In the animal kingdom, there are a few individuals who hold the title of being the loneliest creatures on Earth. Let's take a quick look at some of them.
The Vaquita, a small porpoise in the Gulf of California. Lonesome George, the last of his kind, a Pinta Island tortoise. Sudan, the northern white rhino, standing as one of the last of his subspecies. And the Lonely Frog, also known as Romeo, searching for a mate.
