The short-eared owl (Asio flammeus) is a medium-sized owl found throughout North America. Short-eared owls prefer open habitats like grasslands, prairies, meadows, and marshes. They are year-round residents in some parts of their range, while elsewhere they are migratory. Determining what states short-eared owls live in depends on whether the populations are resident or migratory.
Resident Populations
Some short-eared owl populations in the United States do not migrate and instead live year-round within the same state or region. States where year-round resident populations of short-eared owls are found include:
- California – Found year-round in suitable habitat throughout the state.
- Texas – Resident populations found across Texas.
- Louisiana – Year-round residents in coastal prairies and marshes.
- Florida – Resident in grasslands and marshes statewide.
- Hawaii – Introduced population on Oahu, Molokai, and Hawaii islands.
These resident owl populations may shift locally within their resident state or region depending on food availability, but they do not make substantial migratory movements out of the state. The presence of suitable year-round habitat allows them to find adequate food and shelter within the state.
Migratory Populations
In many parts of the short-eared owl’s range in North America, the owls are migratory. They breed during the summer in northern states and Canada before migrating south to overwinter in more southern states. During both their breeding season and wintering periods, migratory short-eared owls use habitat like grasslands, meadows, marshes, and agricultural areas.
Some of the key states used by migratory short-eared owls during breeding and migration include:
Breeding States
- Montana
- North Dakota
- South Dakota
- Minnesota
- Wisconsin
- Washington
- Oregon
During summer, millions of short-eared owls breed across the northern Great Plains, the Pacific Northwest, and other northern regions of North America. They nest on the ground, often relying on tall vegetation to help conceal the nest site.
Wintering States
- California
- Texas
- New Mexico
- Arizona
- Louisiana
- Florida
- South Carolina
In winter, short-eared owls that bred further north migrate south to find suitable habitat for the winter. Southern grasslands, agricultural areas, marshes, and coastal prairies attract wintering migrant short-eared owls. They often form loose flocks when hunting.
Migration Route States
During migration, short-eared owls pass through many states as they journey between their breeding and wintering grounds. Some states used as migration corridors include:
- North Dakota
- South Dakota
- Nebraska
- Kansas
- Oklahoma
- Colorado
- New Mexico
The Central Flyway through the Great Plains is an important migration route for many short-eared owls. But they can turn up throughout the continental U.S. during migration.
Year-Round Range
When both resident and migratory populations are taken into account, short-eared owls potentially live in the following states year-round:
- California
- Oregon
- Washington
- Idaho
- Nevada
- Utah
- Arizona
- Montana
- Wyoming
- Colorado
- New Mexico
- Texas
- Oklahoma
- Kansas
- Nebraska
- South Dakota
- North Dakota
- Minnesota
- Iowa
- Missouri
- Wisconsin
- Illinois
- Michigan
- Indiana
- Ohio
- Kentucky
- Tennessee
- Mississippi
- Alabama
- Georgia
- Florida
- South Carolina
- North Carolina
- Virginia
- West Virginia
- Maryland
- Delaware
- Pennsylvania
- New Jersey
- New York
- Connecticut
- Rhode Island
- Massachusetts
- Vermont
- New Hampshire
- Maine
So in summary, short-eared owls potentially live in almost every U.S. state at some point during the year when accounting for resident populations, migratory populations, and migratory pathways. The owls inhabit open country across the United States.
Favorite States and Regions
While short-eared owls have an extensive range across the United States, there are certain regions and states that seem to attract larger numbers of the owls:
- Florida – Has large wintering populations and year-round resident owls.
- Texas – Supports resident and wintering migrants across suitable habitat.
- Coastal California – Resident owls favor coastal prairies and marshes.
- Great Plains – Migration corridor and breeding grounds for many owls.
- Pacific Northwest – Important breeding area for the owls.
Though they live across most of the U.S., short-eared owls seem to thrive in warm grassland wintering areas and extensive northern grasslands and meadows used for nesting. Their populations appear to be greater in these favored regions and states.
Population Declines
Although short-eared owls once inhabited almost every U.S. state, their populations have declined substantially in recent decades. Causes include:
- Habitat loss as native grasslands and prairies diminished.
