Indian Giant Squirrel - Subspecies

Subspecies

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.

The different subspecies lists are indicated in the table below, along with some of the corresponding references supporting each one:

To further complicate things, there is yet still more disagreement about the classification of this species' subspecies. Some biologists maintain that there should be up to eight subspecies considered, due to the fact that there are eight different distinct color schemes found among this species, and these are based on geographical ranges with intervening areas that separate the squirrel populations from one another.

Finally, there is still another point of disagreement in which some biologists consider that some of these subspecies ought to be elevated to be considered their own species. In this case, the general agreement would be that there would be four or five species created out of Ratufa indica's subspecies.

To sum this up, this species either has three, four, five or eight subspecies, or it may end up having none. This irresolution has been going on for over a century, and there is no indication that it will be resolved anytime soon. It is important to note, when dealing with this species, that there is this disagreement, and even if it is resolved in the future, there will still be much confusion within the literature that has already been published. So, it is good to keep this in mind when reading or studying this species, in order to avoid potential confusion.

Here are some brief descriptions of some of the color schemes and subspecies:

• Ratufa indica indica (Erxleben, 1777)
• The rust and buff Ratufa indica centralis (Ryley, 1913) of the tropical dry deciduous forests of Central India, near Hoshangabad.
• The buff and tan Ratufa indica dealbata (Figure 1, top) of the tropical moist deciduous forests of the Surat Dangs.
• The seal brown, tan, and beige (and darkest) Ratufa indica maxima (Schreber, 1784) (Figure 2, bottom) of the tropical wet evergreen forest of Malabar.
• Ratufa indica superans (Ryley, 1913)
• the dark brown, tan and beige (and largest), Ratufa indica bengalensis (Blanford, 1897) (Figure 2, top) of the tropical semi-evergreen forests east of the Brahmagiri mountains in Kodagu extending up to the Bay of Bengal coast of Orissa;
• It is also seen (dark brown) on Tirumala hills at Tirupati both in the wild and at Sri Venkateswara Zoological Park, Andhra Pradesh.

The table below lists the four recognized subspecies (based on Thorington & Hoffmann 2005) of Ratufa indica, along with any synonyms associated with each subspecies: