Discover the Mysterious Snake-Infested Island with Only Two Human Residents

Written by Chanel Coetzee
Updated: May 28, 2023
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This tiny island looks like it comes straight out of an adventure/fantasy novel. But it is actually home to a huge population of mutant tiger snakes. Mount Chappell Island, Tasmania, is home to Australia’s largest and most venomous tiger snakes. These snakes are said to be twice the size of their cousins on the mainland. As a result, the island is notorious, and there are several horror stories of tourists scrambling to get off Mount Chappell when seeing dozens of slithering snakes within minutes of their arrival. This mysterious snake-infested island has only two human residents. Let’s learn about their incredible experience with an infestation of tiger snakes.

Ranger Grahame Stonehouse Is A Resident of this Mysterious, Snake Infested Island

Pakana ranger Grahame Stonehouse is one of the residents of Mount Chappell Island. In fact, he has split his time between this island and the mainland for 11 years. That is a lot of time alone with what he explains are tiger snakes twice as big as their cousins in other areas of Australia. However, he believes the myths about these mutant snakes are out of hand, but they are bigger, and there is a lot of them. It’s easy to identify these snakes because they are black and don’t have any stripes. Mr. Stonehouse loves being one of the island’s two residents because he enjoys the calm scenery, which has helped him re-establish a connection to his country and culture after moving away from Tasmanian for many years as a child.

Herpetologist Simon Fearn, the Other Resident of this Snake Infested Island

Simon Fearn is a scientist who has studied reptiles for years. In addition, he is a member of the Natural Sciences team at the Queen Victoria Museum and Art Gallery. This herpetologist was even bitten by one of these mutant snakes during one of his visits to this snake-infested island in 1991. He derived that a large tiger snake population was stranded on the island when the sea level rose after the last Ice Age.

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Furthermore, it’s extraordinary that these snakes have survived all these years because animals stuck on tiny islands like this one usually don’t survive, making prey for these snakes an issue. However, there is a large population of breeding Mutton birds on the island, and these snakes love to eat their chicks. But the snakes can only consume these chicks up to five weeks of age, after which they become too large to devour. Therefore, the smaller the snake’s head, the less time they have to feed on these rapidly growing chicks. Stats show that Mount Chappell Island houses around 20,000 baby tiger snakes each year, but only one percent make it to adulthood.

The Snakes on Mount Chappell Island

Tiger snakes on Mount Chappell Island have evolved over thousands of years to adapt to their surroundings. For example, their heads are larger than other tiger snakes found in Australia because their primary food source (Muttonbird chicks) grows quickly, and they need bigger heads to consume them. February is the best month for hunting these birds, so this is when these snakes are at their heaviest. After that, they slowly lose weight and reduce their activity to preserve energy for the next hatching season.

Fern states that all they do for the rest of the year is burn off fat, which is quite unique because there is no other food source for these snakes. Additionally, the tiger snakes on this island are likely the most deadliest of their kind in Australia. While their venom is less toxic than tiger snakes on the mainland, they have large fangs, which can deliver a larger dose. So, this mysterious snake-infested island may be unique, but there are approximately 40 islands around the Bass Strait, and many are still untouched, so Mr. Stonehouse believes there are other thriving mutant snake populations out there.

Tiger snake - Notechis scutatus highly venomous snake species found in Australia, Tasmania.

Tiger snake –

Notechis scutatus

highly venomous snake species found in Australia.

©Martin Pelanek/

Mount Chappell Island

This island derived its name from Matthew Flinders, as Chappell was his wife’s maiden name. Currently, it is a privately owned island primarily used for grazing sheep and Cape Barren geese. In addition, Mount Chappell Island forms part of the Chalky, Big Green, and Badger Island Groups Important Bird Area. Unfortunately, Mount Chappell Island’s habitats have been damaged by plowing,  grazing, burning, and slashing.

The island also served as a breeding ground for little penguins, but they have since moved on. Besides sheep, other animals were intentionally introduced to the island; they include:

  • Rats
  • Reptiles
  • Feral cats
  • Spotted skink
  • Bougainville’s skink
  • Metallic skink
  • Three lined skink
  • Tiger snake

Where is Mount Chappell Island Located on a Map?

Mount Chappell Island is a granite island with a landmark cental hill. It is part of the Furneaux Group, within the Bass Strait, lying west of the Flinders and Cape Barren islands, Tasmania, south of Victoria, in south-eastern Australia.

The photo featured at the top of this post is © Benoit MOREL/

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About the Author

Chanel Coetzee is a writer at A-Z Animals, primarily focusing on big cats, dogs, and travel. Chanel has been writing and researching about animals for over 10 years. She has also worked closely with big cats like lions, cheetahs, leopards, and tigers at a rescue and rehabilitation center in South Africa since 2009. As a resident of Cape Town, South Africa, Chanel enjoys beach walks with her Stafford bull terrier and traveling off the beaten path.

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