Some cat owners may have noticed their kitty has particular tastes when it comes to the half-eaten presents left on the doorstep.

Be it mouse, rat, bird or lizard, a survey of house cats living in Sydney's eastern suburbs has found a good proportion focus their hunts on specific targets.

Fussy: Research has shown that cats often obsess over their choice of food.

Professor Chris Dickman, the research leader, said some felines were such determined killers they would hunt their prey of choice until they had vanished from the area.

This obsessive behaviour, also documented in feral cats, was having a noticeable effect on prey populations, said Professor Dickman, from the University of Sydney.