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

United States Pckts Offline
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(09-24-2020, 04:08 AM)Shadow Wrote:
(09-24-2020, 03:41 AM)Pckts Wrote:
(09-24-2020, 02:28 AM)Shadow Wrote:
(09-24-2020, 02:02 AM)Pckts Wrote:
(09-24-2020, 01:25 AM)Shadow Wrote:
(09-22-2020, 04:59 AM)Pckts Wrote: Naren Malik talking about Kanha *Mukki Zone Tigers* and the Tiger fights he's seen, Pugmark Differences, etc.


Funny enough, all Tiger fights he's seen has involved Umarpani male. 




Pugmarks "10 month old Tiger cubs are equal to Leopard Pugmarks"




Driver talking about when Yuvraj killed a Bison.
"He jumped on him, injuring his hind legs and incapacitating him. The Gaur herd came and he charged at them to run them off then went back to attacking the Bison."




The driver is the perfect example of who the true experts are, no offense to anyone who studies these animals, they contribute immensely to the conservation of big cats but it's these guys who know everything there is to know. They are the ones that drive every day with these cats and it would truly be a treasure trove if they all got together and started documenting their stories.

Then we have zoologists, like Joseph Vattakaven and these other two men here, who have spent a lot of time on the field making first hand observations. Like 4 years of time spent (Vattakaven) to study  tigers hunting success rates mentioned on the video. From 2:40-3:40. 1/25 stalks lead to success, means 4 % success rate. I think, that there are no-one with better knowledge than he has concerning it, even though these safari guides see a lot.





Also people like Karanth, Vattakaven, Schaller, Sankhala and many other zoologists have spent days and nights and long periods of times in the forests to get first hand experience, not just sitting behind the desk in the office. 

For sure these guides see a lot, but I still think, that experts are experts for a reason. They know without a doubt many stories from guides too, but they also know very well themselves too, how things are in reality. While safari guides can put some extra to some stories to entertain visitors, people like Karanth and other experts have to be more down to earth.

Things are seldom black/white, but there is are reasons why some people are considered as experts and are widely respected for their knowledge and experiences.

100% but at the end of the day after they finish their research, they leave. These guides don't they continue to work there for years and years. They are locals who lived there and any research done cannot be done without the help of these drivers/locals.
In E. Africa, your guide is going to be tribesman from one of the 4 major tribes most likely, they are going to not only have years of experience tracking these animals but their ancestors will have years of experience living side by side with these animals, the same goes for India. 
Next is the fact that these researchers like Joe, study many animals and since they have the resources to do so, they divide their time between places, for most of the guides they don't get that luxury, the are forced to stay in one place and again that leads to more experience. 
These researchers may perform studies for years on end and learn a ton but they do so with the help of these guides who were there before them and will be there after them.


"Experts"

The term "expert" is vague, what exactly makes an expert?
Are you saying schooling is what makes an expert? 
In that regards, these guides cannot hold a candle.
Or, are we talking about experience?
In that regard, no zoologist or biologist can compete.

I gave an example with Vattakaven. No-one can convince me, that some safari guides would know better tigers hunting success rates than him. There are many other things which zoologists study with time and fully aware of stories from locals and guides etc. These zoologists also without any doubt notice if there are contradictions or exaggerations, like there are time to time. 

I posted my posting, because it´s not that simple that people should believe too blindly what guides tell. They know a lot, but there are many things in which they can make only guesses like others, while people like Vattakaven can say, that they know because they used a lot of time and effort to learn.

I pointed out another point of view. This is how I see this and I trust more to information from zoologists. Naturally other people decide themselves which sources they see most reliable. But many zoologists are really determined and spend a lot of time to learn how things really are.
And how exactly would he come across a Tigers hunting success rate?
Then what does it matter the success rate in which a single Tiger hunts in for a specific period of time?

For one, he'd have to study with the guides as they would be the ones driving him, tracking the tigers and telling him which tigers are which. 
The fact that he specifically studies the success rate means little to the driver as that isn't their goal, their goal is tracking the Tiger. So when it comes to knowing real facts about the animal like: It's sex, age, lineage, preferred territory, prey preference during which time of year, how they smell, when and where a kill has been made, what the seasons contribute to the tigers behaviors, how terrain effects the animal etc. It's the tracker that would have the researcher outclassed.

I'm not sure what example you can present of people "believing a guide blindly" nor am I sure where you can present a single instance of that somehow coming back to bite anyone?
And while Vattakaven has put a lot of time in, he hasn't put nearly as much as the guides I'm referring too. 

Lastly, trust who you wish but my point is that because they don't publish a paper that they are somehow not as knowledgeable as a researcher is wrong. From my first hand experience there is no one that knows the nuisances of these big cats better. And I'd bet good money that if you spoke with any of these researchers you named, they'd give credit right away to these guides and trackers they work with.

You can watch that video and see what he says. I believe naturally, that he knows better what he is talking about than you or me. These zoologists have way more first hand experience than you will ever have. They also have met more these safari guides than you and hear more stories from them than you. So you can count on it, that I trust to them more, when talking about certain things, like weights, success rates and so on. It´s simply not possible to be at same level when experiencing things only as a tourist. I think, that people like Vattakaven and Karanth are way more competent to estimate what stories are reliable and what aren´t.

So this isn´t a debate really. I just showed, as I said, other side of the coin so to say. I happen to know how good story tellers some guides are, when they are with tourists. Without modern science and objective zoologists there would be a lot of rubbish told as real things.
When did I say that you or I or any tourist has as much knowledge as the researchers mentioned?
I said the guides/locals. But we've made our points, time to move.
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Parks are opening back up!
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( This post was last modified: 10-21-2020, 09:33 AM by peter )

WILDLIFE PHOTOGRAPHER OF THE YEAR 2020 - SERGEY GORSHKOV

This great photograph of an Amur tigress hugging a Manchurian fir was taken in the Land of the Leopard National Park in the southwestern part of Sichote-Alin (Russia). 

The title is 'The Embrace':


*This image is copyright of its original author


More nice photographs: 

https://www.theatlantic.com/photo/2020/1...20/616710/
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( This post was last modified: 05-12-2021, 09:32 AM by peter )

ON THE SIZE OF AMUR TIGERS AND USSURI BROWN BEARS - PART I - RECENT INFORMATION

a - Introduction

A few days ago, our member 'Nyers' informed us about a new book on Amur tigers ('The uncrowned lord of the taiga') in the thread 'Amur tigers' (post 646). The online version (in Russian) is already available. The English translation will be published next year. The book, written by Yuri Dunishenko and Sergey Aramilev (General Director of the Amur Tiger Center) and published by the Amur Tiger Center, is based on recent scientific information. Both are undisputed authorities on wild Amur tigers, meaning the book is a 'must' for those interested in Amur tigers. 

The title of the new book no doubt will result in a few questions. Amur tigers and Ussuri brown bears more or less compare in head and body length, but Ussuri brown bears are more robust and heavier animals. For many, the question is who dominates who. 

Reliable information says male Amur tigers in particular hunt Ussuri brown bears up to the size of, and including, adult females. Some male Ussuri bears, and non-hibernating bears (also known as 'Schatuns' or 'Satellite' bears) in particular, however, follow, and sometimes hunt tigresses with cubs and immature tigers. It has to be added, however, that no such incidents have been recorded in the period 1992-2020.  

No incidents apart from two, I mean. One of them was an immature tigress found in the snow. Researchers arrived too late to get to solid conclusions. They assumed she had been killed by a bear, but the evidence they presented was inconclusive. Nearly all tigers killed by brown bears are eaten, but this tigress wasn't. In the period she was found, a number of Amur tigers had been affected by a disease. Some of those affected showed unusual behaviour. It could be she was one of them. 

There's no information about the second incident, but adult tigress 'Vera', also allegedly killed by a bear, is mentioned in an article about the (disadvantages of) Aldrich footsnares. The article, first published on a Russian forum, will be discussed in the near future.   

Interactions between males seem to be few. What we know, suggests male tigers and male brown bears avoid each other. A few incidents between large male brown bears and young adult male tigers have been described by Sysoev and Rukovsky. Their observations are considered as reliable, but most other stories about interactions between males of both species, as far as I know, have been dismissed. 

My guess is the situation won't change any time soon. The Russian Far East is a large and almost empty region. Most interactions between tigers and bears go unnoticed, that is. The only way to collect good information is to collar adult tigers and bears and monitor their behaviour for a prolonged period of time.        

b - A new document on Ussuri brown bears

Less than a year ago, a new document on Ussuri brown bears written by Seryodkin (IV), Kostyria (YK), Goodrich (JM) and Petrunenko (YK) was published in the Journal of Siberian Federal University Biology 12(4), Dec. 2019 (pp. 366-384): 'Space use by brown bears (Ursus arctos) in the Sichote-Alin'. It has an interesting table on the size of Ussuri brown bears captured in the period 1993-2001. 

The abstract is in Russian and in English. Here's the scan of the English translation:  


*This image is copyright of its original author

Here's a scan of the table mentioned above: 


*This image is copyright of its original author

I used the table to get to 2 others: a table on adult male bears and a table on adult female brown bears. Bears III (a 2-3 year old male), IX (a 4-year old female) and XV (a 3-year old female) in the table above were not used for the tables on account of their age (immature).  

Here's the table on adult females. They averaged 181,17 cm in total length (most probably measured 'over curves') and 163,75 kg (361 pounds). The sample, however, is very small:


*This image is copyright of its original author

And here's the table on adult males. They averaged 211,63 cm in total length (most probably measured 'over curves') and 257,50 kg (almost 568 pounds). The heaviest male (No. V) was weighed in May. It's very likely he would have been over 400 kg. in late autumn: 


*This image is copyright of its original author

The difference between young adults (5-8 years of age) and mature adults (9 years and over) is pronounced. Mature bears are not longer, but heavier. In males in particular, the difference is outspoken. Individual variation in both males and females is significant. 

c - More information on the size of Ussuri brown bears

A decade ago, on the former AVA Forum (now Tapatalk), an article written by N. Kucherenko (published in a Russian magazin in 2003) was discussed more than once. The reason was it has a table on the size of adult Ussuri brown bears. I'm referring to this well-known table:


*This image is copyright of its original author

The table is a bit suspect (it isn't likely that 10 adult males ranging between 260 and 321 kg produce an average of 264 kg), but the confusion could be a result of a typo (likely). 

Both male (196 cm as opposed to 211 cm) and female (160 cm as opposed to 181 cm) bears seem to have been somewhat shorter (referring to total length) in Kucherenko's day, but that could have been a result of coincidence or the method used to measure them. The difference between measurements taken 'over curves' and measurements taken in a straight line is considerable in brown bears (see -d-). Another disadvantage of this method (referring to a measurement taken 'over curves') is it can be applied in different ways.   

The main difference between both tables, however, is the difference in (average) weight. Kucherenko's females in particular were significantly heavier. The difference could have been a result of the aim of his paper (written to lure hunters to the Russian Far East), but it's also likely large individuals were more common back then. In the first decades after WWII, bears were not often hunted. 

There's more information about exceptional female brown bears in a few threads of the former AVA Forum (now Tapatalk). A member from China (KTKC) posted what seemed to be reliable information on a few large females. Here's a scan of one of his posts. The female brown bear, from northeastern China, was 275 kg:


*This image is copyright of its original author

Some years ago, another document on Ussuri brown bears was published. Seryodkin was involved in that one as well. Here's a scan of table 1. Two of the three male brown bears were collared in the Sichote-Alin Nature Reserve. The young adult male (6-7 years of age) was 180 kg, whereas the adult male (8-10 years of age) was 235 kg: 


*This image is copyright of its original author

d - Difference between curve and straight line measurements in brown bears

The two iriginal tables posted above (see -b-) say adult female Ussuri brown bears average 181,17 cm in length, whereas adult males average 211,63 cm: a difference of 30,46 cm (almost 1 foot). Assuming they, like most brown bears, were measured 'over curves', the question is how long they were in a straight line. This is necessary in order to be able to compare them to adult wild Amur tigers. 

Unfortunately, there's no information about the length of Ussuri brown bears measured in a straight line. Assuming they more or less compare to brown bears in the Americas, the question is if there's a bit more about American bears. The answer is affirmative. 

About a decade ago or so, I scanned and printed a table about the dimensions of American brown bears posted in a thread of AVA (now Tapatalk). As a result of problems with the PC, I lost a lot of information. This means I'm unable to tell you anything about the source of the table. The print, however, survived. Here it is:


*This image is copyright of its original author
 
The table has detailed information about the dimensions of male grizzly bears by age class measured in the period 1975-1985. My guess is the table is about brown bears captured in Yellowstone, but I could be mistaken. 

Anyhow. We're interested in 'Length (A)' and 'Contour length (A1)'. Length (A) is the straight line length, whereas contour length (A1) is the total length measured 'over curves' ('contours'). In adult male grizzly bears, that is to say bears of 5 years and older (bottom of the table), the average difference between both methods is 32,2 cm (164,3 cm as opposed to 196,5 cm). 

The question is if male grizzly bears can be considered as adult at age 5. My guess is most authorities consider a male brown bear as adult when he reaches 8-9 years of age. Males of 5-7 years of age would be considered as young adults. In order to be able to compare American male grizzly's with male Ussuri brown bears (see the table in -b-), I only used male grizzly's of 8 years and older in order to get to a comparison. 

The conclusion is the average difference between straight line and curve measurements in adult male grizzly's (8 years and older) is 36,2 cm per age class (range 7,5 - 60,9). There are significant differences between age classes. In two 13-year old male grizzly's, the average difference between both methods was 14,0 cm and in two 16-year old male grizzly's the average difference was 7,5 cm only, whereas it was as much as 60,9 cm in five 11-year old males. Strange.  

Anyhow. In 30 (the 15-year old bear was left out of the equasion as he was measured in a straight line only) adult male grizzly bears, the average difference between both methods was 36,2 cm (14,25 inches). 

Assuming they more or less compare to adult male Ussuri brown bears (a) and the method used to measure them 'over curves' ('contours') in the Russian far East was applied in the same way (b), the conclusion is adult male Ussuri brown bears, averaging 211,63 cm in total length measured 'over curves', are 175,43 cm measured in a straight line ©. Remember this conclusion is based on the averages of all age classes combined and every age class had the same weight in the equasion. Also remember individual variation in adult male brown bears is pronounced. 

