Lectures: 24

Runtime: 21 Hours, 8 Minutes

A cockatoo who held court in an Australian pub for the better part of a century. A distillery cat credited with 28,899 mice. A tortoise said to have been given by Captain Cook to the royal family of Tonga. An eel dropped down a Swedish well in 1859 that stayed a century and a half. An alligator who came through two bombing campaigns over Belgrade. An albatross still laying eggs past seventy, found again by the man who first banded her in 1956.

Nature’s Immortals, course #20 from Unteachable Courses, tells 24 of the longest animal lives ever recorded: who these animals were, the people who fed, worshipped and exhibited them, and the paper trails that turned an old animal into a famous number. Temple ledgers, canal-company accounts, newspaper clippings, zoo studbooks, a shipping manifest, a scale reading under a single lens, a numbered metal band. Where the documents run out, the legends take over, and we follow both.

Woven through every story is the comparative biology of long life. Why some tortoises barely seem to age. Why big dogs die young. How a fish’s scales, a whale’s photo-ID catalog and a parrot’s studbook produce different kinds of certainty. What captivity, isolation and war do to a body. And why the most celebrated age records on Earth range from a birth time logged to the minute to the standing of a royal office.

Six acts move from roadside attractions, to royal and sacred animals, to family heirlooms, to survivors of war and neglect, to lifelong bonds between one keeper and one animal, and finally to the record books.

Part natural history, part biography, part deadpan comedy: rigorous without becoming a nature documentary, funny without being flippant, and honest about the gap between an age that was measured and one that was loved into existence. For anyone who has ever wondered not just how long an animal can live, but how we could possibly know.

Syllabus:

1. Cocky Bennett: The Oldest Parrot Ever?

2. Towser: The Cat Who Slayed 28,899 Mice

3. Poncho: Famed Macaw & Hollywood Actress (97 Years)

4. Fungie: Oldest Solitary Dolphin (40 Years)

5. Tu’i Malila: Captain Cook’s Tortoise Gift To Tonga’s Royals

6. Alagba: Nigeria’s Legendary 344 Year-Old Royal Tortoise

7. Chengalloor Dakshayani: Hindu Temple Elephant, Oldest Ever in Captivity

8. Hanako: 226-Year-Old Koi?

9. Adwaita: Kolkata’s 255-Year-Old Tortoise

10. Ale The Brantevik Eel: 155 Years Old?

11. Methuselah: The Oldest Living Fish in Captivity

12. Muja: Serbia’s Century-Old Alligator

13. Gregoire, World’s Oldest Chimpanzee (66 Years)

14. Shirley: Fidel Castro, The Circus & a 72-Year Elephant Life

15. Greater: World’s Oldest Flamingo

16. Henry: World’s Oldest Lizard Finally Became a Father at 111

17. Cookie: Oldest Cockatoo In Captivity (83 Years)

18. Creme Puff: The Oldest Cat Ever (38 Years)

19. Bluey: Oldest Verified Dog Ever (29 Years)

20. Old Billy: The Oldest Horse Ever (62 Years)

21. Colo: Oldest Gorilla In The World (60 Years)

22. Granny (J2): Oldest Orca Ever?

23. Jonathan: 193-Year-Old Tortoise, The Oldest Land Animal on Earth as of 2026

24. Wisdom: The Oldest Wild Bird on Earth As of 2026

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