Batting for Tits?

It has been reported (http://www.guardian.co.uk/science/2009/sep/09/great-tits-hunting-bats) that scientists from the Max Planck Institute have found that a group of Great tits (Parus major) have taken to hunting and consuming hibernating pipistrelle bats in a remote Hungarian cave. Admittedly, the presumably hungry birds could be distracted by offers of sunflower seeds and bacon scraps (things they normally eat in the UK) but they were recorded to kill 16 bats over 22 days of observation. The birds also flew to investigate speakers broadcasting bat calls that were placed in the cave mouth. It would be interesting to know whether this behaviour is limited to this particular population of Great tits or is a more widespread phenomenon.