Some animals naturally live alone, but others are forced into isolation by habitat loss, climate change, or shrinking populations. Here are five of the world’s loneliest animals — they do not choose to be alone; it is simply all that is left. Lonesome George (Pinta Island tortoise)Lonesome George was the last known Pinta Island tortoise and is perhaps the most famous symbol of loneliness. It was discovered in 1971 on Ecuador’s Galápagos Islands and lived alone for decades, despite conservationists’ efforts to find it a mate. When it died in 2012, its subspecies became extinct, making it a global reminder of a loss that cannot be undone.