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

[Shadow]

(12-16-2018, 04:00 PM)peter Wrote:

(12-16-2018, 10:21 AM)Wolverine Wrote:

(12-15-2018, 11:05 AM)peter Wrote:

(12-14-2018, 06:43 PM)Shadow Wrote:

(12-13-2018, 10:49 PM)peter Wrote: KUCHERENKO

I saw the famous Kucherenko-table in an article written for hunters. American trophy hunters, to be precise. Based on what I read, I'd say it was written to encourage them to visit the Russian Far East. 

Hunters like size. The bigger, the better. For this reason, Kucherenko could have selected large individuals only. Recent research says adult males, like he said, really average 590-600 pounds in the Russian Far East, but the range most probably isn't as limited as in Kucherenko's table (260-320 kg. or 565-722 pounds).

The table below, first posted by Warsaw in AVA, about the size of brown bears in the northeastern part of Russia could be more accurate. The sample is larger and the range is much more outspoken:

*This image is copyright of its original author

 

I know the bears in the table do not quite belong to Ursus arctos lasiotus, but it has adult males only and in size they more or less compare to their relatives in the Russian Far East. Individual variation, as you can see, is very pronounced. Whereas some of them, at least weightwise, are within the predatory reach of male Amur tigers, the great majority is not. A few are very large. 

A good table should have distinctions between age classes, especially in large and long-lived mammals like brown bears. The table Guate today posted about averages in Kodiak brown bears clearly shows the outspoken differences between age classes.

There are different ways to get to age classes. In the thread about male tigers and male brown bears in old AVA, I posted about a paper written by B.P. Zavatsky (1976). He studied skulls and teeth to get to age-based distinctions in brown bears: 

https://www.bearbiology.org/wp-content/uploads/2017/10/Zavatsky_Vol_3.pdf

There's much more where this came from (the internet), including recent articles about skulls of brown bears in Bulgaria and Iran. 

Based on everything I read, I'd say that one has to distinguish between young adults (5-8), adults (9-12), mature adults (13-18) and old adults (> 18) in large brown bear subspecies like Kodiak bears. At the level of averages, the difference between the age groups is considerable. Like tigers, brown bears seem to keep on growing nearly all their life. Skulls of old bears nearly always are larger and heavier than those of younger individuals. 

Male Amur tigers involved in brown bears occasionally attack adolescent males, but I never read anything about tigers preying on young adult males, let alone adults and older males. This although young adult males are not much bigger than mature females. 

According to Kerley, male Amur tigers hunt female brown bears " ... up to the largest and healthiest (individuals) ... " (from her mail to Junglesprout in September 2011). Her observation was confirmed by others. The question is why they do not hunt young adult male brown bears similar in size and weight (150-200 kg. or 330-441 pounds). My guess is it could be a result of a combination of strength and disposition. In the Russian Far East, brown bears are known for their disposition. Pikunov said they're more dangerous than Amur tigers.     

As to posts about bears in this thread. I don't mind good info about bears, provided it's related to the Russian Far East. The reason is Amur tigers, brown bears and Himalayan black bears live in close proximity in southeastern Russia. Info about the way they interact is of interest, that is.

There was this part of your posting which was in a way especially interesting for me: 

"According to Kerley, male Amur tigers hunt female brown bears " ... up to the largest and healthiest (individuals) ... " (from her mail to Junglesprout in September 2011). Her observation was confirmed by others. The question is why they do not hunt young adult male brown bears similar in size and weight (150-200 kg. or 330-441 pounds). My guess is it could be a result of a combination of strength and disposition. In the Russian Far East, brown bears are known for their disposition. Pikunov said they're more dangerous than Amur tigers."

Of course male bears can be aggressive in certain situations even though usually bears are towards humans pretty harmless.

Anyway it is interesting if/when bears in Russian far east are known for their disposition. Does this concern all brown bears there or is this the matter among Ussuri brown bears living at same areas as tigers. Just thinking, that have Ussuri brown bears evolved to be more aggressive because have to deal with tigers. It sounds sensible, because that could be a way to minimize a risk for a fight with tiger. Of course if that concerns all brown bears from Ussuri area to Kamchatka peninsula, then looks to be some other reason, maybe they are just all "mental" :)

It just is interesting to know if there are differences between brown bears living in "tiger areas" and other brown bears. Olga.boshoi also had interesting posting about brown bears and tigers recently in Bear and Big Cat interactions in the wild thread.. 

So now what I am thinking is, that is there partial expelling of bears at areas where tigers are. And this issue about male bear disposition at same area, could these things connect in some way and be pieces of puzzle giving more information about interactions between Ussuri brown bears and Amur tigers. Females and cubs going to outer regions of areas with higher tiger density and then leaving there less bears, but then again are those bears inside tiger areas then mostly more fierce male bears with attitude (alongside big size) keeping them safe from tiger attacks?

One thing about bears which should be also remembered when thinking their movements. During breeding time male brown bears are very aggressive (from May to July, mostly on June). At that time female bears with cubs try usually to avoid them and leave areas where male bears. Reason is, that male brown bears can kill cubs in hope to make female bear again in heat. If male bear manages to kill cubs of a female bear, that female bear is soon ready to breed. Otherwise females aren´t eager to do that until former cubs are independent. So at that time of year there is movement among bears. Especially at June tigers are not only problem for female bears and cubs. There is even research indicating, that female bears with cubs move closer to human habitats during breeding time and avoiding in that way male bears which even at that time avoid humans. Quite interesting when thinking how animals can adapt their behavior.

THE SIBERIAN TIGER PROJECT (STP)

The Siberian Tiger Project (STP), a joint effort of Russian and American biologists to get to more knowledge about Amur tigers, started in 1992. It has been a very productive effort in all respects: 

1 - myths have been replaced by knowledge;
2 - there is much more interest in conservation in general; 
3 - the number of tigers has grown considerably, and, last but not least, 
4 - people seem prepared to make room for them and all their neighbours. 

If Pikunov's proposal to create two more reserves will be adopted and the new reserve in China is added, chances are the next generation also will be able to visit the only region on this planet where tigers and brown bears co-exist. A region unsurpassed for beauty as well. The effort in the Russian Far East is in many ways examplary. One can only hope the STP (and the Amur Tiger Programme) will continue for many more years. 

TIGERS AND BEARS BEFORE THE STP STARTED
 
Before the STP started, the situation on tigers and bears was unclear. Based on everything I read published before 1992, I'd say that most thought that tigers only hunted bears in years when red deer and wild boars had migrated to greener pastures. Back then, it was also assumed they hunted most bears in winter. In spring, summer and autumn, tigers, when they hunted bears at all, preferred cubs.  

This assumption was based on a number of incidents in which tigers had been killed by brown bears. Although biologists agreed that an experienced tiger could surprise a largish bear, most assumed that brown bears were too dangerous to hunt. 

TIGERS AND BEARS IN THE FIRST TWO DECADES OF THE STP - ASSUMPTIONS CONFIRMED

The documents published in the first two decades of the STP more or less confirm most assumptions discussed above. They also said that wild Amur tigers were quite a bit smaller than the alleged giants shot a century ago. Although the sample used to get to conclusions was small and polluted by 'problem tigers' and young adults, some biologists, like some of their collegues in India, used the results to underline their opinion on old hunting records in general. They concluded that most of the old records were a result of stretched skins, 11-inch tapes, inadequate scales, preferenced Maharajahs and myths. 

Brown bears, on the other hand, were as large as ever. There was also no question that they were able to displace tigers almost at will, they thought. Agreed, some male tigers had killed a few adult female brown bears, but they often had a significant advantage and their victory had come at a cost. One male had been quite severely wounded by the female he had killed after a 20-minute fight.

THE INITIAL RESULTS - HEATED DEBATES

I'm not saying they reminded me of Clyde Beatty, but most statements discussed in the previous paragraph had to be, ehh, 'refined' later. That was after they had resulted in heated debates between those interested in tigers and bears. 

Unexpectedly, quite a few of these debates proved to be productive in that posters more or less concluded the tiger and bear situation could be a bit more complicated than some biologists assumed. They were quite close.

TIGERS AND BEARS IN THE LAST DECADE OF THE STP - MYTHS DEBUNKED

In the last years, the pendulum shifted once again. Based on the documents published between, say, 2009-2017, it seems safe to conclude that

1) tigers hunt bears, including brown bears, more often than was assumed.
2) So much so, that they are as important as red deer and wild boars in some regions and seasons.
3) Tigers do not hunt bears in winter, but in spring, summer and autumn. 
4) Although male tigers in particular hunt bears, tigresses have been active in that department as well. 
5) Tigers seem to prefer quite large bears " ... up to the size of the healtiest and largest female ... " (L. Kerley, 2011).
6) The pressure on female brown bears is so high, that they left districts inhabited by male tigers interested in bears.
7) Recent research confirms that brown bears displace tigresses, but it doesn't happen as often as many assumed.
8) Male tigers are not displaced by male brown bears. At least, not in the reserve monitored by biologists in the period 1992-2013.

MYTHS AND RESEARCH - A FEW CONCLUSIONS

As some stated some years ago, research nearly always debunks myths. Not quite in the direction they initially thought, but debunked they were. The conclusion is that research is the best way to get to knowledge. On the present situation. 

Another conclusion is that it takes time to get to correct conclusions. Things often are a bit different than many initially assume. Time, therefore, is a factor to consider.

Finally, one has to assume that things can change over time. Mammals can, and often will, adapt their behavior over time. Same for tigers and bears in the RFE. 

MALE TIGERS AND MALE BROWN BEARS - PROPOSAL FOR A DEBATE

One conclusion that hasn't been debunked is that tigers do not hunt adult male brown bears. The only male brown bear partly consumed by a male tiger in the reserve monitored in the period 1992-2013 had been killed by another male brown bear.

It's not too difficult to find a good reason: male brown bears are as large as male tigers or larger (a); they are very agile for their size (b) and they often have a significant weight advantage ©. At roughly similar size, they are more robust than male tigers. As a result, they are very difficult to kill (d).

One wonders why that advantage isn't used to displace male tigers. We also never heard anything about fights between adult males. What are we missing?

The only way to get to an answer is to discuss male tigers and male brown bears once again. I'll start it with two posts I printed about ten years ago. Their were posted by 'Big Bonns', a bear poster from old AVA. One has info from a trainer he interviewed. In the other, Dmitry Pikunov, an authority on tigers and brown bears in the Russian Far East, features.

My proposal is to stay away from opinions if possible and to break both posts down. If we do it step by step, chances are we will get to a sound conclusion.

Before I start, however, I want to do another post on Pikunov's article 'Population and Habitat of the Amur Tiger in the Russian Far East'. His proposals need to be discussed first, as they are of vital importance for tigers.

For sure brown bears displace mainly tigresses, but displacing of male tiger by huge brown bear is not impossible. In the interview published February 2017 in the Russian hunting magazine "Ohotniki.ru" below an old hunter Viktor Belozerov told to the journalist a story witnessed many years ago when he was still a young hunter (probably in 1970's) when a huge brown bear was persistently displacing a male Amur tiger:

https://www.ohotniki.ru/hunting/article/...vanie.html

*This image is copyright of its original author

"In November that year I witnessed following event. Around the river started coming a brown bears, they didn't go to hibernation. One of them found a way how to eat tasty pork without making any hunting efforts. He got a tiger's traces. And so the tiger kills a boar than the bear comes, chase away the stripe and appropriate the carcass. And the traces of that bear were gigantic. Me and my friend both have choose size No 45 and we together placing our feet on the bear trace couldn't cover all the trace. Tiger without any fight gave up and go away.


After that I was roaming in the hunting grounds and again and again observed the same behavior. The bear was following persistently. Tiger kills than bear appropriates. And that story continued for long period of time. And than both predators disappeared. Or the tiger got bored by such a hooligan behavior and he changed his hunting grounds or the bear got enough fat for the winter and went hibernating.

- How come the bear dared to confront tiger? (asks journalist)

- Brown bears in our lands are similar in size and power with bears from Kamchatka. In good year when there are a lot of food in the forest bears from Primorskij region could reach up to 600-700 kg body mass. But bears and tigers avoid fights."

The story starts 12 rows beneath the bear's photo. In Russian for "tiger" and "tigress" exist 2 different words as in English, and in same way sometimes tigers from both sexes could be called with general word "tiger" but nevertheless in this case I'm 80% sure that is described a male tiger displaced by huge  brown bear.

*This image is copyright of its original author

This is what authorities like Baikov, Sysoev, Krechmar and Pikunov said as well. Some brown bears (see, for instance, the table with measurements and weights of adult male brown bears in northeastern Siberia) are so large, they should be able to displace any tiger.

I was a bit surprised to read that no clear evidence of male brown bears displacing male tigers was found in the Sichote-Alin reserve in the period 1992-2013. This although male brown bears (referring to the table posted by Guate) really average very close to 600 pounds.

The question is why large male brown bears didn't use their advantage in weight to displace male tigers.      

Good find.

I don´t see any reason to doubt this article with given information, that it was an exceptionally big bear. Even though we seek proven facts, same time it has to be remembered, that it is impossible to get those for everything, especially about events, which are not the most common. There is no doubt, that there are some very big bears also in Ussuri area time to time. But, then again all known information, what can be considered to be reliable or at least probable indicates, that biggest bears most commonly can be found from Kamchatka, Alaskan coastal areas and from Kodiak islands. So yes, there are big ones in Ussuri area too, but not all the time and everywhere.

Then again male tiger is really the toughest opponent a bear can confront. To do that there most probably have to be a quite confident (or hungry) bear used to dominate even other male bears. So when we need a combination of big size and certain kind of character in one bear, maybe this isn´t something to be surprised, that hard to find many cases which would have been witnessed or documented. It is after all quite different thing to be a 200-300 kg bear and live there side by side with tigers, than trying to challenge them all the time. 

This article for me was pretty much one example how hungry dominant predator acts. It takes food from anywhere, when situation demands it. When snow is on the ground, there is nothing else to eat but meat. Then again at that time of year bear is not in fastest condition, so what is left. Carcasses. Is there a tiger or not is at that point not the most important thing for a bear, it needs food and goes to take it. And big bear is able to do that. Then again tiger usually has been able to eat at least something before the bear arrives there. It also is in hunting condition, so if tiger is as intelligent as it is said, it has to have understanding, that it can go and hunt something else instead fighting a beast maybe twice as big as itself or even bigger, which shows clearly, that now it is there to fight if that is what it takes. 

Speculation partially of course, but cases in wildlife show, that smaller predator gives up in situations, where bluff doesn´t work anymore against bigger one. Reply