Skip to content

Western Finland’s Short-eared Owl Breeding Population Fell More Than 50% as Grassy Habitat Shrunk 46%

Short-eared Owl in flight at Spiekeroog, Germany
Conservation · Threats

A 47-year study in western Finland found that the local breeding population of Short-eared Owls (Asio flammeus) declined by more than half as grassy farmland habitats important to their vole prey shrank by 46%.

Detailed breeding monitoring from 1977 to 2006 showed how strongly the owls tracked food. More Short-eared Owls bred in years with abundant spring voles, and those years also produced larger clutches and more nestlings. Nest failures were attributed mainly to agricultural activity and predation.

The researchers extended population monitoring across a broader area of about 1,000 km² through 2023. Across the full 47-year period, the local breeding population declined by more than 50%, with the modelled long-term trend corresponding to an average annual decrease of 2.8%.

Over the same period, pastures and hay fields were increasingly replaced by cereal, potato and oilseed crops, while open drainage systems became less common. Together these changes reduced grassy habitats suitable for voles and foraging owls by 46%. The authors conclude that structural simplification of farmland associated with agricultural intensification is a primary driver of the long-term decline in this grassland and farmland population.

Sources and image credit

  1. Korpimäki, E., Klemola, T., & Koivula, M. (2026). Population dynamics and reproductive success of Short-eared Owls in relation to widely fluctuating food abundance and farmland habitat degradation.Primary research article first published online 3 September 2026. The accessible primary abstract reports that breeding density and reproductive output increased with spring vole abundance; monitoring extended through 2023 showed a local breeding-population decline of more than 50% over 47 years, averaging 2.8% per year, while grassy farmland habitat suitable for voles declined by 46%. The publisher PDF is listed in the primary Finnish repository but could not be independently retrieved during this review, so no additional PDF-only details were added.

Image: Short-eared owl in flight at Spiekeroog, Lower Saxon Wadden Sea National Park, Germany, 22 May 2018. Photo: Stephan Sprinz / Wikimedia Commons. CC BY 4.0. Representative species image; not a study bird. · CC BY 4.0 · Source

About this content: This story was produced with AI assistance within an editorial workflow developed by Wildlife Vagabond. Editorial responsibility remains with Wildlife Vagabond.How AI is used

Threats

SPECIES IN THIS STORY

Species in this story

Short-eared Owl Asio flammeus Explore species

Independent research and conservation news archive

Did you find this information useful?

Wildlife Vagabond is independently built and maintained. Voluntary support helps cover source verification, hosting and continued work on research and conservation news.

Support Wildlife Vagabond

The news archive will remain freely available.