If you’re an animal lover, it can be heartbreaking to hear that a species has gone extinct-especially because humans are typically to blame. But we have been wrong before, like the case of the ivory billed woodpecker, which was declared extinct not once but twice. Another bird that might still be around is the passenger pigeon; even Theodore Roosevelt claims that he saw a flock of them after they were thought to be long gone. The baiji, also known as the Chinese river dolphin, is a creature that was driven to extinction in modern times, but there may still be some of them out there. You’ve heard of Tasmanian devils, but the Tasmanian tiger was a very unique and distinctive creature that there are still sightings of to this day. The eastern cougar is thought to be long gone, but many people believe that it has simply relocated.