Short-eared Owl

Asio flammeus

Family: Strigidae (Typical Owls) Global: LC National: VU

Short-eared Owl

  • Scientific Name: Asio flammeus
  • Nepali Name(s): लघुकर्ण लाटोकोसेरो (Laghukarna Latokosero)
  • IUCN Red List Status: Least Concern (LC)
  • National Red List Status: Vulnerable (VU)
  • CITES Appendix: Appendix II
  • CMS Appendix: Not listed

Measurements & Physical Profile

  • Body Length: 34–42 cm
  • Wingspan: 85–110 cm
  • Weight: 200–475 g

Did You Know?

Unlike most owls, the Short-eared Owl is distinctly diurnal (active during the day) and crepuscular (active at dawn and dusk). It is highly nomadic, traveling vast distances to find areas with high rodent populations, and is one of the most widely distributed owls in the world. It gets its name from its very small ear tufts, which are usually invisible unless the bird is agitated or alert.

Distribution and Habitat

Global Distribution

The Short-eared Owl (Asio flammeus) is one of the world's most widespread owl species, occurring on every continent except Antarctica and Australia. Its breeding range extends across North America, Europe, and Asia, with additional populations in South America, Hawaii, and many oceanic islands. Northern populations are strongly migratory, wintering farther south in temperate and subtropical regions, including the Indian subcontinent.

Distribution within Nepal

In Nepal, the Short-eared Owl is a rare winter visitor and passage migrant, occurring mainly in the Terai and inner valleys. It is most frequently recorded around the Koshi region, with scattered records from Chitwan, Rupandehi, Dang, Rautahat, Sarlahi, Sunsari, Annapurna and Taplejung. The species occupies open grasslands, river floodplains, marshes, and agricultural landscapes during winter, with recent records indicating that it may be overlooked rather than genuinely scarce.

Preferred Habitats

The Short-eared Owl inhabits extensive open landscapes, including natural grasslands, marshes, floodplains, coastal dunes, heathlands, wet meadows, and agricultural fields. During winter in Nepal, it commonly uses tall grasslands, riverine floodplains, and harvested croplands where rodent populations are abundant. Unlike most owls, it avoids dense forests and depends on low vegetation that allows efficient low-altitude hunting and ground roosting.

Elevational Range

In Nepal, the species occurs primarily in the Terai and inner river valleys below 1,000 m. Elsewhere in its global range it occupies habitats from sea level to alpine tundra, but wintering birds in Nepal are largely confined to lowland grasslands and wetlands.

Seasonal Occurrence

The Short-eared Owl is a winter visitor to Nepal, arriving between October and November and departing during March and April. Most records occur from November to February, coinciding with peak wintering periods. The species is also a passage migrant during spring and autumn migration and may shift locally in response to fluctuations in rodent abundance.

Behavior and Ecology

Flight and Foraging Behavior

The Short-eared Owl is renowned for its slow, buoyant, moth-like flight, hunting low over grasslands with deep wingbeats interspersed with glides. It locates prey primarily by its exceptional hearing and vision, often hovering briefly before dropping onto rodents concealed in dense vegetation. Unlike many owls, it is frequently active during the day, particularly at dawn and dusk.

Social and Roosting Habits

Although usually solitary while hunting, the species often forms loose communal winter roosts, especially where prey is abundant. Birds roost on the ground among tall grasses, reeds, or low shrubs, relying on camouflage for protection. Individuals may remain remarkably motionless when approached before flushing at close range.

Diet and Ecosystem Role

Diet Breakdown

The Short-eared Owl is a specialized predator of small mammals, particularly:

  • Rodents (primary): voles, mice, rats, shrews, and lemmings.
  • Birds: small ground-dwelling birds and passerines, especially during winter.
  • Other prey: occasionally rabbits, bats, and large insects when rodents are scarce.

Ecological Role

As a major predator of rodents, the Short-eared Owl provides valuable natural pest control in grasslands and agricultural landscapes. Its dependence on extensive open habitats and healthy rodent populations makes it an important indicator of well-managed grassland and wetland ecosystems.

Breeding Biology

The Short-eared Owl does not breed in Nepal. Throughout its breeding range in the Northern Hemisphere, it nests directly on the ground in shallow scrapes concealed beneath grasses or low shrubs. Females typically lay 4–7 eggs (occasionally more during rodent population booms), incubating them for about 24–30 days while males provide food. Young leave the nest before they can fly and become fully independent several weeks later.

Migration

  • Status: Winter visitor and passage migrant in Nepal.
  • Movement: A highly migratory and nomadic species whose movements are strongly influenced by seasonal fluctuations in rodent abundance. Northern breeding populations migrate south to wintering areas across Europe, Africa, southern Asia, and the Indian subcontinent, including Nepal.

Population Status

  • Global Population: Approximately 1.2–2.1 million mature individuals.
  • PopulationTrend: Overall decreasing, although populations fluctuate naturally with prey abundance.
  • National Population Estimate (Nepal): Unknown.
  • Monitoring: There are currently no systematic population monitoring activities for this species in Nepal.

Threats

  • Habitat Loss: Conversion of natural grasslands, marshes, and wetlands into intensive agriculture, plantations, and urban areas has reduced wintering and roosting habitat.
  • Rodenticides and Pesticides: Secondary poisoning from rodenticides and agricultural chemicals threatens both adults and their prey base.
  • Human Disturbance: Disturbance of communal winter roosts through grazing, burning, agriculture, and recreational activities can force birds to abandon suitable habitat.
  • Climate Change: Altered grassland ecosystems and changing prey cycles may affect winter distribution and breeding success across its range.

Conservation Actions

Existing Measures

  • Legal Protection: Listed under CITES Appendix II, regulating international trade.
  • Protected Areas: Wintering birds occur in protected grasslands and wetlands, including Koshi Tappu, Chitwan National Park, and other Terai protected areas.
  • National Status: Listed as Vulnerable in Nepal's National Red List, highlighting the need for targeted conservation.

Recommended Measures

  • Grassland Conservation: Protect and restore native grasslands, marshes, and floodplain habitats within and outside protected areas.
  • Reduce Rodenticide Use: Promote integrated pest management to minimize secondary poisoning.
  • Protect Winter Roosts: Prevent burning, excessive grazing, and disturbance of known roosting sites during winter.
  • Monitoring and Awareness: Strengthen winter surveys and educate local communities on the ecological importance of grassland owls as natural rodent controllers.

References

  1. BirdLife International. (2021). Asio flammeus. The IUCN Red List of Threatened Species 2021.
  2. Grimmett, R., Inskipp, C., & Inskipp, T. (2016). Birds of Nepal. Christopher Helm, London.
  3. Inskipp, C., et al. (2016). The Status of Nepal’s Birds: The National Red List Series. Royal Zoological Society of London.
  4. König, C., & Weick, F. (2008). Owls of the World. Christopher Helm, London.