Squirrels have been around on Earth for around 30-40 million years, and around 200 species have been identified worldwide. Endearingly inquisitive and remarkably agile, they come in various forms. Tree squirrels, ground squirrels, chipmunks, marmots, flying squirrels, prairie dogs — all of them present in the wild on every continent except Antarctica and Australia.
Squirrels are currently classified into five subfamiles: Ratufinae, Sciurillinae, Sciurinae, Xerinae, and Callosciurinae. The forests of south and southeast Asia host four cat-sized tree squirrels belonging to the genus Ratufa — the black giant squirrel (Ratufa bicolour), the Indian giant squirrel (Ratufa indica), the grizzled giant squirrel (Ratufa macroura) and the pale giant squirrel (Ratufa affinis). The first three are found in India.
Giant squirrels are among the largest squirrels in the world. These arboreal creatures prefer habitats with contiguous forest patches, tall trees, and canopy connectivity, which protect them from predators and provide an ample supply of food. In fact, they rarely descend from the forest canopy. Despite their high perch they serve as prey for raptors and sometimes even large carnivores such as leopards and clouded leopards and primates such as lion-tailed macaques.
Giant squirrels weigh between 1.5 and 3 kilos, and have tails that are as long as their bodies, measuring 25-46 cm. Just like other members of the order Rodentia, they are endowed with two front teeth that continue to grow throughout their lives. They primarily feed on fruits, flowers, seeds, leaves, bark, and occasionally insects and bird eggs too.
Scientists don’t know why these mostly solitary giant squirrels evolved to be larger than their squirrel cousins. Biologist Nandini Rajamani suggests their larger size might enable them to access different kinds of food from different storeys of the forest.
Destruction and fragmentation of their forest habitats, along with hunting, are major threats to the survival of giant squirrels.