“Lifespan” of non-excavated holes in a primeval temperate forest: A 30Â year study

► Non-excavated holes used by birds often in short supply in managed woods. ► They persisted for up to 30 years in strictly protected Białowieża National Park. ► Holes persisted for a median 11-13 years in deciduous forests. ► Their lifespan varied by tree species; holes in large live trees persisted longest. ► The existing hole trees should be retained in the forestry operations.