Winter predation by Common Kestrel Falco tinnunculus on Pipistrelle Bats Pipistrellus pipistrellus in Southern Spain

Between January and March 1990 we radio-tracked a male Common Kestrel Falco tinnunculus which hunted Pipistrelle Bats Pipistrellus pipistrellus at dusk on 11 of 15 days of observation. Bats left their roosts earlier, and in greater numbers, during fine weather (i.e. high air pressure, no rainfall and low wind speed). The Kestrel showed no interest in bats during poor weather and went to roost early, even though some bats were flying. From pellet analysis, we estimated that bats represented between 30% and 60% of the items eaten by this Kestrel