Known for its remarkably large tail, the tufted ground squirrel (Rheithrosciurus macrotis) has a surprisingly unconventional diet, even considered the most savage squirrel on Earth. Not without reason, this squirrel consumes meat by pouncing on its prey.
This unique creature originates from the mountainous forests of Kalimantan, and although its evolutionary history is still shrouded in mystery, scientists are currently working to unravel the role and origin of this distinctive tail.
As a rodent, the tufted ground squirrel is a source of awe and wonder, largely because of its unicorn-like tail, which accounts for up to 30% of its body volume. Formerly known as "vampire" squirrels, they were thought to be carnivorous predators, inspiring folktales and local anecdotes about their deadly hunting skills against deer and birds.
A scientific study in 2014 revealed that the tufted ground squirrel would leap from low branches onto the back of a deer, slashing the veins in its neck with its sharp teeth. Local Dayak hunters reported discovering deer carcasses dissected by these squirrels, suggesting that they enjoy the contents of their prey's stomachs, hearts, and livers. In villages near the forest edge, there are also reports of ground squirrels killing domesticated chickens for their hearts and livers.
However, a recent study suggests a different dietary pattern for ground squirrels, changing their image from fierce predators to seed specialists. They use uniquely structured teeth to handle extremely hard seeds, challenging even human hammering skills. In a surprising reversal of history, these teeth once thought to be hunting weapons, turn out to be specialized tools for accessing vital nutrients in these tough seeds.
With tails comprising about 30% of their bodies, tufted ground squirrels have one of the largest tails relative to body size among mammals. Although the reason for their lavish tails remains unclear, it is likely a means of self-protection from predation, possibly by confusing potential predators with the oversized tail obscuring their small bodies, especially against threats like the Sunda clouded leopard.
The evolutionary path of ground squirrels remains a mystery, especially since their closest relatives are found in South America, with no clear path to their current home in Asia. The lineage of these squirrels is thought to have diverged more than 36 million years ago, implying a journey from the Pale Arctic to Southeast Asia. The mystery of the tufted ground squirrel continues, providing an opportunity to further explore the wonders of nature and understand the complexities of a unique ecosystem balance that harbors evolutionary stories waiting to be unraveled.