Cat's in general left outdoors, do not do as well as indoor cats. Fleas, ticks, diseases, attacks by predictors, and moving vehicles take their toll. I suppose people see cats stalking birds and think cats do just fine outdoors.
Many years ago, I worked as an assistant manger in a large apartment complex. People would move out leaving their cats believing some kindly neighbor would take care of them. Occasionally that happened but not often. When a cat is abandoned and left around the house or apartment, it will usually hang around a day or so, waiting to be let in and fed. As it becomes more hunger it will begin to roam. Unlike dogs, who are pack animals, cats are solitary. They hide under bushes and cars waiting for dark to search for food. They do not seek out humans the way dogs do. The lucky find a human but most die within a year or so.
Parks, truck stops, and rest areas seem to be a favorite place for people to dump their pets. Unfortunately they are the worst place. Many of the animals are run over by cars. Maintenance people will usually run them off. Most wander into wooded areas searching for food where they become easy pray for predators. Cats that survive for very long usually become feral and will never find a home.
If you have to abandon your pets, take them to a shelter. Many people think their pets stand a better chance if they are left in the neighborhood because they will be put down if left in a shelter. Today, no kill shelters are popping up all over the country. Those that aren't no kill shelters have a pretty good record of placing the animals. Many shelters will attempt to place animals in other shelters if they can not place them.
Before deciding to adopt that cute kitten are puppy, you need to consider that cute little bundle of fur is going to grow into an adult dog or cat that will be dependent on you for 10 or 20 years. If your not ready to make the commitment to care for the animal throughout its life, you shouldn't adopt it.