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Apex Titan · 02-28-2025, 06:48 PM

(02-28-2025, 06:31 AM)peter Wrote: APEX

Yet another long, well-prepared and interesting post about tigers and bears in the Russian Far East. Must have taken quite a bit of time. Effort much appreciated!

I assume you're aware of the video about interactions between tigers and bears in the Russian Far East recently uploaded on YouTube by Prof. S. Wroe? I made a few notes and will discuss it in some time:

https://www.youtube.com/watch?v=_mcKIpZW9qs

In his video, Prof. Wroe discusses three issues also often discussed at forums: size, bite force and reliable reports about the outcome of interactions.

Although the info on size seems a bit outdated (he uses information collected in the period 1992-2002 or thereabout), it's reliable.

Most adult male Amur tigers today, depending on their condition and the season, range between 360-442 pounds (163,3-200,5 kg). Both Batalov and Fomenko said a male exceeding that mark (442 pounds or 200,5 kg) is large in most districts. Adult male Ussuri brown bears, depending on the district and the season, average 575-595 pounds (260,8-269,8 kg).

Individuals well exceeding these markers (referring to both species) have been weighed, but they're few. For now, it's safe to assume an exceptional wild male Amur tiger can reach 270 kg (596 pounds, Feng Limin), whereas an exceptional male Ussuri brown bear can reach 362,88 kg (800 pounds, WCS).

According to Wroe, who knows a few things about bones, the bite force of tigers exceeds that of brown bears by about 20%. The percentage, as Warsaw stated, is questionable, but it isn't about the details. What Wroe is saying is tigers, biteforcewise, have an advantage. That's still without the canines. If we add speed and agility, one could conclude an average adult male Amur tiger roughly compares to a larger male brown bear in most respects. Tigers and brown bears seem to agree. The result is mutual avoidance.

Some male bears follow and rob tigers, but they tend to select females (with cubs) and, perhaps, (young and/or old) males with problems. And the other way round: experienced male tigers interested in bears, as you stated, tend to select female brown bears up to about their own size (weight). The recent incidents discussed in this thread strongly suggest male brown bears are sometimes hunted as well. All in all, one could conclude Amur tigers are quite prolific bear hunters, not the other way round. Russian biologists did find overwhelming evidence of tigers killed by brown bears, but not in the period 1992-2025.

Prof. Wroe's video didn't go unnoticed. I recently visited 'Domain of the Bears' and 'Carnivora' and noticed Warsaw is preparing for battle. You can have a go at prof. Wroe's video if you like, but when you post about it in this thread make sure you focus on information, not something else.

At the moment, I'm investing most of my energy in skulls and conflicts (between man and tiger). I recently found a video in which a young adult male features. He was shot (by poachers) and, most unfortunately, perished. Another male, adult but still quite young (referring to the teeth), was injured in a fight. He needed medical assistence and was sent to rehab.

Yes, I saw Prof. Wroe's video over a week ago. Its a good video, but he solely focused on information and studies published about tiger-bear relations during the period 1992-2012 (WCS & Tkachenko). There's plenty more recent information, data, and accounts of tiger predation on brown bears he never mentioned in his video. There's more recent studies, accounts, and even videos he could have presented.

Interestingly, Prof. Wroe, a specialist in bite forces and skull morphology of mammalian carnivores, said: "We found that a 177 kg tiger can exert a bite force at the canine teeth that is around 20% more than that of a 355 kg polar bear, more than twice its own size" ("Bite Forces and Evolutionary Adaptations To Feeding Ecology In Carnivores", Per Christiansen & Stephen Wroe).

Undoubtedly, as I've also mentioned several times in my previous posts, even a medium-sized tiger's bite is far more devastating and lethal than even a significantly larger male brown bear or polar bear's bite. Not to mention, the tiger's much longer, thicker, and sharper canines which penetrates much deeper than a large male brown bear's much smaller and blunter canines.

Prof. Wroe's video, uploaded a month ago, definitely needs an update on Amur tiger-Brown bear relations/information. And I think he would definitely agree.

However, when I read the comment section, I saw that Professor. Wroe is now aware of the account of Odyr hunting and killing the large adult male brown bear. He mentions this case in the comment section 5-6 days ago. ( I'm not "Heaven-dy9lj", this was a random youtube user talking to the Professor ):

*This image is copyright of its original author

return 80 · 03-01-2025, 04:23 PM

Late Pleistocene tiger fossils from the Shiriyazaki on the Shimokita Peninsula northern Honshu, Japan

This is a comparative report on Shiriyazaki's Japanese Late Pleistocene tiger fossils published last year.Although many previous reports on Japanese tiger fossils were very small, the tiger fossils collected in this report are all very large, with an overall size equivalent to that of male Amur tiger, and even some individuals significantly larger

*This image is copyright of its original author

Fossils were collected from different locations in Shiriyazaki, involving dental materials and limb bone materials. I have selected some materials to discuss, and more materials can be found in the original text:

<下北半島尻屋崎地域産トラ化石>
Bull.Gunma Mus.Natu.Hist.（28）：45－64, 2024.

1.Comparative materials

The comparative material is an elderly male Amur tiger, born in Germany in 1992. The male Amur tiger was kept in Hamamatsu Zoo(浜松市動物園) from 1995 to 2010 at the age of 18. The cause of death is believed to be related to
lymphadenopathy. "Name: ルー(Lu), International Lineage Registration Number: 3920

*This image is copyright of its original author

This individual has a very large skull(380mm×284mm) and an overall limb bone length comparable to other male Amur tiger individuals (Tiger-04, AMNH85404, AMNH85396,M.S.241/M.S.242).

2.Upper canine

These three canine teeth are all very large. The translation of the relevant measurement indicators:
全長=total length
歯冠前後径=anteroposterior diameter of crown base
歯冠頰舌径=lateromedial diameter (buccal lingual side) of crown base
歯冠高さ（頰側）=crown height (buccal)
歯根最大前後径=maximum anteroposterior diameter of tooth root
歯根最大頰舌径=maximum lateromedial diameter of tooth root

*This image is copyright of its original author

The main text does not provide a comparison between them and Amur tigers. Here, I use Boneclones' Amur tiger skull as a substitute for comparison. The measurements are shown below

歯冠前後径:26.9mm(L) 26.6mm®
歯冠類舌径:20.4mm
歯冠高さ（頰側):58.9mm(L) 58.3mm®

I don't have root measurement data for male Amur tigers, but considering they are larger than the largest root measurement data (31mm) among dozens of male South African lions in Smuts' article[<Age determination of the African lion (Pantheva leo) >], their size is indeed very large.The relatively small crown height may be due to individual developmental differences and taphonomy influences (see figure), and overall, these canine are undoubtedly the size of male Amur

*This image is copyright of its original author

Other premolar materials show individual variations in the development of the anterior cusp and the boundary morphology of the labial and buccal sides, with overall measurements similar to those of Amur tigers

3.Appendicular skeleton

In terms of overall size, these tiger appendicular bone fossils are almost the same size as those of "ルー", with only a few individuals slightly smaller (such as NMNS9621).But many Appendicular skeleton elements, such as the femur, are proportionally more robust than "ルー", which may be due to the lack of activity in captive individuals.

Impressively, there is a large incomplete humerus and it's maximum distal width(内顆・外顆間の幅) is 97mm.The lateromedial diameter and anteroposterior diameter at the end of the deltoid crest are 35mm and 43mm, respectively, and the bone is very thick and robust.

*This image is copyright of its original author

There is a record of a very large tiger humerus in Gross 1992, with a maximum length of 373mm and a maximum distal width of 96mm, almost the same width as this incomplete humerus.And a robust watualang tiger humerus(NM1933,353mm greatest length and 99mm distal width ) also have the similar width.

