hey this happened with our Reavy..
(our 5year old Bengal, very lovely cat - very gentle never once scratched me and very tolerant with our 2 and 4year old girls)
We went camping a couple of times last summer - even though we left plenty of food and mom came by to check on him - each time we went away he was gone for a few days. He was an outside cat and we have a cat door. Then we went away for the labour day weekend and he didnt come back.
Actually he would come by occasionally and looking healthy and well fed, but he seems to have abandoned us for a house a few doors down. I guess he got a better deal there. I still put out his food for him but after a few months I got tired of feeding all the neighbourhood cats and locked the cat door. He still comes by once in a while but just to say hi.