Where do unfixed tomcats go when they're about 1 year old, never to be seen again?

They go looking for mates whom they can smell up to a mile away. On the way, they can run into trouble like dogs, coyotes, cat hoarders who take them in, animal control, people with guns(who don't like to hear mating calls in the middle of the night), yummy puddles of antifreeze, cars, other males to fight with over mates, I could go on forever. It's dangerous to let cats outside but an almost certain way to never see your male cat again is to leave him out not neutered. If you do find him, take him immediately to be fixed and keep him indoors where he's safe.