The American male grizzly's, by the way, averaged 95,7 cm (range 83,0 - 105,0) in height and 135,1 cm (range 116,0 - 150,0) in chest girth. 

Do American male grizzly bears and Ussuri male brown bears, as was assumed (see above), really compare? Not quite. What I have suggests Ussuri male brown bears are a bit larger in all departments. 

The two 8-year old males weighed in October were just over 200 kg and the 8-year old weighed in May was 220 kg. The other four male bears, all weighed in the period May-September, averaged 298 kg (range 256 - 363 kg) or 657 pounds. Big by any standard.

e - Difference between curve and straight line measurements in Amur tigers

In this post, the focus isn't on Amur tigers (Panthera tigris altaica), but Indian tigers (Panthera tigris tigris). One reason is there is much more information on the length (and weight) of tigers shot in what used to be British India. Another is there is good information about the methods used to measure tigers in that part of the world in both magazins and books. 

Tiger hunting always was quite popular in British India. From 1860 onward, the number of hunters more or less exploded. A few decades and tens of thousands of dead tigers later, hunters concluded regulation was badly needed in order to prevent total destruction. This, mind you, was well before the turn of the century (referring to the period 1880-1900). 

In this respect (the destruction of the natural world), British India and Russia (referring in particular to the regions, ehh, aquired from China in 1858 and 1860 (nowadays the Russian Far East) definitely compared. 

If you want to know more about the situation in the Russian Far East, my advice is to read 'Taming tiger country: Colonization and environment of the Russian Far East, 1860-1940'. The dissertation of Mark Sokolsky (2016) is extensive and very interesting. 

Here's a map showing the territory gained by Russia in 1858 and 1860: 


*This image is copyright of its original author

The destruction of the natural world in the Russian Far East is also described in 'Dersu The Trapper'. In the first decade of the 20th century, Vladimir Klavdievich Arseniev and his guide Dersu thought the slaughter they saw would result in mass extinctions in a few decades only. They were right. In the twenties and thirties of the last century, Amur tigers (as well as many other species) really walked the edge. It was a close call.  

Returning to British India, tigers and the methods used to measure them. As far as I know, only Forest Officers and a few experienced hunters measured tigers in a straight line in the period 1860-1890. Nearly all tigers shot in that period were measured 'over curves', that is. As this method, which can be applied in different ways, not seldom produced tigers of exceptional length, debates about the reliability of these records erupted quite often. 

Sterndale ('Natural history of the mammalia of India and Ceylon', 1884, pp. 162-163) was the one who proposed to measure tigers in a different way. His proposal to measure tigers in a straight line ('between pegs') was adopted in most parts of Central India, but in northern India, Assam and southern India many hunters continued to measure tigers 'over curves'. 

Here's a scan of pages 162-163 of his book:


*This image is copyright of its original author

The Maharajah of Cooch Behar ('Thirty-seven years of big game shooting in Cooch Behar, the Duars, and Assam. A rough diary', Bombay, 1908) and his guests measured all tigers they shot in the period 1870-1908 'over curves'. Just before and after the turn of the century (1898-1902), however, 12 male tigers were measured 'between pegs'. Of these, 10 were measured both 'over curves' and between pegs':


*This image is copyright of its original author

The table, which has one error (the tigers were shot in the period 1889-1902 and not in the period 1989-1902), was posted in this thread in January 2016. It shows the average difference between both methods in 10 male tigers shot in the period 1889-1902 was 5,45 inches or 13,84 cm (range 5-7 inches). These 10 tigers, largely as a result of one long tiger, averaged 290,17 cm in total length measured 'over curves' (range 274,32 - 317,50) and 276,35 cm 'between pegs' (range 261,62 - 300,99). The average head and body length of 9 males was 199,53 cm measured 'over curves' (range 186,69 - 210,82). Of these 10 males, 8 were weighed, of which one was 'gorged'. They averaged 455 pounds (range 385 - 504) or 206,39 kg.

Compared to the average of all male tigers shot in the period 1877-1908 (n=89) in that part of British India, they were a bit shorter (290,19 cm as opposed to 294,84 cm). They also lacked a little over 6 pounds (455 as opposed to 461,34). Not one of the 89 males measured and the 53 weighed, by the way, was exceptional.   

Why is this table posted in a post about the length of wild male Amur tigers? The reason is it, to a degree, can be compared to a table with the dimensions of 13 wild male Amur tigers captured in the Sichote-Alin Biosphere Reserve in the period 1992-2004. 

I'm referring to Table 7.3 in 'Tigers in the Sichote-Alin Zapovednik: Ecology and conservation' (Miquelle (DG), Smirnov (EN) and Goodrich (JM), 2005). This publication is in Russian only, but the table is in English as well: 


*This image is copyright of its original author

The tigers captured in this reserve were measured in the same way as the tigers shot in Cooch Behar, the Duars and Assam in the period 1870-1908 ('over curves'). The conclusion is they, in total length, more or less compared to the 10 male tigers shot in northeastern India a century ago (294,00 cm as opposed to 290,19 cm). 

If the method used in Russia in the period 1992-2004 was applied in the same way as in northeastern India in the period 1870-1908, it means we have to deduct 5,45 inches (13,84 cm) from the total length 'over curves' to get to the total length measured in a straight line ('between pegs'). The result (294,00 - 13,83 = 280,17 cm) suggests wild male tigers shot in northeastern India in the period 1870-1908 and wild male Amur tigers captured in the Sichote-Alin Biosphere Reserve in the period 1992-2004 more or less compared in total length 'between pegs'. 

Male tigers shot in Central India in about the same period as the tigers shot in northeastern India (refering to 'Wild animals in Central India', A.A. Dunbar-Brander, 1923) were a tad longer (281,94 cm in total length measured 'between pegs'), but the sample from Central India was larger and it included a few very large individuals. Lengthwise, one could, therefore, conclude there's little to choose between male tigers shot in northeastern (n=10) and Central (n=42) India about a century ago and male tigers captured in the Sichote-Alin Reserve (n=13) in the period 1992-2004. 

Wild male tigers shot in Central India averaged 420 pounds (190,51 kg), whereas those shot in northeastern India averaged 461 pounds (209,11 kg). In order to find out more about the weight of wild male Amur tigers captured a century later, we need more information. 

Here's a table with more details about 10 wild Amur tigresses and 11 wild male Amur tigers. It's very likely these 11 males featured in the previous table as well, but I'm not sure. As a result of the problems mentioned above (referring to computer crashes that resulted in a significant loss of information), I'm also unable to tell you anything about the source of the table. I only remember it was posted in one of the threads of the former AVA Forum (now Tapatalk):     


*This image is copyright of its original author

When reading the table, one has to remember it includes tigers of 3 years and over. A wild male tiger of that age is considered as adult (as it's able to reproduce), but the information I have on weights, lengths and, in particular, skulls shows there are significant differences between young adult male tigers (3-4 years of age) and mature males (5 years and over).  

Of the 11 male tigers in the table, four ('Alexei', 'Misha', 'Andrew' and 'Jack-2') were either immature or in bad health. One of them (I think it was 'Andrew', but I'm not sure) was in such bad shape he had to be euthanized. 

