Jentink's Squirrel

Fascinating facts about the Jentink's Squirrel

• Jentink's squirrel vanished from science for 120 years. In 1892, a single specimen was collected from Borneo's rainforest and stuffed into a museum drawer. Then nothing—no sightings, no photographs, no proof it was still alive. When a living squirrel was finally spotted again in 2012, scientists realised they'd been searching for a ghost that was never confirmed extinct. It revealed how little we know about the rainforest canopy 40 metres above us.
• At 130 grams—lighter than a deck of cards—Jentink's squirrel is one of Southeast Asia's smallest tree squirrels, yet it navigates Borneo's tallest dipterocarp trees like a parkour athlete. Its tail curves up and over its back for balance while leaping across gaps wider than a dining table, a manoeuvre only possible because it weighs almost nothing. This miniature size is the animal's passport to the upper forest layers where larger squirrels cannot venture.
• The squirrel's diet tracks the moody schedule of Borneo's fruit trees, which fruit unpredictably every 2 to 8 years in synchronized bursts called mast fruiting. When the forest explodes with seeds and fruits, Jentink's squirrel caches thousands of them in tree cavities and soil—a single squirrel can bury enough to feed itself for months. If it remembers where even 70% of its hiding spots are, the forgotten seeds become seedlings that reshape the forest's future.
• For a century Jentink's squirrel hid so successfully that museum labels and field guides didn't even have a name for its appearance. Researchers knew only a black silhouette from old taxidermy. Living specimens photographed after 2012 revealed it wears a bright russet-red belly and limbs—a colour pattern that makes perfect sense in dappled canopy light but had never been recorded in scientific literature until the animal stepped out of the dark.
• Jentink's squirrel exists only in Borneo's remaining old-growth rainforest—a habitat shrinking by 0.4% each year, meaning the island loses about 30,000 hectares annually. The squirrel's rediscovery came just as Borneo's forests hit a critical tipping point, where the loss accelerates. This animal's survival depends entirely on whether humans can halt deforestation at a scale they have not managed anywhere else on Earth.

At a glance

About the Jentink's Squirrel

In the lush, emerald canopies of Borneo's ancient forests, the Jentink's Squirrel dances through the trees with an effortless, weightless grace, its rust-hued fur blending seamlessly into the dappled light. As it leaps from branch to branch, its long, slender body undulates like a living, breathing ribbon, weaving a mesmerizing path through the intricate network of twigs and leaves. With each nimble bound, this arboreal acrobat embodies the very essence of its jungle realm, a testament to the beauty and agility that thrives in these vibrant, verdant worlds.

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