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Asio flammeus

Short-eared Owl


Asio flammeus

(Pontoppidan, E, 1763)
Lechuzón Campestre
Mocho-dos-banhados

Family: Strigidae
Order: Strigiformes
Class: Aves
Phylum / Division: Chordata
Kingdom: Animalia

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Records from Casilda


Description


Possesses a highly specialized anatomy and behavior optimized for hunting across wide-open landscapes. This medium-sized owl measures 34 to 43 centimeters (13 to 17 inches) in length, boasts a wingspan of 85 to 110 centimeters (33 to 43 inches), and weighs between 206 and 475 grams (7.3 to 16.8 ounces), with females being slightly larger than males. Its dorsal plumage is intricately mottled with shades of brown, buff, and cream, providing superb camouflage against dead grass, while the underparts are pale sand-colored with bold, dark brown vertical streaking. The distinct grayish-white facial disc is punctuated by dark rings outlining intense, yellow eyes, and it features tiny, often invisible ear tufts situated near the center of the forehead, which are raised only when the bird is in a defensive posture.

Geographical distribution: Holds one of the most extensive cosmopolitan distributions of any bird of prey, inhabiting every continent except Antarctica and Australia. It breeds extensively across the subarctic and temperate zones of North America and Eurasia, with isolated resident populations occurring in South America, including the high-altitude Andes, the Southern Cone, and remote islands such as the Galapagos Islands and the Hawaiian archipelago. Northern populations are highly migratory, wintering southwards into Central America, North Africa, and southern Asia, often exhibiting nomadic movements tied closely to fluctuating prey populations.

Habitat: Shows a strict affinity for vast, open biomes devoid of dense tree canopies. It is commonly found in temperate grasslands, arctic tundras, savannas, peatlands, salt marshes, and freshwater wetlands. In addition, it readily occupies agricultural fallow fields, young forestry plantations, and coastal sand dunes, requiring expansive areas of low to moderate vegetation cover that provide both suitable ground cover for nesting and unobstructed lines of sight for foraging.

Feeding: Functions as an obligate predator primarily focused on microtine rodents. Voles and field mice comprise the vast majority of its diet, though it dynamically shifts to other prey such as shrews, pocket gophers, young rabbits, and occasionally songbirds or large insects when primary rodent populations crash. Hunting occurs via low-altitude quartering flights, where the raptor glides silently just meters above the ground, relying on its asymmetrical ear openings and keen eyesight to pinpoint the rustle of prey beneath the vegetation.

Behavior: Departs from typical strigid patterns by being remarkably diurnal and crepuscular, frequently observed active during late afternoons and early mornings. Its flight is uniquely buoyant, erratic, and moth-like, characterized by deep, slow wingbeats. During the non-breeding season, it exhibits a rare communal social structure, forming winter roosts of up to dozens of birds in areas with high rodent densities; however, during the breeding season, males perform spectacular aerial courtship displays, executing steep dives and producing rapid wing-clapping sounds to advertise territory.

Nesting: Represents a unique exception among owls by constructing its own nest directly on the ground. The female scrapes a shallow bowl in the soil, hidden by dense grasses or shrubs, and lines it with dry grass, weeds, and down feathers plucked from her chest. Clutch size is highly responsive to food availability, ranging from 4 to 9 white eggs, though massive rodent outbreaks can trigger exceptional clutches of up to 14 eggs. Incubation is performed solely by the female for 21 to 29 days, starting with the first egg, which leads to highly asynchronous hatching and a pronounced size hierarchy among the chicks.

Conservation status: Listed globally as Least Concern (LC) on the IUCN Red List due to its expansive range. Nonetheless, localized and regional populations are experiencing severe declines, primarily driven by the loss, fragmentation, and conversion of grasslands into intensive agricultural lands or urban developments. Ground-nesting habits leave them highly susceptible to terrestrial predators, agricultural machinery, and modern threats such as collisions with wind turbines, power lines, and secondary poisoning from rodenticides.



Compilation and publication: EcoRegistros – 11/07/2026





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Geographic distribution


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Species photographs

Last published photographs

Foto
Photography ID: 633799
 
Casilda
Santa Fe
Argentina
05/07/2025
Adrian Braidotti
Foto
Photography ID: 633574
 
Casilda
Santa Fe
Argentina
05/07/2025
Adrian Braidotti
Foto
Photography ID: 633573
 
Casilda
Santa Fe
Argentina
05/07/2025
Adrian Braidotti
Foto
Photography ID: 633572
 
Casilda
Santa Fe
Argentina
05/07/2025
Adrian Braidotti
Foto
Photography ID: 594668
 
Casilda
Santa Fe
Argentina
07/20/2023
Adrian Braidotti
Foto
Photography ID: 542222
  Adult

Casilda
Santa Fe
Argentina
07/09/2023
Lucas Lalegge
Foto
Photography ID: 541952
 
Casilda
Santa Fe
Argentina
07/20/2023
Adrian Braidotti
Foto
Photography ID: 541897
  Adult

Casilda
Santa Fe
Argentina
07/08/2023
Milton Gerardo Vesco
Foto
Photography ID: 539519
 
Casilda
Santa Fe
Argentina
06/24/2023
Adrian Braidotti
Foto
Photography ID: 539339
  Adult

Casilda
Santa Fe
Argentina
06/25/2023
Tramannoni Ariel



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 Detail of places sorted by number of records








Page 1
Record IDDateExact timeCountryProvince / departmentPlaceFilmedPhotographedRecorded vocalObservedHeardWounded or deadNumber of individualsUser or BibliographyDetail
228501007/05/2025ArgentinaSanta FeEscuela Rural, CasildaAdrian Braidotti
179479820/07/2023ArgentinaSanta FeEscuela Rural, CasildaAdrian Braidotti
179683709/07/2023ArgentinaSanta FeCasildaLucas Lalegge
179465508/07/2023ArgentinaSanta FeCasildaMilton Gerardo Vesco
178399225/06/2023ArgentinaSanta FeArroyo Zona Rural, CasildaTramannoni Ariel
178346024/06/2023ArgentinaSanta FeEscuela Rural, CasildaAdrian Braidotti
Page 1

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Recommended citation
Please use the following reference when citing this species account.
EcoRegistros. 2026. Short-eared Owl (Asio flammeus) – Species account. Accessed from www.ecoregistros.org on 24/09/2026.