suggested reading for your cat:
Woods M., R. A. McDonald, S. Harris (2003)
Predation of wildlife by domestic cats
Felius catus in Great Britain -
Mammal Rev. 33: 174-188
May, R. M. (1988): Control of feline delinquency
- Nature 332: 392-393
Special note: The robin, which spends much of its time on or near the ground, is especially endangered by domestic cats.