Just to reinforce my argument ref readily available food for willdlife - the foxes round here seem to leave the rabbits alone, if the increase in numbers these past few years is anything to go by. Easier targets are the chickens & other poultry which are now housed on the land adjoining mine. I often find part-carcases in the hedgerows & lanes, so it's clearly far less effort for the fox to get into the poultry runs, or catch the birds which escape, than it is for them to catch rabbits.
p.s. forgot to put in previous thread that I don't think you need a licence for an air rifle, which is what I think was used in the case in question.