Lonesome George was a Pinta Island tortoise, known to be the last surviving member of his species. He lived in the Galápagos Islands until his death in 2012 at the age of 100 years old. Lonesome George became an icon of conservation efforts as his story highlighted the devastating impact of human activity on endangered species. Despite attempts to mate him with females of similar tortoise species, Lonesome George did not produce any offspring, and his death marked the extinction of his subspecies.

There are several animals that have been dubbed "the loneliest animal in the world" due to their unique situations. Here are the details:

The Loneliest Whale in the World - This refers to a specific whale with a unique vocalization of 52 hertz, which is much higher than the typical range for blue whales. The whale's calls have been heard for decades, but it has never been seen or identified. Its unique vocalization makes it difficult for other whales to communicate with it, leading to its lonely reputation.

Kiska the Orca - Kiska was a captive orca whale that spent 44 years in isolation at a Canadian amusement park. Due to her prolonged isolation, the Whale Sanctuary Project referred to her as "the loneliest whale in the world." Kiska died in March 2023 due to a bacterial infection.

Bua Noi the Gorilla - Bua Noi is a gorilla housed at the Pata Zoo in Bangkok, Thailand. Animal activists have referred to her as "the world's loneliest gorilla" due to her solitary confinement in a small enclosure at the top of a department store.

Overall, the label "the loneliest animal in the world" is often used to bring attention to the plight of animals in isolation, whether they are in captivity or unable to connect with others of their kind due to unique circumstances.