Continuous low-intensity predation by owls () on bats () in Spain and the potential effect on bat colony stability.

Owls prey on bats, but information on owl predation is scarce, its impact on bat mortality is unclear, and reports on behavioural responses, including roost-switching and fission-fusion behaviour, are equivocal. To study the link between owl predation and anti-predator behaviour in bats, we evaluated seven months of video recordings at roosts and the behaviour of 51 passive integrated transponder (PIT)-tagged bats and bats without tags in a geographically isolated colony of greater noctule bats () in Spain. We found the tawny owl to almost continuously hunt , from perches and on the wing, well after the bats emerged at dusk and when they returned to their roosts.