A domestic cat could manage at least 2 weeks without food & water. I had one accidentally cemented into an outside drain for 2weeks before I discovered where the mews were coming from. She drank the whole day when released ;-))
There are a lot of young birds about (flocks of starlings here) and the cats are on the prowl for tasty foodies.....they're fed up with the regular cat food (left that to you) and taken off for a feast.