A nest check in a barn in Haarlemmermeer unexpectedly became a rescue operation when owl expert Bert-Jan Bol and assistant Roel Draijer examined a nest of church owls. They removed, weighed, measured and ringed seven owls. The area is having an exceptionally good year, which has been linked to an abundance of mice: nests with seven young are no longer unusual, and volunteers found nine eggs or young in three nests.

The count in Haarlemmermeer has reached 26 owls, matching the 2019 record while the breeding season is still under way. Volunteers have already recorded 16 late or second broods, compared with 11 in 2019. Bol and Draijer began installing nesting boxes in 1989; after years of mostly empty boxes, breeding became annual from around 1995. Habitat loss from construction and disappearing farms may limit further growth, and Bol expects that many young owls will not survive their first year.