How does prey availability impact movements?
Burrowing owl movements are strongly tied to the distribution and abundance of prey like insects, small mammals, and reptiles. Some patterns include:
- Larger home ranges in areas with lower prey density
- Further hunting distances when prey is scarce near main burrows
- Migration timed with movements of prey species like voles and grasshoppers
- High nest burrow reuse when local prey is consistently abundant
Areas with high prey density, such as prairie dog towns, support more sedentary owl populations with smaller home ranges. But scarcer prey requires wider-ranging owl movements.
Conclusion
In summary, burrowing owls are highly mobile birds that may migrate hundreds of miles between breeding and wintering grounds annually. Their movements are strongly influenced by weather, habitat quality, and prey availability. While owls often exhibit fidelity to previous nesting sites and areas, juveniles help disperse the population into new regions each year. Understanding burrowing owl ranging behaviors provides key insights into habitat requirements and conservation needs for these unique raptors.