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

[peter]

THE HISTORY OF AMUR TIGERS

A - Research

The bones described by Baryshnikov prove that the Russian Far East had tigers in the Late Pleistocene. According to Baryshnikov, these tigers were not very different from the recent tiger living in that region, P. tigris altaica. Genetic research (driscoll et al., 2009) revealed that P. tigris altaica and P. tigris virgata are just about one and the same. This means that the Russian Far East was colonized by Caspian tigers moving east. According to Kitchener and Dugmore, Caspian tigers only migrated to the Russian Far East in the Holocene. In that period, China tigers also moved to northern Asia.

So what do we have? 

B - A few preliminary conclusions

01 - The bones from the caves suggest there was not much difference between Late Pleistocene tigers and recent tigers in the RFE.
02 - We know that Amur tigers and Caspian tigers are almost identical. 
03 - Based on -01- and -02-, the conclusion is that the Late Pleistocene tigers in the Russian Far East were Caspian tigers.
04 - Kitchener and Dugmore, however, concluded that Caspian tigers only migrated to the Russian Far East in the Holocene.

Something is not right, that is. Here's a few hypotheticals. 

C - Ideas

05 - Caspian tigers in the RFE colonized the RFE in the Late Pleistocene (a) and in the Holocene (b).
06 - If -05- is correct, Kitchener and Dugmore were not.  
07 - Unless (see -06-) the tiger population in the RFE disappeared in the Late Pleistocene and the RFE was recolonized in the Holocene.
08 - If -07- is correct, the RFE had to be recolonized in the Holocene by the same tigers living in this region in the Late Pleistocene. 
09 - As -08- seems very unlikely, we have to assume that Kitchener and Dugmore were wrong for now.
10 - Unless (see -09-) northern Asia was colonized by Amur tigers moving west. 
11 - Which (see -10-) is unlikely, as the genes of Caspian tigers show more 'age' than Amur tigers.
12 - Based on 01-11, we have to assume that the RFE was colonized by Caspian tigers in the Middle Pleistocene and in the Holocene.

D - Japan, Korea and northern China 

Based on what I have, I'd say that Korean tigers were not very different, if at all, from Amur tigers. A bit smaller perhaps, but Korean tigers lived on the edge (sea on three sides) and tigers living on the edge often are smaller than tigers living in other regions. Most of Korea is quite similar to the RFE. This means that Amur tigers moving east and south might have colonized Korea in the Holocene without much problems, when Japan became isolated and Japan tigers disappeared completely.

And what about tigers in northern China moving to northern Asia in the Holocene? This is a bit of an enigma. It's likely that some individuals reached the Altai Mountains and the region east of Lake Aral, where they would have met with P. tigris virgata. Manchuria, a sea of forest in that period, would have been more suited to tigers. So suited, in fact, that it would have been a true tiger paradise. Every now and then, during a crop failure when wild boars moved north, some Manchurian tigers would have followed them but it is unlikely they settled in northern Asia for lack of opportunities. Wild boars nearly always returned to the sea of forest down south.

E - Amur tigers and Manchurian tigers

My guess is there were outspoken differences between tigers living in northern Asia (the Caspian region, the Altai Mountains, northern part of Mongolia, the RFE and Korea) and Manchurian tigers (and tigers in northern China in general). The first type was, and still is, quite long and tall but not as heavy as a tiger of similar size living in a food hotspot, whereas Manchurian tigers, also large, were true forest cats living in a region of plenty. Manchurian tigers, also facing severe cold every winter, always had more resources. For this reason, size was a good option. Manchurian tigers might have compared to tigers living in similar regions in India today; large and robust.

Amur tigers, in spite of quite a few years of protection and a significant increase in numbers, still have very large territories. The reason is a lack of large prey animals. Amur tigers need to learn how to deal with energy deficits, hills and competition. We can't exclude the occasional giant, but my guess is a large size would be a disadvantage in a region with harsh living conditions. In a way, Amur tigers, although isolated, compare to Himalayan tigers, also long, tall and large. My guess is that Himalayan tigers are larger and heavier for the simple reason they have more access to large prey animals. Plenty is not a result of coincidence in that region. In the RFE, its most certainly is.   

F - Panthera tigris acutidens

And what about the descendants of P. tigris acutidens? Could they have survived the consequences of the Toba eruption and mixed with P. tigris virgata at some stage, in this way securing their genes? My guess is they did.

I've seen many captive tigers and concluded that Amur tigers are very different. It shows in many ways. The skull is more elevated, longer and more primitive. The body is different as well. As soon as they get the chance, captive Amur tigers, and males in particular, produce a size hardly ever seen in other subspecies. All other subspecies, including Manchurian tigers, produce large and bulky individuals in exceptional conditions, but Amur tigers, even when very large, nearly always combine power with athleticism. In their winter coat, males may seem to be bulky or even fat, but in most cases it's deceptive.

Captive Amur tigers seem to be docile and social animals. Quite often, they are. When they lose their temper, however, they produce something I never saw in other big cats. More than once, I thought an enraged male would demolish his cage. I never was the only one who thought so, but I usually was the only one who stayed. It's a kind of energy difficult to describe. A century ago, in Korea, Manchuria and the RFE, Amur tigers searched for mates in winter. The sounds of fighting males during a frosty night unnerved many hunters. Some left the scene during the night, never to return. Others had to be hospitalized. 

We now know that Amur tigers hunt and sometimes fight bears of near-similar size. We take it for granted, but it's not. Bears are very powerful and agile animals that can take a lot of damage. Killing a bear is not easy and a fight is very risky for any tiger. I'm not saying that Amur tigers hunt bears on a regular basis, but research says it's close in some parts of the RFE, especially in summer and autumn. Living with bears is not easy for any big cat. Hunting them even less so, let alone engage them. Nearly all wild Amur tigers need to be experienced in this respect. It's something that sets them apart. In order to get an idea, read interviews with trainers. Bears usually are more dangerous than big cats.
          
Could the behaviour regarding bears be a result of something from the past, or are Amur tigers no different from other subspecies? One could make a case for the second option, but I thought I saw something from a period in which humans didn't really participate. Reply