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

[peter]

BIG CATS IN JAPAN

After responding (see post 1,669) to the question of Tigerluver (see post 1,668), I reread the first pages of this thread. Posts 06 - 16 - 17 - 58 - 65 - 66 - 68 have information about big cats in Japan. I also reread an article about the distribution of tigers in the Pleistocene and Holocene.

The points that stuck are briefly discussed in this post.

a - Japan most probably had tigers about 20 000 years ago

In 2016, 'Predicted Pleistocene-Holocene Range Shifts of the Tiger (Panthera tigris)' was published in 'Diversity and Distribution'. This article (Cooper DM - Dugmore AJ - Gittings BM - Sharf AK - Wilting A - Kitchener AC) is of interest regarding Japan.

Here's the link to the (full) article (recommended): https://onlinelibrary.wiley.com/doi/full/10.1111/ddi.12484

In the article, 3 distribution models were discussed. In all of them, the presence of tigers in Japan is predicted:

*This image is copyright of its original author

*This image is copyright of its original author

b - The skull excavated in Japan, most probably, didn't belong to Panthera tigris, but to Panthera palaeosinensis

After Zdansky's publication on Panthera palaeosinensis (1924), this Early Pleistocene jaguar-sized big cat was seen as the initial model of Panthera tigris for quite a long time:

*This image is copyright of its original author

Later, this conclusion was revised. Panthera palaeosinensis now is regarded as an early representative of the genus Panthera:

https://prehistoric-fauna.com/Panthera-palaeosinensis

I don't know if the skull excavated in Japan a century ago (referring to the photograph in post 1,668) belongs to P. palaeosinensis or P. tigris, but the photograph suggests the last.


c - If the previous points both are correct, Japan could have had two species of big cats

It is not known when Panthera palaeosinensis became extinct in Japan. Based on what I read, it's likely this cat disappeared between 100 000 - 80 000 years ago.

I'm not sure if the Toba eruption (about 75 000 years ago) had a direct effect on big cats in northeastern Asia (tigers survived in southeastern China), but it's likely that the animals they hunted were affected (referring to the effect of climate change on vegetation).

After the population had recovered, tigers recolonized most of northeastern and western Asia. The article discussed above says Japan was included.  

During the Holocene, when the sea level rose, Japan, like Indonesia, was isolated from mainland Asia. It's likely that Panthera tigris (japonensis), as Grizzly suggested, had to adapt to new conditions. Losing size can help, but a big cat surviving on smallish mammals will struggle with an energy deficit in the long run, especially in severe winters. If we add human pressure, chances are they didn't survive more than a few thousand years.       

Indonesia had no winter. It did have a lot of forest and many medium-sized and (Sumatra) largish prey animals. Human pressure was low for a very long time. This is why tigers were able to adapt and hold on in Sumatra, Java and Bali. In Palawan and Borneo, they did not. I'm not sure about Palawan, but Borneo has no large mammals to hunt. 

When the human population exploded in Indonesia, the countdown for tigers started. Bali tigers were the first to go. Java tigers most probably perished a few decades later. Sumatra still has pristine forests and 300-900 tigers, but the natural world is rapidly disappearing and conservation has no priority. Reply