ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)

[GuateGojira]

(07-05-2015, 09:43 AM)'Richardrli' Wrote: I think some areas of the Asian mainland does contain significant geographical barriers, like the Himalayas and Gobi. What is the historical distribution of tigers in Mongolia? I wouldn't think there was too many tigers there though I know for sure that they existed at some point.

 

This map from Kitchener & Dugmore (1999) show the records of tigers from Mazák (1996). There were tigers in Mongolia, but in the northern region.

*This image is copyright of its original author

It clearly show a gap between Caspian an Amur tigers and an unclear border between the South China and the Amur tigers. However, we most remember that at those days (1999) no genetic study was available and the new documents from Driscoll et al. (2009) evidence that the separation between the Caspian and the Amur tiger (the gap in the map) was just about 200 years, and I think, based in that same map, that the supposed tigers in the frontier of the subspecies Amur-Amoyensis were probably transient ones, as very few records existed in that area (on 5 and very separated).

Check the image from Driscoll et al. (2009):

*This image is copyright of its original author

Figure 1. Range of the tiger Panthera tigris: Historical range of tiger distribution is shown in light tan and current range is shown in dark tan, while green dots indicate individual historical recordings of tigers outside of normal distribution [1]. Green ‘dot’ indicate records from the Middle Ages [4]. Black lines demarcate presumed subspecies boundaries [3]. Abbreviations correspond to traditionally named tiger subspecies, arranged chronologically by date of naming. 1) tigris Linnaeus, 1758[37]; 2) virgata Illiger, 1815[38]; 3) altaica Temminck, 1844[39]; 4) sondaica Temminck, 1844[39]; 5) amoyensis Hilzheimer, 1905[40]; 6) balica Schwarz, 1912[41]; 7) sumatrae Pocock, 1929[42]; 8) corbetti Mazak, 1968[43]; 9) jacksoni Luo et al., 2004[11]. Lettered arrows indicate postulated dispersal avenues: (A) Indian, southern route; (B) Siberian, northern route; and (C ) Silk road/ Gansu route with (D) secondary eastward dispersal. See text for details. Redrawn from Figures 19 and 20 in Mazak [1] and Figure 1 in Kitchener and Dugmore [3].

Taking this in count, we can state that about 10,000 - 12,000 years ago, two great invasions succeeded in enlarge the tiger habitat, thanks to the climatic change and the end of the ice age. This change changed the old savanna type habitats in to forests, which are necessary for tigers. The first wave was to India, which succeeded in create the Bengal tiger population, the other was to the north creating the Caspian tiger and latter the Amur one. However, the habitat in India was way richer than that of the north and the population of tigers established it best population. Meanwhile, the Caspian tigers lived tied to the water sources and the constant human influence in those hard climates areas finally affect them, separating the main population from the southern Asia tigers and creating this "new" clade of the north.

At the end, it seems that all make sense, one mainland subspecies separated in two clades by the deserts, high mountains and most importantly, the human intervention. That is why Caspian tiger skulls overlap greatly with the Amur and the Indian-Indochina-China tigers, but the Amur and the Indian tigers are very different.
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