The word is 'feral' . Feral usually refers to a creature ( or its offspring or descendants) that was once domesticated but lives wild. There are many feral cats in the UK- they can manage quite well without humans. Most town pigeons are feral pigeons- you dont get many feral dogs in the UK- they cant manage on their own!
Feral cats can be tamed too - I have Sooty and Soo asleep in my kitchen at the moment - they are very loving cats - a year ago we could not get near them - they are still very upset by strangers thoygh