Normally docile songbirds have taken to attacking, killing and eating cave-dwelling bats, scientists have found.
The Telegraph 9 Sep 09;
Researchers at the Max Planck Institute for Ornithology in Germany observed great tits hunting and killing hibernating pipistrelle bats for food in a Hungarian cave.
Scientists watched the birds over the course of three winters and found that the tits foraged for bats far less when given extra food, indicating they only started hunting when they suffered from a shortage.
The tits may have eavesdropped on calls of awakening bats to find them in rock crevices, they said.
The report, by Peter Estok, Sandor Zsebok and Bjorn M Siemers and published in the Royal Society Journal Biology Letters, said: ''Upon disturbance and when waking up, torpid hibernating bats utter audible calls, which might help the tits localise bats in crevices.
''We recorded these calls and played them back at the cave entrance to test whether they are audible to the tits and elicit any specific behavioural reaction.''
The tits could clearly hear the calls and were attracted to the loudspeaker, the scientists found.
''Ecological pressure paired with opportunism can lead to surprising innovations in animal behaviour,'' the report said.