- Drainage of wetland areas.
- Intensive agriculture and conversion to cropland.
- Decline of prey species like voles and mice.
- Vehicle collisions during migration.
These declines mean short-eared owls are rare or completely absent across large portions of their former breeding range. Their wintering numbers have also decreased.
While they still inhabit most states, their populations are only robust in a handful of core areas. Greater conservation measures are needed to protect habitat and reduce other threats to short-eared owls.
Habitats Used
Short-eared owls use a variety of open habitats across their range in the United States:
Grasslands
Native prairies and grassland habitats provide prime areas for short-eared owls to nest and hunt. Both medium height and tall grass areas are utilized.
Marshes and Wetlands
Coastal salt and freshwater marshes attract owls, especially outside of breeding season. Inland wetlands are also occupied.
Agricultural Areas
Pastures, hayfields, and edges of croplands offer hunting areas for the owls. They often perch on fences and posts.
Airports
Some airports provide expansive grassy areas that mimic native habitat. Owl numbers have increased at some airports.
Dunes and Beaches
Coastal dunes, beaches, and shorelines are attractive to owls in coastal areas, providing open terrain.
Breeding
Short-eared owls nest on the ground in a scrape or depression, relying on grass and vegetation to conceal the site. Breeding occurs from March to July across their U.S. range. Peak activity is April to June.
Nest Sites
Short-eared owls show high fidelity to previous nesting sites and territories where they’ve bred successfully. They may reuse scrapes or create new ones nearby. Dense patches of grass or shrubs help hide the nest.
Clutch Size
Females usually lay 5-7 eggs per clutch. The eggs are white and sparsely spotted with brown markings. Incubation lasts 21-37 days.
Number of Broods
Short-eared owls are often double or even triple brooded during a breeding season. They may produce 2-3 successful broods per year in peak habitat. More food means more young.
Diet and Hunting
As a ground-nesting grasslands species, the diet and hunting habits of short-eared owls are specialized:
Diet
- Voles – Make up ≈50% of prey items.
- Mice – Frequently taken.
- Rats – Taken occasionally.
- Rabbits – Leverets and adults hunted.
- Small birds – Sparrows, larks and others.
- Large insects – Beetles, grasshoppers.
Their diet is dominated by small mammals like voles and mice. This availability influences habitat suitability.
Hunting
- Low flight over open habitat.
- Hover and plunge attacks on prey.
- Pounce on prey from perch.
- May cache extra prey items.
Short-eared owls are mostly crepuscular or diurnal hunters. Their distinctive low and buoyant flight helps them spot and catch prey.
Migration
The migration habits of short-eared owls include:
- Great Plains is a major fall and spring migration corridor.
- Central Flyway sees millions of owl migrants.
- Soaring, flapping flight during prolonged migration.
- Strong cold front winds facilitate migration.
- Migrates individually and in loose flocks.
- Young of the year first migrate south.
Weather patterns and prey abundance influence migration timing. Late October to November sees peak autumn migration.
Population Status
Short-eared owl populations have declined across large portions of North America:
Population Status | Trend |
---|---|
Global | Least Concern |
United States | Vulnerable/Declining |
Mexico | Threatened |
Canada | Secure |
While still widespread, habitat loss has caused steep declines across the U.S. range. Conservation efforts for owls focus on habitat protection and restoration.
Conservation Status
Several conservation designations apply to short-eared owls:
- Federal: Not listed under Endangered Species Act
- State: Listed as endangered in 11 northeastern states
- IUCN Red List: Least Concern
- Audubon: Vulnerable
- ABC: Yellow Watch List
Listings at the state level confer greater habitat protections for owls. Supporting national grassland conservation is also beneficial.
Conclusion
In conclusion, short-eared owls inhabit open country across almost all the lower 48 United States. They breed in northern grasslands and meadows before migrating south to overwinter. Formerly common, habitat loss has caused population declines across much of their U.S. range. Targeted conservation measures focusing on habitat protection can help safeguard short-eared owl populations into the future. With appropriate habitat, the owls could once again thrive across their wide-ranging North American distribution.