Tiger 'Victor', who also made the table, was found in a snare by wildlife students in February 2004. He was sedated and taken to a small enclosure in Terney to recover. A few days later, he was released back into the wild. Although not as large as others, 'Victor', a mature male estimated to be 8-10 years of age, was 288 cm in total length measured 'over curves'. At 385 pounds (174,64 kg), he was described as " ... unusually fat and healthy ... " ('Against all odds', John Goodrich, 2004). 

Tiger 'Dima', known for his preference for brown bears, was captured 3 times. The first time, he was 205 kg. Some time later, after he had lost 3 canines, he was 170 kg on a full stomach (...). The third time he was captured, he was 204 kg. He entered the table at 193 kg (205 + 170 + 204 = 579 : 3 = 193). 

So what is the average weight of a wild male Amur tiger these days? The answer we don't know. 

Those who expressed their opinion ranged between 389 (Slaght et al., 2005) and 430 (Miquelle) pounds, but the 11 male Amur tigers in the table above averaged 169,45 kg (range 125-200) or 373 pounds. If we remove the young adults and the tiger that was euthanized, the average of the remaining 7 males is 184,45 kg (range 170-200) or 406 pounds. The measurements suggest tiger 'Volodya'  could have been a young adult as well. Without him, the average is 186,83 kg (almost 411 pounds).  

An average is a result of selection and sample size. As to the sample. It's smallish, but it's the only one available. We have no option but to use it, that is. As to selection: the question is if males affected by natural conditions should be included or not. In a region known for tough conditions like the Russian Far East, one, I think, has to include the effect of these conditions, as it's the only way to produce an informative, and reliable, table. 

For those interested in a table that has healthy adult males only: my guess for now is healthy adult (5 years and older) males range between 160-254 kg (354-563 pounds). Both limits are not a result of guesswork only. 

Tiger 'Dima' mentioned above was 205 kg (452 pounds) when he had all his canines. Some time later, when he had lost 3, he was 170 kg (375 pounds) only. That, mind you, was on a full stomach. Without the roedeer he had eaten, he would have been about 350 pounds, if not less. In spite of his problems (referring to the 3 canines he lost and to his weight when he was recaptured), he made a full recovery: the last time he was weighed, he was 204 kg. The average for the 3 captures was 193 kg (426 pounds). This means the range in weight of a healthy adult male Amur tiger can be quite significant. 

The heaviest wild male Amur tiger accepted by biologists was the male shot by Baikov near the Korean border in 1911. That male was 254 kg (563 pounds). The heaviest captured in the period 1992-2021 was 'Luk'.  

Although quite heavy (212 kg or 468 pounds) for his length, 'Luk' still had some growing to do when he was captured. The photographs published show a compact tiger, but 'Luk', a young adult, was (significantly) shorter than average. This is important, as there was a strong relation between total length and weight in adult wild male tigers shot in northern and northeastern India about a century ago: male tigers exceeding 440 pounds were significantly longer (and heavier) than male tigers below that mark (440 pounds). As there's no reason to assume it would be different today (or in other regions), it seems quite safe to assume 'Luk', all other factors equal, would have been longer and heavier in his prime. 

Heel width also is a factor to consider. What is known, strongly suggests there could be a (strong) relation between heel width and weight in adult wild male tigers (same in captive male Amur tigers). In this department as well, tiger 'Luk', if I remember correctly, wasn't exceptional. In heel width, adult wild male Amur tigers range between 10,0-12,5 cm. Exceptional individuals can reach, and at times exceed, 13,0 cm. A heel width of 13,5 cm has been measured more than once and captive male Amur tigers (referring to previous posts in this thread) can reach 14,1 cm. 

I can almost hear you say my proposal regarding the average is a bit confusing as both historic and modern records were used. Furthermore, there's no real average, only a range, and a very wide one (165-254 kg) at that. 

I agree on all points made. I could have used weights of male Amur tigers captured in the period 1992-2021 only. Furthermore, the tigers captured in that period were measured in the same way and weighed with the same machine. Another problem solved. In spite of that, I decided against it. One reason is the sample is small. Another is the sample included young adults and problem tigers. When the sample is smallish, both factors would have a serious effect. I'm not saying it would result in misinformation, but it could result in an incorrect picture.  

The problem described, unfortunately, isn't easy to solve. The reason is a lack of data. My guess is the situation isn't going to change any time soon. Biologists, for good reasons (referring to the article on the results of footsnares published on a Russian forum some years ago), seem more reluctant to capture adult male tigers with Aldrich footsnares.  The only wild Amur tigers captured today are orphaned cubs, immature (or young adult) tigers causing problems and (old) tigers affected by disease. If we want to know more about the length and weight of healthy adults in their prime, we have no option but to use information published in the period 2000-2010. 

And that's it? Well, apart from historic records, we could use observations of experienced rangers and biologists. The problem is it's very difficult to get to an accurate estimate. And an estimate it will be, no matter what. Measurements of heel width, most probably, are more informative. And then there's camera traps. It would be best to combine sightings, camera trap pictures and measurements (referring to heel width), but chances are it won't happen very often. 

Every now and then, pictures of large individuals are published. The pictures below show wild male Amur tigers possibly exceeding tiger 'Luk' (the young adult male of 212 kg) in length and weight, but remember it's only an opinion.

Here's a recent picture (2021) of a thick-set male from Anyuisky National Park (Chabarowsky Krai). The female also isn't small:


*This image is copyright of its original author
 
Frontal view of a robust male seen on a road well west of all reserves (2019). This photograph was first posted by our former mod 'Wolverine':  


*This image is copyright of its original author

This photograph shows a male hugging a smell tree. I don't think he was exceptional, but it was a muscular male tiger:  


*This image is copyright of its original author
 
This photograph (camera trap as well) shows a male clearly surprised. The heel width of this 'monster' tiger (assessment of the man able to get to a comparison) was exceptional (13,5 cm):


*This image is copyright of its original author
 
One more (2019) to finish this overview of large male Amur tigers not weighed by biologists: 


*This image is copyright of its original author


As to the weight of large males. We can only guess, but chances are one or two might be quite close to the heaviest male Amur tiger accepted by biologists today. This male, shot near the Korean border in 1911 by Baikov, was 254 kg (560 pounds) and 11.8 (355,12 cm) in total length (see the picture below). 

A male Amur tiger with a total length of of 355,12 cm? I agree it's remarkable, especially when we know the longest captive males actually measured were about 10.6 in total length in a straight line. 

My guess is the skin was measured after it was removed. The giant tiger shot near the Sungari river in 1943 was 11.6 'over curves' in total length (350,52 cm). When the skin was removed, it taped 375 cm (12.4). If we deduct 10 inches from the length of the skin of the tiger shot in 1911 as well, the outcome is 10.10. This could have been the total length measured 'over curves'. Measured in a straight line, the tiger, most probably, was 10.2-10.4. About as long as the longest captive Amur tigers: 


*This image is copyright of its original author
 
Was this tiger longer and more robust than the males shown above? We'll never know, but my guess is the difference is limited. Any chance of capturing a tiger of this size one day? Not likely. As far as I know, at least 2 males were able to break the binding or, worse, get out of the footsnare when rangers and biologists approached. Two biologists were attacked, but the damage, most fortunately, was (relatively) limited. I'm not saying it's impossible to capture a male tiger exceeding 450 pounds with a footsnare (far from it), but you never know.     
 
This regarding the size of wild male Amur tigers measured and weighed by biologists in the period 1992-2021. 

And what about the size of wild Amur tigers shot in the period 1880-1945? The document published in 2005 and discussed above has a table with 'historic' records as well. Those who had the opportunity to go over them, to keep it short, concluded most records are unreliable. 

A justified conclusion? 

I think so. I agree something more than a newspaper report or a vague photograph is needed to accept a record of a tiger of exceptional size. It is, however, quite another thing to reject most hunting records as products of hearsay only. Dismissing them out of hand would be as unwise as accepting them without solid proof. 

Wild Amur tigers today, most probably as a result of the population bottleneck in the first decades of the last century, do not show the same amount of individual variation seen in other subspecies. This is not true for captive Amur tigers. The remarkable size of some individuals suggests hunting records should be taken a bit more serious. A lack of reliable information doesn't mean large tigers were a result of imagination only. 

The tiger below, for example, was very real. Jankowski informed V. Mazak about the tiger and sent him a unique photograph. Mazak wrote about the tiger in the third edition of his book published in 1983. Less than a decade later, Jankowski's book was published. The tiger was mentioned in his book as well. 

In spite of all that, the tiger never made it to a table. I agree it's an effective way of eliminating a record, but it makes you wonder about those going over historic records. Did they miss him completely, or did they decide he, for some reason, didn't qualify? The remains of the large male bear he had killed and eaten, by the way, were erased as well. By those convinced adult male brown bears are out of the predatory reach of adult male Amur tigers of similar size. They did a great job, but reliable reports about brown bears killed by tigers keep coming in and the bears killed are not as small as most assumed. 

The Sungari River tiger shot in 1943 wasn't weighed, but estimated at 300-350 kg. If we deduct the bear he had eaten, he could have been as heavy as exceptional captive male Amur tigers seen every now and then (250-300 kg, possibly a bit more). 

Here's a scan of the photograph published in Mazak's book. Notice the size of the skull:  


*This image is copyright of its original author

     
Apart from hunting records, there is information about the size of wild Amur tigers found dead in the period 1970-1994. I'm referring to Table 1 in 'Conflicts between man and tiger in the Russian Far East' (Nikolaev (IG) and Yudin (VG), 1993). 

Of the 38 male tigers in that table, 26 were weighed. Of these, 21 were 3 years or older (range 3,5 - 13). They averaged 159,8 kg (range 93-192). The tiger of 93 kg (200 pounds), 6-7 years of age, had a bullet wound. It's very likely he died as a result of starvation. The tiger of 192 kg (424 pounds) died shortly after a fight with another male. He suffered from a pathology of the paw and was no match for his opponent. 

As to the cause of death of these 38 males. 

At least 24 of these 38 tigers had been shot. Most were killed directly, but some (like the 93 kg tiger) survived, only to perish later. One was trapped and another tiger was poisoned. One male was killed by a bear near Komissarovska in 1972 (no information available) and another was killed by a wild boar near Vasilkovka in 1984. In 1985, near Terney, a tiger of 178 kg was severely injured by a horse. He drowned in a river when the ice broke. At least 5 tigers suffered from leg or paw injuries. In 2 males, it was the result of a disease. The others most probably were injured in a fight. Although (brown) bears could have been involved, tigers can't be excluded. I've seen different serious fights between captive tigers and noticed paw and leg injuries are not uncommon. It could be wild tigers also deliberately target paws and legs in a fight.     

As to the age wild Amur tigers can reach. 

One seldom reads anything about old tigers in the Russian far East. Of the 38 male tigers found dead in the period 1970-1994 (referring to the table of Nikolaev and Yudin discussed in the previous paragraph), four were 10 years or older. Three of them were weighed. The 10-year old male was 192 kg, whereas the older males were 136 and 168 kg. 

Wild Amur tigers exceeding 12 years of age seem to be few and far between. I know of a female of 15 and read a newspaper article about a wild male tiger estimated at 15 years of age in the Siberian Times of 16-01-2019 ('Tiger king Tikhon who sought human help wants to return to the wild after having dental treatment'). According to the reporter, tiger 'Tikhon' visited A Russian border post in January 2019. He said he needed to see a dentist. As he insisted, they decided to help him. The dentist did all he could, but it was clear 'Tikhon', who had lost most of his teeth, was unable to continue his career in the wild. Although starving, 'Tikhon' strongly disagreed with the decision. A few weeks later, however, he perished. At 140 kg only (in another newspaper article he was 142 kg), he was thin as a rail: 


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author

The conclusion, to finish this paragraph, is 11 adult wild male Amur tigers captured in the Sichote-Alin Biosphere Reserve in the period 1992-2004 averaged 294 cm in total length measured 'over curves' (about 280-281 cm 'between pegs) and 169-170 kg. 

Without the young adults (n=3) and the tiger euthanized later (n=1), the remaining 7 males averaged 298-299 cm in total length measured 'over curves' (range 288-308) and 184-185 kg (range 170-200). These 7 males averaged 198 cm (range 190-208) in head and body length (also measured 'over curves'), 124-125 cm (range 113-130) in chest circumference and 81-82 cm (range 78-85) in head circumference.  

In head and body length measured in a straight line, they averaged 183-184 cm (198 - 14). The 8 male Ussuri brown bears discussed above averaged about 175 cm in total length measured in a straight line. If the tail was included (likely), it means they averaged about 165 cm in head and body length measured in a straight line. Male Amur tigers, therefore, are about 15-20 cm longer in head and body. 

The main difference between both species is in weight: adult (8 years and over) male brown bears captured about 2 decades ago averaged 257-258 kg (see the table above), whereas adult male Amur tigers (referring to the 7 males discussed above) captured in roughly the same period averaged about 184-185 kg, maybe a bit more (190-195 kg). 

All in all, the conclusion is adult male Ussuri brown bears, although a bit shorter, have a weight advantage of about 70-75 kg at the level of averages. If we add the also have longer necks and (slightly) longer skulls, the conclusion is their body is very compact and robust.  

f - Individual variation in wild Amur tigers

There is plenty of information about individual variation in wild male brown bears, but not quite enough on wild male Amur tigers. What is known, will be described in the continuation of the series on the size of wild Amur tigers and Ussuri brown bears. 

It won't be the second post of the series, though. I first want to tell you a bit more about the size of captive Amur tigers in European and Chinese zoos and facilities. One reason is there's good information about the size of captive Amur tigers in European and Chinese zoos. Although captive Amur tigers usually are a bit larger than their wild relatives, they offer a bit more insight in the potential of Amur tigers. Another reason is I recently received reliable information about the size of adult Amur tigers in 2 Chinese facilities from our member 'Betty'.
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(11-20-2020, 03:45 PM)peter Wrote: THE USSURI BROWN BEAR OR BLACK GRIZZLY (Ursus arctos lasiotus) - NEW INFORMATION ON LENGTH AND WEIGHT 

a - Introduction

A few days ago, our member 'Nyers' informed us about a new book on Amur tigers ('The uncrowned lord of the taiga') in the thread 'Amur tigers' (post 646). The online version (in Russian) is already available. The English translation will be published next year. The book, written by Yuri Dunishenko and Sergey Aramilev (General Director of the Amur Tiger Center) and published by the Amur Tiger Center, is based on recent scientific information. Both are undisputed authorities on wild Amur tigers, meaning the book is a 'must' for those interested in Amur tigers. 

The title of the new book no doubt will result in a few questions. Amur tigers and Ussuri brown bears more or less compare in head and body length, but Ussuri brown bears are more robust and heavier animals. For many, the question is who dominates who. 

Reliable information says male Amur tigers in particular hunt Ussuri brown bears up to the size of, and including, adult females. Some male Ussuri bears, and non-hibernating bears ('Schatuns' or satellite bears) in particular, however, follow, and sometimes hunt tigresses with cubs and immature tigers. It has to be added, however, that no such incidents have been recorded in the period 1992-2020.  

No incidents apart from two, I mean. One of them was an immature tigress found in the snow. Researchers arrived too late to get to solid conclusions. They assumed she had been killed by a bear, but the evidence they presented was inconclusive. Nearly all tigers killed by brown bears are eaten, but this tigress wasn't. In the period she was found, a number of Amur tigers had been affected by a disease. Some of those affected showed unusual behaviour. It could be she was one of them. 

There's no information about the second incident, but adult tigress 'Vera', also allegedly killed by a bear, is mentioned in an article about the (disadvantages of) Aldrich footsnares. The article, first published on a Russian forum, will be discussed in the near future.   

Interactions between males seem to be few. What we know, suggests male tigers and male brown bears avoid each other. A few incidents between large male brown bears and young adult male tigers have been described by Sysoev and Rukovsky. Their observations are considered as reliable, but most other stories about interactions between males of both species, as far as I know, have been dismissed. 

My guess is the situation won't change any time soon. The Russian Far East is a large and almost empty region. Most interactions between tigers and bears go unnoticed, that is. The only way to collect good information is to collar adult tigers and bears and monitor their behaviour for a prolonged period of time.        

b - A new document on Ussuri brown bears

Less than a year ago, a new document on Ussuri brown bears written by Seryodkin (IV), Kostyria (YK), Goodrich (JM) and Petrunenko (YK) was published in the Journal of Siberian Federal University Biology 12(4), Dec. 2019 (pp. 366-384): 'Space use by brown bears (Ursus arctos) in the Sichote-Alin'. It has an interesting table on the size of Ussuri brown bears captured in the period 1993-2001. 

The abstract is in Russian and in English. Here's the scan of the English translation:  


*This image is copyright of its original author

Here's a scan of the table mentioned above: 


*This image is copyright of its original author

I used the table to get to 2 others: a table on adult male bears and a table on adult female brown bears. Bears III (a 2-3 year old male), IX (a 4-year old female) and XV (a 3-year old female) were not used for the tables on account of their age (immature).  

Here's the table on adult females. They averaged 181,17 cm in total length (most probably measured 'over curves') and 163,75 kg (361 pounds). The sample, however, is very small:


*This image is copyright of its original author

And here's the table on adult males. They averaged 211,63 cm in total length (most probably measured 'over curves') and 257,50 kg (almost 568 pounds). The heaviest male (No. V) was weighed in May. It's very likely he would have been over 400 kg. in late autumn: 


*This image is copyright of its original author

The difference between young adults (5-8 years of age) and mature adults (9 years and over) is pronounced. Mature bears are not longer, but heavier. In males in particular, the difference is outspoken. Individual variation in both males and females is significant. 

c - More information on the size of Ussuri brown bears

A decade ago, on the former AVA Forum (now Tapatalk), an article written by N. Kucherenko (published in a Russian magazin in 2003) was discussed more than once. The reason was it has a table on the size of adult Ussuri brown bears. I'm referring to this well-known table:


*This image is copyright of its original author

The table is a bit suspect (it isn't likely that 10 adult males ranging between 260 and 321 kg produce an average of 264 kg), but the confusion could be a result of a typo (likely). 

Both males (196 cm as opposed to 211 cm) and females (160 cm as opposed to 181 cm) seem to have been somewhat shorter (referring to total length) in Kucherenko's day, but that could have been a result of the method used to measure them. The difference between measurements taken 'over curves' and measurements taken in a straight line is considerable in brown bears (see -d-). Another disadvantage of this method (referring to a measurement taken 'over curves') is it can be applied in different ways.   

The main difference between both tables, however, is the difference in (average) weight. Kucherenko's females in particular were significantly heavier. The difference could have been a result of the aim of his paper (written to lure hunters to the Russian Far East), but it's also likely large individuals were more common back then. In the first decades after WWII, bears were not often hunted. 

There's more information about exceptional female brown bears in a few threads of the former AVA Forum (now Tapatalk). A member from China (KTKC) posted what seemed to be reliable information on a few large females. Here's a scan of one of his posts. The female brown bear, from northeastern China, was 275 kg:


*This image is copyright of its original author

Some years ago, another document on Ussuri brown bears was published. Seryodkin was involved in that one as well. Here's a scan of table 1. Two of the three male brown bears were collared in the Sichote-Alin Nature Reserve. The young adult male (6-7 years of age) was 180 kg, whereas the adult male (8-10 years of age) was 235 kg: 


*This image is copyright of its original author

d - Difference between curve and straight line measurements in brown bears

The two iriginal tables posted above (see -b-) say adult female Ussuri brown bears average 181,17 cm in length, whereas adult males average 211,63 cm: a difference of 30,46 cm or about 1 foot. Assuming they, like most brown bears, were measured 'over curves', the question is how long they were in a straight line. This is necessary in order to be able to compare them to adult wild Amur tigers. 

Unfortunately, there's no information about the length of Ussuri brown bears measured in a straight line. Assuming they more or less compare to brown bears in the Americas, the question is if there's a bit more about American bears. The answer is affirmative. 

About a decade ago or so, I scanned and printed a table about the dimensions of American brown bears posted in a thread of AVA (now Tapatalk). As a result of problems with the PC, I lost a lot of information. This means I'm unable to tell you anything about the source of the table. The print, however, survived. Here it is:


*This image is copyright of its original author
 
The table has detailed information about the dimensions of male grizzly bears by age class measured in the period 1975-1985. My guess is the table is about brown bears captured in Yellowstone, but I could be mistaken. 

Anyhow. We're interested in 'Length (A)' and 'Contour length (A1)'. Length (A) is the straight line length, whereas contour length (A1) is the total length measured 'over curves' ('contours'). In adult male grizzly bears, that is to say bears of 5 years and older (bottom of the table), the average difference between both methods is 32,2 cm (164,3 cm as opposed to 196,5 cm). 

The question is if male grizzly bears can be considered as adult at age 5. My guess is most authorities consider a male brown bear as adult when he reaches 8-9 years of age. Males of 5-7 years of age would be considered as young adults. In order to be able to compare American male grizzly's with male Ussuri brown bears (see the table in -b-), I only used male grizzly's of 8 years and older in order to get to a comparison. 

The conclusion is the average difference between straight line and curve measurements in adult male grizzly's (8 years and older) is 36,2 cm per age class (range 7,5 - 60,9). There are significant differences between age classes. In two 13-year old male grizzly's, the average difference between both methods was 14,0 cm and in two 16-year old male grizzly's the average difference was 7,5 cm only, whereas it was as much as 60,9 cm in five 11-year old males. Strange.  

Anyhow. In 30 (the 15-year old bear was left out of the equasion as he was measured in a straight line only) adult male grizzly bears, the average difference between both methods was 36,2 cm (14,25 inches). 

Assuming they more or less compare to adult male Ussuri brown bears (a) and the method used to measure them 'over curves' ('contours') in the Russian far East was applied in the same way (b), the conclusion is adult male Ussuri brown bears, averaging 211,63 cm in total length measured 'over curves', are 175,43 cm measured in a straight line ©. This conclusion, however, is based on averages of age classes, whereas individual variation in adult male brown bears is pronounced. 

The American male grizzly's, by the way, averaged 95,7 cm (range 83,0 - 105,0) in height and 135,1 cm (range 116,0 - 150,0) in chest girth. 

Do American male grizzly bears and Ussuri male brown bears, as was assumed (see above), really compare? Not quite. What I have suggests Ussuri male brown bears are a bit larger in all departments. 

The two 8-year old males weighed in October were just over 200 kg and the 8-year old weighed in May was 220 kg. The other four male bears, all weighed in the period May-September, averaged 298 kg (range 256 - 363 kg) or 657 pounds. Big by any standard.

e - Difference between curve and straight line measurements in Amur tigers

In this post, the focus isn't on Amur tigers (Panthera tigris altaica), but Indian tigers (Panthera tigris tigris). One reason is there is much more information on the length (and weight) of tigers shot in what used to be British India. Another is there is good information about the methods used to measure tigers in that part of the world in both magazins and books. 

Tiger hunting always was quite popular in British India. From 1860 onward, the number of hunters more or less exploded. A few decades and tens of thousands of dead tigers later, hunters concluded regulation was badly needed in order to prevent total destruction. This, mind you, was well before the turn of the century (referring to the period 1880-1900). 

In this respect (destruction of the natural world), British India and Russia (referring in particular to the regions, ehh, aquired from China in 1858 and 1860 (nowadays the Russian Far East) definitely compared. 

If you want to know more about the situation in the Russian Far East, my advice is to read 'Taming tiger country: Colonization and environment of the Russian Far East, 1860-1940'. The dissertation of Mark Sokolsky (2016) is extensive and very interesting. 

Here's a map showing the territory gained by Russia in 1858 and 1860: 


*This image is copyright of its original author

The destruction of the natural world in the Russian Far East is also described in 'Dersu The Trapper'. In the first decade of the 20th century, Vladimir Klavdievich Arseniev and Dersu thought the slaughter they saw would result in mass extinctions in a few decades only. They were right. In the twenties and thirties of the last century, Amur tigers (as well as many other species) really walked the edge.  

Returning to British India, tigers and the methods used to measure them. As far as I know, only Forest Officers and a few experienced hunters measured tigers in a straight line in the period 1860-1890. Nearly all tigers shot in that period were measured 'over curves', that is. As this method, which can be applied in different ways, not seldom produced tigers of exceptional length, debates about the reliability of these records erupted quite often. 

Sterndale ('Natural history of the mammalia of India and Ceylon', 1884, pp. 162-163) was the one who proposed to measure tigers in a different way. His proposal to measure tigers in a straight line ('between pegs') was adopted in most parts of Central India, but in northern India, Assam and southern India many hunters continued to measure tigers 'over curves'. 

Here's a scan of pages 162-163 of his book:


*This image is copyright of its original author

The Maharajah of Cooch Behar ('Thirty-seven years of big game shooting in Cooch Behar, the Duars, and Assam. A rough diary', Bombay, 1908) and his guests measured all tigers they shot in the period 1870-1908 'over curves'. Just before and after the turn of the century (1898-1902), however, 12 male tigers were measured 'between pegs'. Of these, 10 were measured both 'over curves' and between pegs':


*This image is copyright of its original author

The table, an original for Wildfact posted in this thread in January 2016, shows the average difference between both methods in 10 male tigers shot in the period 1898-1902 was 5,45 inches or 13,84 cm (range 5-7 inches). These 10 tigers, largely as a result of one long tiger, averaged 290,17 cm in total length measured 'over curves' (range 274,32 - 317,50) and 276,35 cm 'between pegs' (range 261,62 - 300,99). The average head and body length of 9 males was 199,53 cm measured 'over curves' (range 186,69 - 210,82). Of these 10 males, 8 were weighed, of which one was 'gorged'. They averaged 455 pounds (range 385 - 504) or 206,39 kg.

Compared to the average of all male tigers shot in the period 1877-1908 (n=89), they were a bit shorter (290,19 cm as opposed to 294,84 cm). They also lacked a little over 6 pounds (455 as opposed to 461,34). Not one of the 89 males measured and the 53 weighed was exceptional.   

Why is this table posted in a post about the length of wild male Amur tigers? The reason is it, to a degree, can be compared to a table with the dimensions of 10 wild male Amur tigers captured in the Sichote-Alin Biosphere Reserve in the period 1992-2004. 

I'm referring to Table 7.3 in 'Tigers in the Sichote-Alin Zapovednik: Ecology and conservation', Miquelle (DG), Smirnov (EN) and Goodrich (JM), 2005. This much discussed document is in Russian only, but the table is in English as well: 


*This image is copyright of its original author

The tigers captured in this reserve were measured in the same way as the tigers shot in Cooch Behar, the Duars and Assam in the period 1870-1908 ('over curves'). In total length, they more or less compared to the 10 male tigers shot in northeastern India a century ago (294,00 cm as opposed to 290,19 cm). 

If the method used in Russia in the period 1992-2004 was applied in the same way as in northeastern India a century ago, it means we have to deduct 5,45 inches (13,84 cm) from the total length 'over curves' to get to the total length in a straight line. The result (294,00 - 13,83 = 280,17 cm) suggest wild male tigers measured in northeastern India in the period 1870-1908 and wild male Amur tigers measured in the Sichote-Alin Biosphere Reserve in the period 1992-2004 more or less compared in total length 'between pegs'. 

As the wild male tigers shot and measured in northeastern India and those shot and measured in Central India in roughly the same period (referring to 'Wild animals in Central India', A.A. Dunbar-Brander, 1923), the conclusion, regarding total length 'between pegs', is there's little to choose between wild male tigers in northeastern (n=10) and Central India (n=42) on one hand and wild male Amur tigers on the other (n=10). 

Wild male tigers shot in Central India averaged 420 pounds (190,51 kg), whereas those shot in northeastern India averaged 461 pounds (209,11 kg). In order to find out more about the weight of wild male Amur tigers captured a century later, we need more information. 

Here's a table with more details about 10 wild Amur tigresses and 10 wild male Amur tigers. It could be they are the tigers used for the table above, but I'm not sure. As a result of the problems mentioned above (referring to crashes that resulted in the loss of information), I'm also unable to tell you the source of the table. I only remember it was posted in one of the threads of the former AVA Forum (now Tapatalk):     


*This image is copyright of its original author

To be continued.

Good posting, some remarks.

What comes to those weight of the bears it was interesting to see some new figures. When looking at male bears I found it quite interesting that out of sample of only eight bears, there were two which were pretty big ones. First was that bear weighed May 19th and weight was 363 kg. By getting only 10% weight increase it would be a 400 kg bear which is a lot for so called ”inland grizzly”. I dare to claim, that just before hibernation it could weight at least anything in between 400-440 kg. To compare with biggest weighed wild bears ever in Scandinavia and Finland heaviest bear has been 372 or 373 kg (I always forget which was exact number).

