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

Finland Shadow Offline
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( This post was last modified: 11-02-2018, 10:06 PM by Shadow )

(11-02-2018, 06:11 AM)peter Wrote: INTERSPECIFIC RELATIONSHIPS BETWEEN THE AMUR TIGER (P.t. altaica) AND THE BROWN (U.arctos) AND ASIATIC BLACK BEARS (U. thibetanus) - III

B - background information

07 - Research was done in the Sichote-Alin Nature Reserve and the surrounding area, including the Ussuri river basin. This is the location of the Sichote-Alin Nature Reserve:


*This image is copyright of its original author
  
 
08 - We now briefly jump to an article published in 2015. In that one, tigers and bears also featured. I posted 6 scans. The first aim of the scans is to show you that the Southwest Primorskii Krai in the article published in 2015 is the Sichote-Alin Nature Reserve in the article published in December 2017 (third scan). The second aim is is to show you that tigers in the Sichote-Alin Nature Reserve (the Southwest Primorskii Krai in the article published in 2015), compared to tigers in the Lazovsky State Nature Zapovednik (LZ) and in the Sichote-Alin State Biosphere Zapovednik (SABZ), were quite modest in the bear hunting department (fifth scan):      


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


09 - Another reason to jump to the article published in 2015 is to show that those interested in the importance of bears for tigers have to distinguish between kills, scats and biomass. 

The authors of the article published in 2017 say " ... Bears are an important part of tigers' diet, representing 2,2% of all kills found ... " (abstract). 

Readers not informed on tigers and bears might wonder about the remark on 'bears as an important part on tigers' diet' and the percentage (2,2% only), seemingly contradicting the first part of the sentence. The confusion no doubt grows when they read that " ... Bear remains were found in 8,4% of examined tiger scats ... " (abstract).

A few pages later, the authors add that " ... According to Kucerenko (1977), the Amur tiger produces on average three bears of two species per year and seizes around 3-4% of the populations of the autumn bears. He noted it is found that the weight fraction of bears in the composition of feed ... reaches 12% and is higher than their frequency occurence, since the average bear is superior in weight to other predator prey ... " (Discussion, fourth paragraph).

The last remark, however, contradicts  a statement of Khramtsov, also in the article published in 2017: " ... Often, the victims of the tiger are young bears (Khramtsov, 1993) ... " (Discussion, second paragraph on page 7).

In order to get things really complicated, the authors add that " ... Some tigers appear to be more likely than others bear, but it can only be adult males who are able to join in the confrontation with the bears. From the literature, only two cases are known when brown bears were extracted by female tigers (Kaplanov, 1948, Bromley, 1965) ... " (Discussion, first paragraph).

This, of course, is even without the remark on sudden (local) changes: " ... As can be seen from other studies (Table 1), the presence of bears in the tigers' diet varies widely depending on local conditions and applicable methods of appreciation and can reach in some cases 31,2% (Tkachenko, 2012). Even in one (region?), the share of bears in the tigers' diet from year to year can significantly change (Poddubnaya & Kovalev, 1993, Tkachenko, 2012) ... " (Discussion, third paragraph).

Did I, by the way, tell you about the effect of 'pseudoreplicates' in the article published in 2015? If not, read the scans I posted. Interesting.  

To conclude.

Things are quite complicated in tigers and bears in the Russian Far East. Based on the article published in 2017, however, we can get to three small results:  

a - Using the article published in 2017 only, it's quite safe to conclude that tigers hunting bears in the Sichote-Alin Nature Reserve and the Bikin river basin do not select cubs and immature animals, but, regarding brown bears, adult females or, regarding Himalayan black bears, adults of both sexes. This runs counter to " ... previous assertions that the risk of injury was too high for tigers to regurlarly predate bears (Miquelle et al. 2010) ... " (Kerley et al. 2015, see the third scan).

b - The article, again, confirms that adult male brown bears are not hunted by Amur tigers. Not in the period 1992-2013 in the Sichote-Alin Nature Reserve, that is.

c - The article also confirms that adult male brown bears do not displace adult male tigers. Not in the period 1992-2013 in the Sichote-Alin Nature Reserve, that is.   

10 - To conclude this post (part III), I added a few photographs I found on the internet.

Sichote-Alin Nature Reserve - three photographs taken by John Goodrich:


*This image is copyright of its original author



*This image is copyright of its original author



*This image is copyright of its original author
  

Sichote-Alin Nature Reserve - House of employees (Y. Smityuk):


*This image is copyright of its original author


Sichote-Alin Nature Reserve - male tiger (National Geographic):


*This image is copyright of its original author


Sichote-Alin Nature Reserve - male tiger:


*This image is copyright of its original author


Sichote-Alin Nature Reserve - male tiger (Jonathan Slaght):


*This image is copyright of its original author


Sichote-Alin Nature reserve - brown bear:


*This image is copyright of its original author


Lazovsky Zavopednik - Himalayan black bear (Vladimir Medvedev):


*This image is copyright of its original author


Lazovsky Zapovednik - tigress:


*This image is copyright of its original author

Some things can look like confusing, but then again when looking closer, not so confusing after all. Just not enough information or then report is made from another point of view than many readers have.

