Indian Giant Squirrel

As can be seen in the range map of this species, it occupies isolated ranges that are widely separated from each other, thus producing conditions favorable for speciation. The squirrels found within each of these isolated ranges share distinctive color schemes, making it easy to identify which region a particular squirrel is from, as well as leading to the controversy as to whether these different color schemed subspecies ought to be considered as unique species.
There is some disagreement between biologists regarding how many subspecies belong to the Ratufa indica lineage. It is generally acknowledged that there are either four or five subspecies, depending on the source. This discrepancy is based on two separate lines of research, dating back to the 18th century. However, the most current data indicates that one of the subspecies (R. i. dealbata) claimed by those supporting the four subspecies stance has disappeared from its range in the province of Gujarat. Subsequently, it could also be argued that there are only three subspecies remaining.