The species occupies coniferous forests, breeding mainly in spruce (Picea) forests but also uses mixed forests of pine (Pinus), birch (Betula) and aspen (Populus tremula) and even uses pure pine forests (Hagemeijer and Blair 1997). Breeding may begin in February, in good vole years (Mikkola 1983) and continue until July (Holt et al. 1999) but most eggs are laid in April. It nests in holes, such as disused woodpecker holes or where these are not available it will use nest boxes. No nest is made and eggs are laid directly onto debris, although if there is soft material in the hole it will make a shallow depression (Mikkola 1983). Clutches are usually three to seven eggs. It feeds principally on small voles as well as mice, shrews and small birds (Snow and Perrins 1998), but also recorded taking flying squirrels, bats, frogs and beetles (Mikkola 1983). This species is generally a year-round resident within a stable home range, but it disperses in years when prey is scarce (Holt et al. 1999).

Conservation Actions Underway
CITES Appendix II. EU Birds Directive Annex I. Bern Convention Appendix II. Nest boxes have been employed extensively in Europe to help mitigate loss of nest-sites and to monitor demographic characteristics, for example by ringing nestlings; Around 11,000 boxes have been installed in Finland from which fledglings ringed annually (Holt et al. 1999).

Conservation Actions Proposed
Careful forestry management is required for this species. Selective harvesting may allow tree removal while maintaining suitable habitat for the species. In addition, because forest succession is slow in spruce-fir forest, practices must acknowledge that clear-felled sites will remain unsuitable for roosting or foraging for up to a century, and new nest trees will not develop for up to two centuries (Holt et al. 1999). The provision of nest boxes has proved effective and this practice should continue. Predation by martens can be reduced by placing a strip of metal or plastic c. 50 cm wide above and below nest holes and the use of ‘anti-marten’ boxes can be effective (König et al. 2008).