The Survivors Post-Human Existence

Cats - Indoor cats will need to get outside to survive, as after munching on leftover food and drinking melt water from freezers, they will soon run out of provisions. Once outside, cats have a great chance at survival. Because they have generally retained their independent natures and are natural hunters, they will quite easily return to the wild and provide for themselves by hunting birds and rodents. They will, however, have to watch out once predators, such as bobcats, coyotes and wolves, move back into abandoned human neighborhoods.

Small Dogs - Bred over hundreds of years to be smaller, easier to care for and to require less food and exercise, small breeds of dogs, like the ever-popular chihuahuas, Yorkshire terriers and pugs, will have difficulty staying alive after the demise of their owners. Although they can be highly intelligent, these small dogs have short legs and little strength or endurance, which will make it difficult for them to compete for food-if they can even make it out of the house, the first test of their survival. The smallest dogs probably won’t last a week without humans.

Medium-sized Dogs - If they can get out of the house, medium-sized dogs stand the best chance of survival of all the canines. Because of their long, lean legs, medium-sized dogs need the least amount of energy to run fast and far-an advantage when it comes to competing for food. But, over many years of breeding by humans, their hunting instincts have largely disappeared, so they'll face a challenge after they can no longer scavenge what humans leave behind. That's when they'll be forced to turn to the easiest prey they can find—very possibly, small dogs. Eventually, the successful dogs will form packs to hunt larger prey.

Zoo Animals - If zoo animals are able to make it out of their enclosures, their wild instincts give them a good shot at survival even after their zookeepers are long gone. As nature works to reclaim the Earth, lions and tigers might be found stalking their prey through former cities and suburbs while rhinos and elephants graze on newly revitalized plains.

Mice and Rats - The first weeks and months after the disappearance of people will be a bonanza for rats and mice, as they eat their way through abandoned kitchens, grocery stores and any place where food is found. But after that, these rodents will find it pretty tough going. Without human garbage to snack on and water piped in by people to drink, they'll resort to eating cardboard, cloth, glue and finally, each other. Eventually, they'll be forced outside, where they'll be picked off by hungry predators. Although they will most likely survive, their populations will plummet.

Coyotes and Bobcats - Smaller predators like coyotes and bobcats would be some of the first wild animals to colonize our abandoned neighborhoods. They would likely prove a threat to weaker domesticated species like small dogs and cats. As nature slowly takes back cities and suburbs, and deer and other larger prey spread out, larger predators like wolves will also arrive.

Cockroaches - There's no doubt about it, cockroaches are survivors, and they'll be around long after people. But, they too will face challenges. Although they can eat almost anything—from starch to grease to cardboard—they also need warmth and may struggle to survive the winter in cooler northern cities.