Provision of nest boxes for pygmy owls Glaucidium passerinum, Tengmalm's owls Aegolius funereus and hawk owls Surnia ulula at three sites in Hedmark, Norway
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
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.
Provide artificial nesting sites for owlsAction Link
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.