There is another extremely large individual worth mentioning:NMNS25891(5th metatarsus).

*This image is copyright of its original author

The measurement values of all aspects of this Mt5 material are larger than "ルー", and the difference in length is more significant (132vs118). its overall size should be comparable to the elderly male cave lion in Siegsdorf (132.5mm, Gross 1992:127). Specifically, this cave lion is a medium-sized individual of the Late Pleistocene European cave lion.

Summary

The tigers in this region during the late Pleistocene were very large, with an overall size similar to that of male Amur tigers, and some individuals slightly smaller, possibly due to sexual or individual differences (size differences are not particularly significant compared to "ルー").

There are also some very large individuals among them, whose Appendicular skeleton elements are much larger in size than the normal male Amur tiger, reaching the size of a medium-sized cave lion.It is worth noting that there are also reports of giant wolf and brown bear fossils in this area

return 80 · 03-02-2025, 07:40 PM

The SOB and OH of tigers

The Supraoccipital breadth(SOB) relative to the Occipital height(OH) In previous studies, it was considered a significant distinguishing feature between different subspecies of tigers, and even now it has at least valuable population identification significance.

*This image is copyright of its original author

In tigers, the relative width of SOB can be clearly defined as gradually increasing from south to north on the Asian continent, which seems to be a functional adaptation caused by their corresponding ecological environment.

*This image is copyright of its original author

However, there does not seem to be much data on SOB in the literature, and it is generally not a major measurement value.

Its measurement method is"the smallest distance between notches of lateral margins of the occiput; the notch being situated approximately where sutura occipitoparietalis, sutura parietotemporalis and sutura occipitotemporalis meet"(Ji H. mazák 2008)

I have seen a good structural diagram(see blow, Narimane Chatar et al.2022) that can clearly distinguish these bone sutures. Please pay attention to the intersection of the occipital and parietal and the temporal in the diagram.

*This image is copyright of its original author

In the posterior view provided by Ji H. mazak, the specific location is the highest point on the dorsal side of the mastoid process And the Dorsal view can be seen in Figure B. Búzás and B. Farkas 1996.

*This image is copyright of its original author

In the publications of V. mazák and Ji H. mazák, it seems that I can only find specific data on island tigers and indochinese tigers (including Malayan tigers)

*This image is copyright of its original author

However, in his publication<Recent Advance in Tiger Phylogeny, In the Evolution and Geographical Variation >(Chinese version), he listed the scatter plot data of male SOB for all subspecies.

*This image is copyright of its original author

According to the scatter plot, we can see that the Amur tiger has a significantly widest SOB, both in terms of relative width and absolute width.Corresponding to the logarithmic axis of SOB, the SOB of some particularly wide male Amur tiger individuals may even reach around 90mm, almost 1.8 to 2 times that of some small Java and Bali tigers.

One of the male Sumatran tigers is very interesting, with a maximum recorded SOB of 83.4mm. Such a huge size makes it easy to find in scatter plots. From the graph, it can be seen that its SOB is almost as wide as the widest male Bengal tiger and comparable to many male Amur tiger individuals, which is very astonishing.

Apex Titan · 03-06-2025, 08:06 PM

@peter

Professor. Wroe, in his video, showed this picture of the skull of an Asiatic black bear that was killed by a tiger.

An Amur tiger with broken canines killed an Asiatic black bear by crushing its skull with the stubs of its canines, reported by Tkachenko. This highlights the devastating bite force of a tiger, and shows that tigers, with broken canines, can even kill bears by destroying their skull.

Some years ago, I also saw pictures of the skull of an Ussuri wild boar that was killed by a tiger who crushed the boar's skull with a bite. There's no doubt, that in some cases, tigers do kill bears and wild boars by crushing their skulls with a lethal bite.

