In what groups we can divide the Bengal Tiger?

[GuateGojira]

This is a good question, one that deserves an answer.

From my point of view, there are different approaches in this subject, like the morphological, the habitat differences and the human intervention.

1. Morphology:
From a morphological point of view, I have saw so many measurements and types of coats to say that I don't see too much differences between the populations. Fore example, I have saw Ranthambore tigers with coats that can be confused with Amur tigers and the same phenomenon is seen in the winter at Nepal and Buthan. South India tigers do not have this variations, but still they behavior is the same, and there is no difference between them and the summer coats of the northern tigers.

Popularly is stated that Northern tigers are the biggest and Southern ones are the smallest, but this is not accurate at all. In fact, the skulls that are normally quoted are scanty and sample sizes are even lower than those of weights and lengths, so to create a conclusion based in two or three skulls, like Pocock (1939) done, is dangerous. In body terms, Tigers from the Terai arc, Assam, Central and southern India are of the same size, which is between 260 - 310 cm in total length and all these populations reach the weights of 160 - 260 kg, the same case apply with the females with similar ranges. The exception is with the south east of India, with those of Hylderabad, but the terrain is somewhat different there and probably affected them size development (weights of no more than 203 kg are reported).

The Sundarbans tigers are the exception of all, with sizes and weights in the range of the Sunda tigers, however this change is very early and caused by human intervention. Old records from this area shows less than 5 specimens, but all of them fit in the range of the other mainland tigers. The shrinkage of this population is a reflect of the changes made by the humans in its habitat.

2. Habitat:
The Indian subcontinent is a magnificent mosaic of climates, terrains and prey diversity, tigers evolved its best form in this continental treasure. Despite the differences in climates, again it seems that the differences between the main populations of the Terai arc, Central and South west India are about the same, taking in count also the differences in prey densities and varieties. Sundarbans is again the black dot in the white page, been the only tiger population that lives in mangroves and with such a low prey density.


3. Human intervention:
I think that this is the main reason of the modern "differentiation" of the populations in the Indian Subcontinent. In the old days, the tiger populations were contiguous and were not natural barriers. After the growth of the human population, the tiger groups were slowly fragmented and diminished at his modern numbers. The most affected is the one of Sundarbans, which are genetically related with Central Indian tigers, but with the habitat type, its isolation and the very small size of the prey, changed into a very small form.

I remember one shocking thing about the origin of the Ranthambore tigers, which according with Valmik Thapar, are the result of a group of reintroduced specimens that came from the region of Gwalior. I am going to search the page and the book were he said this. This means that some "populations" are already intermixed since many years.


Well, this is a very quick analysis, but with more information I can go deeper. For the moment, my "classic" differentiation of the Bengal tigers has been:

1. Northwest population (West Terai arc region).
2. Nepal (Central Teria region).
3. Northeast population (East Terai arc region).
4. Central India.
5. Southwest India (Western Ghats region).
6. Southeast India (Hyderabad region).
7. Sundarbans.


However, with more information and data, my classification is going to change and it will to be reflected in the new tables.

These are my two cents. Greetings to all. Reply