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Congratulations on your new fluffy record, Tufted Ground Squirrel. Please don’t eat our livers.

It's a record that none of us even knew existed, but the tufted ground squirrel from Borneo is the official owner of the Fluffiest Tail in the World. Good job, tufted ground squirrel.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


It’s a record that none of us even knew existed, but the tufted ground squirrel from Borneo is the official owner of the Fluffiest Tail in the World. Good job, tufted ground squirrel. We’ll never know the sacrifices you made to achieve such fluff, the lost time with your family and friends that you’ll never get back due to whatever maintenance fluff requires, but we respect an animal with ambition.

We also respect an animal with a taste for blood, no matter how fluffy. Please don’t hurt us.

The tufted ground squirrel (Rheithrosciurus macrotis), which grows to around double the size of a regular squirrel, has a reputation for hunting deer - well, more like serial killing deer - if local legends are to be believed. According to Erik Stokstad at Science Magazine, "Hunters say that the squirrels will perch on low branches, jump onto a deer, gash its jugular vein, and disembowel the carcass.” The squirrels would then eat the deer’s stomach contents, liver and heart. Another version of the legend from villages close to the forest edge tells of these squirrels killing domestic chickens and eating their hearts and livers only.


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"It sounds pretty fantastical," Roland Kays, a zoologist at the North Carolina Museum of Natural Sciences, told Stokstad. "Even more than its fluffy tail.” You’re next, Kays.

These Homicidal Masters of Fluff are also super hard to find. Conservation scientist Erik Meijaard from the People and Nature Consulting International in Jakarta and his wife, Rona Dennis, set up a camera trap in the hilly forest of Borneo to catch a glimpse of the mysterious species.

Dennis, a remote sensing scientist, and their daughter Emily Mae Meijaard, analysed the pictures to figure out how big the animal and its tail is. Hinting at just how rare these odd creatures are, the team was only able to get seven images of the species over several years. They measured the tails and bodies in each image to come up with a percentage of the tufted ground squirrel's tail volume relative to its body size and came up with a whopping figure - 130 percent.

Publishing their findings in the journal Taprobanica, they list ring-tailed cats (Bassariscus as tutus) from North America, common striped possums (Dactylopsila trivirgata) from Queensland in Australia, and squirrel gliders (Petaurus norfolcensis), also from Australia, as equal second in the bushy tail stakes, will a tail volume relative to body size percentage of 100 percent.

So the tufted ground squirrel wins, but the question remains, why do they need such ridiculous fluff in the first place?

"A relatively large body size and terrestrial habits requires effective defence against terrestrial predators, such as the sunda clouded leopard (Neofelis diardi). It may well be that the very large, fluffy tail of Rheithrosciurus is an anti-predator mechanism,” the team concluded.

"In flight, the grey tail, which consists mostly of long fur, obscures the actual body of the animal. This could either confuse a predator in pursuit, or if the predator would pounce on the squirrel it would most likely strike at the tail, which would provide a predator with limited hold. This hypothesis needs to be supported by more detailed behavioural observations before it can be accepted, but it seems the most logical explanation of the Rheithrosciurus’s extravagant tail."

Bec Crew is a Sydney-based science writer and award-winning blogger. She is the author of 'Zombie Tits, Astronaut Fish and Other Weird Animals' (NewSouth Press).

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