Asiatic black bear skull crushed by a tiger (Tkachenko):

*This image is copyright of its original author

return 80 · Yesterday, 03:54 PM

(03-02-2025, 07:40 PM)return 80 Wrote:
The SOB and OH of tigers

The Supraoccipital breadth(SOB) relative to the Occipital height(OH) In previous studies, it was considered a significant distinguishing feature between different subspecies of tigers, and even now it has at least valuable population identification significance.

*This image is copyright of its original author

In tigers, the relative width of SOB can be clearly defined as gradually increasing from south to north on the Asian continent, which seems to be a functional adaptation caused by their corresponding ecological environment.

*This image is copyright of its original author

However, there does not seem to be much data on SOB in the literature, and it is generally not a major measurement value.

Its measurement method is"the smallest distance between notches of lateral margins of the occiput; the notch being situated approximately where sutura occipitoparietalis, sutura parietotemporalis and sutura occipitotemporalis meet"(Ji H. mazák 2008)

I have seen a good structural diagram(see blow, Narimane Chatar et al.2022) that can clearly distinguish these bone sutures. Please pay attention to the intersection of the occipital and parietal and the temporal in the diagram.

*This image is copyright of its original author

In the posterior view provided by Ji H. mazak, the specific location is the highest point on the dorsal side of the mastoid process And the Dorsal view can be seen in Figure B. Búzás and B. Farkas 1996.

*This image is copyright of its original author

In the publications of V. mazák and Ji H. mazák, it seems that I can only find specific data on island tigers and indochinese tigers (including Malayan tigers)

*This image is copyright of its original author

However, in his publication<Recent Advance in Tiger Phylogeny, In the Evolution and Geographical Variation >(Chinese version), he listed the scatter plot data of male SOB for all subspecies.

*This image is copyright of its original author

According to the scatter plot, we can see that the Amur tiger has a significantly widest SOB, both in terms of relative width and absolute width.Corresponding to the logarithmic axis of SOB, the SOB of some particularly wide male Amur tiger individuals may even reach around 90mm, almost 1.8 to 2 times that of some small Java and Bali tigers.

One of the male Sumatran tigers is very interesting, with a maximum recorded SOB of 83.4mm. Such a huge size makes it easy to find in scatter plots. From the graph, it can be seen that its SOB is almost as wide as the widest male Bengal tiger and comparable to many male Amur tiger individuals, which is very astonishing.

The two posts I previously posted only explained some phenomenon reports, but did not provide content explanations. Indeed, this is very necessary, so here I share some of my views

Although Hasegawa has reported multiple tiger fossils sites from Japan, unfortunately, these materials have not been systematically organized, so I can only provide some speculations on why Shiriyazaki's Late Pleistocene tigers were so large.

*This image is copyright of its original author

According to the ecological geographic model of tiger populations by Luo et al. 2024(https://doi.org/10.1038/s41559-023-02185-8), we can see that during the LGM (Last Glacial Maximum,Fig.B), Japan was connected to the Asian continent due to sea level decline, and at this time, Japan was also a high probability habitat suitable for tigers (red area).

Some of tigers may have migrated from China to Japan, and very large tiger fossils were also discovered during the last interglacial period(Fig.A) and the LGM in region 2(These habitats, which are considered highly likely to be suitable for tigers, have also yielded large tiger fossils in many locations). However, due to the long-term interglacial and glacial replacement during the whole Pleistocene, tiger fossils in other Pleistocene sites in Japan may be relatively small (as Peter pointed out, island dwarfism may have occurred at specific times that Japan is not connected to the Asian continent).

The second one is about the explanation of the occipital.At first, when I posted this related context, I just wanted to explain some data, but personally, I also have my own views on this phenomenon.

*This image is copyright of its original author

Generally speaking, the occipital is directly related to the very important occlusal muscle - the temporalis muscle. In northern tigers (Amur tigers and Caspian tigers), the sagittal crest is also very developed, which indicates the need for strengthening their occlusal muscles. Amur tigers have the strongest sagittal crest and widest occipital. Relatively speaking, although the Caspian tiger is very developed, it is not as exaggerated as the Amur tiger. My viewpoint is that the size of SOB is the same as the level of development of the sagittal crest, which is also an evolutionary feature supporting the theory that Amur tigers need to gnaw on frozen meat in extremely cold regions.The same example can be seen in cave lions, where these Pleistocene cats can even be distributed within the Arctic Circle, and many of them also have very wide occipital.

This feature is not entirely related to body size, as the largest tiger in history, Panthera tigris soloensis, like Java tiger and Bali tiger, has relatively thin occipital, while the Sumatran tiger is believed to have been formed by natural hybridization between continental and island tigers, although this theory still requires more evidence

The above are some of my opinions. Everyone could share your idea~

return 80 · Yesterday, 04:02 PM

(Yesterday, 03:54 PM)return 80 Wrote:
(03-02-2025, 07:40 PM)return 80 Wrote:
The SOB and OH of tigers

The Supraoccipital breadth(SOB) relative to the Occipital height(OH) In previous studies, it was considered a significant distinguishing feature between different subspecies of tigers, and even now it has at least valuable population identification significance.

*This image is copyright of its original author

In tigers, the relative width of SOB can be clearly defined as gradually increasing from south to north on the Asian continent, which seems to be a functional adaptation caused by their corresponding ecological environment.

*This image is copyright of its original author

However, there does not seem to be much data on SOB in the literature, and it is generally not a major measurement value.

Its measurement method is"the smallest distance between notches of lateral margins of the occiput; the notch being situated approximately where sutura occipitoparietalis, sutura parietotemporalis and sutura occipitotemporalis meet"(Ji H. mazák 2008)

I have seen a good structural diagram(see blow, Narimane Chatar et al.2022) that can clearly distinguish these bone sutures. Please pay attention to the intersection of the occipital and parietal and the temporal in the diagram.

*This image is copyright of its original author

In the posterior view provided by Ji H. mazak, the specific location is the highest point on the dorsal side of the mastoid process And the Dorsal view can be seen in Figure B. Búzás and B. Farkas 1996.

*This image is copyright of its original author

In the publications of V. mazák and Ji H. mazák, it seems that I can only find specific data on island tigers and indochinese tigers (including Malayan tigers)

*This image is copyright of its original author

However, in his publication<Recent Advance in Tiger Phylogeny, In the Evolution and Geographical Variation >(Chinese version), he listed the scatter plot data of male SOB for all subspecies.

*This image is copyright of its original author

According to the scatter plot, we can see that the Amur tiger has a significantly widest SOB, both in terms of relative width and absolute width.Corresponding to the logarithmic axis of SOB, the SOB of some particularly wide male Amur tiger individuals may even reach around 90mm, almost 1.8 to 2 times that of some small Java and Bali tigers.

One of the male Sumatran tigers is very interesting, with a maximum recorded SOB of 83.4mm. Such a huge size makes it easy to find in scatter plots. From the graph, it can be seen that its SOB is almost as wide as the widest male Bengal tiger and comparable to many male Amur tiger individuals, which is very astonishing.
The two posts I previously posted only explained some phenomenon reports, but did not provide content explanations. Indeed, this is very necessary, so here I share some of my views

Although Hasegawa has reported multiple tiger fossils sites from Japan, unfortunately, these materials have not been systematically organized, so I can only provide some speculations on why Shiriyazaki's Late Pleistocene tigers were so large.

*This image is copyright of its original author

According to the ecological geographic model of tiger populations by Luo et al. 2024(https://doi.org/10.1038/s41559-023-02185-8), we can see that during the LGM (Last Glacial Maximum,Fig.B), Japan was connected to the Asian continent due to sea level decline, and at this time, Japan was also a high probability habitat suitable for tigers (red area).

Some of tigers may have migrated from China to Japan, and very large tiger fossils were also discovered during the last interglacial period(Fig.A) and the LGM in region 2(These habitats, which are considered highly likely to be suitable for tigers, have also yielded large tiger fossils in many locations). However, due to the long-term interglacial and glacial replacement during the whole Pleistocene, tiger fossils in other Pleistocene sites in Japan may be relatively small (as Peter pointed out, island dwarfism may have occurred at specific times that Japan is not connected to the Asian continent).

The second one is about the explanation of the occipital.At first, when I posted this related context, I just wanted to explain some data, but personally, I also have my own views on this phenomenon.

*This image is copyright of its original author

*This image is copyright of its original author

Generally speaking, the occipital is directly related to the very important occlusal muscle - the temporalis muscle. In northern tigers (Amur tigers and Caspian tigers), the sagittal crest is also very developed, which indicates the need for strengthening their occlusal muscles. Amur tigers have the strongest sagittal crest and widest occipital. Relatively speaking, although the Caspian tiger is very developed, it is not as exaggerated as the Amur tiger. My viewpoint is that the size of SOB is the same as the level of development of the sagittal crest, which is also an evolutionary feature supporting the theory that Amur tigers need to gnaw on frozen meat in extremely cold regions.The same example can be seen in cave lions, where these Pleistocene cats can even be distributed within the Arctic Circle, and many of them also have very wide occipital.

This feature is not entirely related to body size, as the largest tiger in history, Panthera tigris soloensis, like Java tiger and Bali tiger, has relatively thin occipital, while the Sumatran tiger is believed to have been formed by natural hybridization between continental and island tigers, although this theory still requires more evidence

The above are some of my opinions. Everyone could share your idea~

Additionally, this is a slight supplement to my explanation

Tiger fossils from the last interglacial period in region 2

Although I still have more information and data on tiger fossils, I may discuss them in more detail later.In the Qingjiang(Chinkiang,see<What is Tiger>, But I must clarify that the tiger fossils in this area come from different eras, and the author Andrew C. Kitchener simply listed them as Middle Pleistocene tigers) River Basin between the last intergalactic period in Region 2 (90000-120000 years ago,silver carp Hill).

There are fossils from at least 3 different individuals, almost all of which are the size of male Amur tigers - super large male Amur tigers, similar to the giant Japanese tiger fossils we previously discussed.

These materials include a tiger maxilla with a length of 113mm for C-P4 and 40mm for P4 (almost the same size as the maxilla of the largest Amur tiger skull)

A mandibular anterior segment larger than any modern tiger's mandible record,Its related measurements are much larger than the mandible of a male Amur tiger(ルー)with a skull length of 380mm

A 425mm femur(The size of a large male Amur tiger)

A 340mm tibia(The usual size of male Amur tigers)

Additionally, The interesting thing is that in the research I previously cited（ https://doi.org/10.1038/s41559-023-02185-8 ）

The genetic similarity between their ancient Russian tiger samples and today's Amur tiger is not high, while an ancient tiger from nearly 2000 years ago has a relatively high genetic similarity with the Amur tiger. This suggests that today's Amur tigers may actually be very young tiger populations, and they have not been separated from other tiger populations for too long.

The other research also proving that a tiger sample(Da an Tiger) from northern China during the Late Pleistocene(more than 40000 years ago) is from an extinct branch of tigers that had been separated from modern tigers for hundreds of thousands of years(see
https://doi.org/10.1098/rspb.2022.0617)

return 80 · Yesterday, 04:37 PM

Share a skull photo

*This image is copyright of its original author

This is the only photo of the skull of a male Caspian tiger whose origin is China that I found on the Chinese Internet.

It may have been taken by Ji H. Mazák and catalog number is ZIN 4046(housed in Zoological Institute of the Russian Academy of Sciences). According to relevant archives, it should have come from Yili(Kuldzha), Xinjiang Province, northwest China in 1888

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