We have never tried to define how long you can wait as we just clean at the end of the hunt. Just a guess but I'd say eight hours would be our max.
I know that in some countries, they hang a bird, by the neck, for days or until the head separates from the body. I don't think they do this without first cleaning. You may have noticed that wild game meat, will keep longer than domestic meat.
I usually clean them as soon as possible because as the food in the crop starts to leach out they start to taste a little funny after a few hours, definitely gamey after 10 hours.
