Risk of nest predation in three species of hole nesting owls: influence on choice of nesting habitat and incubation behaviour

  • Published source details Sonerud G.A. (1985) Risk of nest predation in three species of hole nesting owls: influence on choice of nesting habitat and incubation behaviour. Ornis Scandinavica, 16, 261-269.


This study is summarised as evidence for the following.

Action Category

Provide artificial nesting sites for owls

Action Link
Bird Conservation
  1. Provide artificial nesting sites for owls

    A replicated, controlled study in 1970-83 in boreal forests in Hedmark, Norway (Sonerud 1985), found that three species of owl appeared to nest preferentially in nest boxes, compared to natural cavities. Pygmy owls Glaucidium passerinum showed the weakest preference (55% of 20 nests were in nest boxes), followed by hawk owls Surnia ulula (75% of 12 nests in boxes) and Tengmalm’s owls Aegolius funereus (97% of 167 nests in boxes). The number of nesting cavities available is not recorded. Tengmalm's owls used boxes on isolated trees in clear-cuts most, and those closed mature forest the least. Pygmy owl boxes were smaller (with a 45 mm entrance hole) than other boxes (with a 58 mm entrance) and only one (5%) was predated, compared to 69 (37%) Tengmalm’s owl clutches and four (33%) hawk owl clutches.


Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust