(01-06-2019, 05:49 AM)Wolverine Wrote:

(01-05-2019, 09:07 PM)Shadow Wrote:

(01-04-2019, 08:47 PM)peter Wrote:

(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:

"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."

https://www.lakeforest.edu/live/news/5515-impact-of-wolf-reintroduction-on-bison-and-grizzly?preview=1

Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.

AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
 
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.

I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.

TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013  - DISPLACEMENT

A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.

In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.      

In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger. 

All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.

TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS

In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.

Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.

Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.   

TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS 

Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species).  In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.

According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:

*This image is copyright of its original author

Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.

Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW). 

My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:  

*This image is copyright of its original author

 

CONCLUSIONS

The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.

Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.  

01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.

02 - Most bears are not hunted in winter, as many assume, but in summer. 

03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.  

04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.  

05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.

06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).

07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.

08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.

Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.

Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.  

09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013. 

10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.

Here is something about 07: "07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013."

Here is another study (looks like to be overall of whole population) about mortality of Amur tigers 1985-1996. This study is partially overlapping with Sikhote-Alin report what comes to timeline. I have to say, that human caused death numbers were shocking in a way to realize, when we know how small number of tigers there is... But this report isn´t in contradiction with that, what Peter wrote. This report is from all population, not only from Sichote-Alin Nature Reserve. I haven´t seen more recent report yet about all Amur tiger population.

Very interesting Shadow. Where did you dig out this paper? If I am not wrong Its written that for the period 1985-1996 in entire RFE totaly 7 tigers have been killed by bears and 4 tigers have been killed by wild boars. But this data is for entire Russian Far East while the paper posted by Peter was only for Sihote Alin state reserve which is unsignificant percentage of Ussuriland teritory. So, there is no any contradiction.

(01-06-2019, 10:10 AM)Greatearth Wrote:

(01-06-2019, 09:49 AM)Wolverine Wrote: I remember that as a child red in Red book of Soviet Union (from 1980's or 1970's) that even in pre-industrial age, before human colonization of RFE Amur tiger's population was assessed at around 700-900, there were never more than 700-900 wild tigers in what is today Russian Ussuriland. Amur tigers have never been numerous. 

That's way we have to understand that there is only one true Kingdom of Tiger in this planet and this is INDIA. Tropical ecosystems are much more fertile than northern ecosystems, density of tropical tigers is 15-20 larger than dencity of Siberian tigers. In one small Kaziranga NP on territory of 430 sq.km. live 90 tigers while in gigantic Bikin NP with territory of 11 600 sq. km.  live only 40-50 tigers. 
Every square feet of Indian jungle is teeming with life, every square feet of Indian jungle is a diamond! @Rishi

Really? So Siberian tigers were always small numbers in Russia? 700-900 seems to be too small. Wouldn't be just in Ussuriland? How about other states in Russia? Moreover, places like Manchuria? I think Manchuria was once hold the highest populations of the Siberian tigers. Plus, many people also hunts their food like deer a lot in 20th century. Korea had a high density of tigers compared to its size.

I was always wondered that why tiger population was high in India even though they were exceptionally hunted just like in other Asia. It maybe different reasons. I don't know places like other South East Asia (India is also much larger than other SE Asia country). As for biodiversity, Indochina has much higher biodiversity than India. About population of large mammals seem to be different. However, I am curious why prey density in South East Asia is smaller than India.

China once had the Siberian tiger, Caspian tiger, South China tiger, Indochinese tiger, and Bengal tiger. China was also experienced different ecosystems throughout the times due to human impacts throughout each dynasties.
I am not sure how many tigers were in mainland China 100~150 years ago. I believe that Kingdom of Tiger was for both China and India, I would put more hand on China though. Difference is that chinese lost that title by themselves.

(01-07-2019, 08:23 PM)Shadow Wrote: When looking at bears in Ussuri area, in 2015 they showed for sure, that there they are. Lack of food makes people and animals behave in unnatural ways.

https://www.theguardian.com/world/2015/sep/04/russian-town-besieged-by-hungry-bears

(01-07-2019, 08:44 PM)epaiva Wrote:

(01-07-2019, 08:23 PM)Shadow Wrote: When looking at bears in Ussuri area, in 2015 they showed for sure, that there they are. Lack of food makes people and animals behave in unnatural ways.

https://www.theguardian.com/world/2015/sep/04/russian-town-besieged-by-hungry-bears

@Shadow
Thanks for information and videos, the Bear they killed looked  big and powerful

(01-07-2019, 08:47 PM)brotherbear Wrote: I had the idea that tigers originated in a cold climate in China. Tigers in the tropics sometimes appear to be uncomfortably hot and thus spending time soaking in ponds and rivers. Have I been wrong in this assumption?

(12-25-2018, 07:22 AM)Wolverine Wrote: DHOLE (CUON ALPINUS) AS PART OF AMUR TIGER'S FAUNA COMPLEX

Dhole or Indian wild dog is probably the only mammal specie extinct from the forests of Russian Ussuriland. Ussuri dhole was the largest of all subspecies with long winter hair and once inhabited the southern parts of Primorskij region. Its start desapiaring during 20th century for not very clear reasons and was last spotted in 50's. 

*This image is copyright of its original author

Probably the only Usuri dhole trophy survived:

*This image is copyright of its original author

*This image is copyright of its original author

DECLINE OF THE DHOLE AS RESULT OF THE DECLINE OF AMUR TIGER AND RISE OF THE GREY WOLF IN RFE. STRANGE TRYANGLE.

Dholes are canids known to be bold towards big cats (tigers and leopards) and very shy and defensive towards other canids (especially grey wolves). In same time Amur tiger is notorious for his hostility and untolerance towards the grey wolves sometimes bordering a genocidal behavior. In places with high density of Amur tigers wolves almost completely disappear because tiger probably consider them as a prime competitor hunting same prey. 
During 19th century when tigers were plenty travelers in Russian Ussuriland almost didn't find any wolves. But when during 20th century Amur tigers were decapitated for first time wolves start appearing in large quantities in Sihote Alin mountains literaly invading it. Exactly in this period start decline and extinction of the dholes in Ussuriland. Is this coincidence? Probably not. Since dholes have never been persistently hunted by people and they inhabited mainly remote areas unsuitable for agriculture some Russian scientists sujest one of the main reasons for the decline of the Indian wild dogs in RFE was the rise of the grey wolf in 20th century as result of the decline of Amur tiger. Northern wolves as larger and more powerfull canids start pressing dholes. Tiger and dhole are mutualy tolerable species and they wonderfully coexist in same ecosystem. So, Amur tigers was a "guardian" of the Indian wild dogs and when it disappeared swiftly deseapeared the dholes. The most interesting is that dholes themselves are much bolder, sometimes said even aggressive toward tigers than wolves.

Probably one day Indian wild dog has to be re-introduced in Sihote Alin mountains, instead of exinct Ussuri subspecie could be used long haired dholes from Tibet (China). @peter what do you think? Once upon a time Russian Far East was second in the planet after India in terms of variety of big predators: tiger, leopard, brown bear, Asiatic black bear, grey wolf, dhole, lynx and wolverine.

(01-14-2019, 08:13 AM)peter Wrote: I didn't read anything about grey wolves or dholes Arseniev's book ('Dersu the Trapper'), but Velter's book has a bit more on wolves and dholes.