I put this part here to explain what I mean:

"A few pages later, the authors add that " ... According to Kucerenko (1977), the Amur tiger produces on average three bears of two species per year and seizes around 3-4% of the populations of the autumn bears. He noted it is found that the weight fraction of bears in the composition of feed ... reaches 12% and is higher than their frequency occurence, since the average bear is superior in weight to other predator prey ... " (Discussion, fourth paragraph).


The last remark, however, contradicts  a statement of Khramtsov, also in the article published in 2017: " ... Often, the victims of the tiger are young bears (Khramtsov, 1993) ... " (Discussion, second paragraph on page 7)."

First here are two different researches. Then even young bear can be relatively big compared to other prey of tigers. If Khramtsov meant by young bears for instance up to 4-6 years, bear is young and far from full sized, but already reasonable sized and lot to eat if killed. Brown bear especially. It would be nice to know if Khramtsov was talking about brown bears or both, black bears and brown bears. Still it is logical, that tigers kill often younger ones, which are less experienced and easier to surprise even though when target is smaller black bear, tigers for sure can attack any individual when opportunity comes. It is hard to say if there is any real contradiction or just observations from so different kind of points of views, that Khramtsov didn´t see it so important to write so detailed information about things he thought to be less important.

When reading older and new information about bears and amur tigers, I think, that there isn´t any fundamental contradiction. Some hunters telling stories, probably 50-70% true. I mean hunters have this strange habit to kill always very big animals if there is no possibility to officially measure killed animal. In photos we see giants, especially when smallest person in group is in the photo with "gigantic animal" :Grin Naturally these beasts have just killed some other monster and so hunter is in "reality" a hero saving half continent taking out that beast :)

Then we have more reliable woodsmen and researchers, who have good information and sometimes even measurements looking to be quite reliable. And then researches about different things giving parts of information from here and there.  Only lately there has been some real research about relationship between Amur tigers and bears. 

Still the big picture in all information is quite same actually. Black bears are easier prey for tigers and in that species no individual is "untouchable". With brown bears tigers are more cautious and attack only to "softer targets". And it is just logical. When hunting it matters how dangerous the prey is to hunt. What can confuse many readers when looking quickly some document is, that often there is written just "bears", not separated black and brown bears. Tigers do separate those animals though, because brown bear is way more dangerous for a tiger than a black bear. It is nice, that now also researchers have studied a little bit of this subject, because after all it is interesting for many, even though pretty meaningless when thinking conservation of these animals.
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Messages In This Thread
RE: ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris) - Shadow - 11-02-2018, 03:52 PM
Demythologizing T16 - tigerluver - 04-12-2020, 11:44 AM
Tiger Data Bank - Apollo - 07-28-2014, 09:54 PM
RE: Tiger Data Bank - Apollo - 07-28-2014, 10:02 PM
RE: Tiger Data Bank - Apollo - 07-29-2014, 12:56 AM
RE: Tiger Data Bank - peter - 07-29-2014, 07:05 AM
Tiger recycling bin - Roflcopters - 09-04-2014, 01:36 AM
RE: Tiger recycling bin - Pckts - 09-04-2014, 02:22 AM
RE: Tiger recycling bin - Roflcopters - 09-05-2014, 01:01 AM
RE: Tiger Data Bank - Apollo - 11-15-2014, 10:07 PM
RE: Tiger Data Bank - Apollo - 11-15-2014, 10:57 PM
RE: Tiger Data Bank - Apollo - 11-15-2014, 11:33 PM
RE: Tiger Data Bank - Apollo - 02-19-2015, 11:25 PM
RE: Tiger Data Bank - GuateGojira - 02-23-2015, 11:36 AM
Status of tigers in India - Shardul - 12-20-2015, 03:23 PM
RE: Tiger Directory - Diamir2 - 10-03-2016, 04:27 AM
RE: Tiger Directory - peter - 10-03-2016, 06:22 AM
Genetics of all tiger subspecies - parvez - 07-15-2017, 01:08 PM
RE: Tiger Predation - peter - 11-11-2017, 08:08 AM
RE: Man-eaters - Wolverine - 12-03-2017, 11:30 AM
RE: Man-eaters - peter - 12-04-2017, 09:44 AM
RE: Tigers of Central India - Wolverine - 04-13-2018, 01:17 AM
RE: Tigers of Central India - qstxyz - 04-13-2018, 08:34 PM
RE: Size comparisons - peter - 07-16-2019, 05:28 AM
RE: Amur Tigers - peter - 05-20-2021, 07:13 AM
RE: Amur Tigers - Nyers - 05-21-2021, 08:02 PM
RE: Amur Tigers - peter - 05-22-2021, 08:09 AM
RE: Amur Tigers - GuateGojira - 04-06-2022, 12:59 AM
RE: Amur Tigers - tigerluver - 04-06-2022, 01:08 AM
RE: Amur Tigers - tigerluver - 04-06-2022, 09:08 AM
RE: Amur Tigers - tigerluver - 04-06-2022, 11:30 PM
RE: Amur Tigers - peter - 04-08-2022, 07:27 AM



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