Another big bear was weighed July 19th and 305 kg. What makes it interesting is, that while people often think that bears are in their lightest condition right after hibernation it isn´t the whole story. Some bears can be, but many are as light as they are right after mating time. Male bears move hundreds of kilometers while searching female bears to mate and they are quite aggressive and naturally fighting for mating rights. So a bear weighed in July can be pretty light when comparing what it is before hibernation. A 300 kg in July bear can be expected to gain 100 kg more weight before it starts to hibernate without being unrealistic. It can be less or more, but that bear could be in November something like 375-415 kg, imo.

I find this interesting also because of the study I noticed recently concerning brown bears living in Hokkaido (I shared it in brown bears thread). They are considered by some to be same subspecies as Ussuri brown bears and some think, that different population. They had a lot of bears around 400 kg and a few even bigger (up to 520 kg). These things seem to back up claims, that Ussuri brown bears are, what comes to size, somewhere in between ”normal” inland brown bears and brown bears with access to salmon rivers. While Hokkaido brown bears have been quite isolated it´s natural to assume that the bears living in Russian far east have more genetic variation nowadays. But maybe still producing some really big ones more often than most other brown bear subspecies/populations.


Then what comes to that one tigress suspected to be killed by a brown bear, but which wasn´t eaten. Looks to be somewhat unclear case, but most of the fights between brown bears and tigers are known to end to dispersion. It of course doesn´t mean, that all indivduals would survive long after fight, even though not dying on spot. So that tigress could have got lethal injuries while fighting and then dying some time later. Or not.

If it would have died during fight, bear would have eaten it without a doubt, bears aren´t picky and eat what they kill of course. But some cases remain unclear and looks like that case remains as possible, but not sure.


This part was then again one, which I´m not sure what you meant:
Some male Ussuri bears, and non-hibernating bears ('Schatuns' or satellite bears) in particular, however, follow, and sometimes hunt tigresses with cubs and immature tigers. It has to be added, however, that no such incidents have been recorded in the period 1992-2020.”

When you write that no such incidents have been recorded in the period 1992-2020, you mean cases that bears would have hunted some tiger to kill it? And maybe non-hibernating bears following tigers in winter, which is rare too?

I ask because Asiatic black bears and brown bears both are known to follow tigers in order to have their share of tiger kills or usurping those kills. And this, as far as I know, happens all the time from spring to autumn more or less. Like that famous case with tigress Rachel which was practically persecuted by a brown bear to the point, that group of hunters were gathered in order to shoot the bear and help Rachel to keep her kills. I found that case a bit odd, that people were intervening, but of course brown bears aren´t endangered (yet) while tigers are and Rachel had that time cubs too. It s´naturally just one example. I mention this because, imo, that text could be understood in wrong way what comes to bears following tigers.

While that new book didn´t seem to bring in anything new to this tiger-bear topic, one interesting thing giving some new data are camera trap photos. Some already shared ones show tigers and bears captured to photos in same places, but looks like, that not too many of these photos are published yet. Hopefully in future more of these photos come out and more information about it which bears and how often there are etc.
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United Kingdom Sully Offline
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New study from Rajaji emphasising breeding females as a better measure for the success of tiger populations than a raw increase in numbers


Demographic and ecological correlates of a recovering tiger (Panthera tigris) population: Lessons learnt from 13-years of monitoring

Abstract:

Efforts are on to recover tiger populations range-wide, but we lack suitable metrics to characterise and evaluate such recoveries. Identifying such metrics requires an understanding of tiger population dynamics and its ecological correlates in either recovering populations or those exposed to anthropogenic influences. We monitored a recovering tiger population from 2004 to 2017 in Rajaji National Park, India. Using photographic data and spatial capture-recapture models in an inviolate site vacated by pastoralists (zone 1), we identified demographic parameters of a recovering population. By contrasting it with a site that is presently occupied by pastoralists (zone 3) and one that is isolated (zone 3), we identified conditions facilitating recovery. In zone 1, connected to a large source population in Corbett Tiger Reserve, density increased from 2.08 tigers/100 km2 to 7.07 tigers/100 km2 corresponding to an annual growth rate of 4.5%. Density also increased in zone 2 (2.6 tigers/100 km2 to 6.22 tigers/100 km2), but estimated apparent survival was 0.47 against 0.81 in zone 1. Recovery in zone 1 was accompanied by increased survival of females, while female tenure was shorter in zone 2. Due to the lack of functional connectivity, tigers in zone 3 are facing local extinction. Our results demonstrate that creating inviolate spaces to secure breeding populations and maintaining landscape-wide connectivity to expand breeding cores is critical for recovery. We highlight that relying solely on population increase may lead to unreliable inferences about population performance and instead suggest tracking survival and female land tenure to qualify recovery and success of conservation interventions.
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First tigress tranquilized, radio-collared for translocation to Rajaji Tiger Reserve

After years of waiting, the Uttarakhand forest department on Wednesday tranquilized the first tigress in the state in the Corbett landscape, for translocating it to the Rajaji Tiger Reserve.


JS Suhag, chief wildlife warden of Uttarakhand forest department said, “The first tigress in Uttarakhand was tranquilized in the buffer area of Corbett Tiger Reserve on Wednesday. The tigress will be shifted to Rajaji Tiger Reserve on Thursday as part of the project to increase the density of the big cat there.”

The project for translocation of tigers to the western part of Rajaji was approved by the central government in 2016.

Last September, a team from the National Tiger Conservation Authority (NTCA) visited Rajaji to conduct reconnaissance for the translocation exercise and had suggested a soft release of a pair of tigers in the reserve’s western side.

In a soft release, tigers are released in a large enclosed area where they are kept for a few days to check if the animals have any diseases before being completely released in the wild.

A total of five tigers, including two females, will be translocated to Rajaji Tiger Reserve. .
Rajaji Tiger Reserve at present has around 37 tigers with only two tigresses in its western part, which is spread over 570 sq km. The reserve has a carrying capacity of 83 tigers, revealed a recent survey conducted by the state forest department. The eastern and the western part of the reserve are divided by a busy traffic corridor making it difficult for the tigers to migrate between the two parts.

On Wednesday, director of Corbett wrote to the Garhwal Motor Owners Union Limited stating conditions ahead of starting a bus service between Pakhro-Morghatti-Kalagarh-Ramnagar.

Rahul, director of Corbett Tiger Reserve, who uses his first name, in the letter, wrote that this bus service will continue till further orders with only one-way traffic on any single day.

The conditions further state that buses will not run during heavy monsoon, fare will be charged only at Pakhro and Dhela gates, from the point of view of wildlife conservation two forest officers will be allowed to travel daily free of cost. The bus will not be allowed to ply before sunrise and after sunset.
During forest fire season, bus drivers will be held responsible if any passenger throws any combustible item outside the bus like match sticks and that bus staff will help the forest department by reporting about fire incidents. The bus will not stop anywhere while crossing the tiger reserve area and no one will be allowed to de-board. The conditions also state that wildlife will have the first right to cross roads and if they are hurt in the process then action will be taken under relevant sections of the Wildlife (Protection) Act.
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The influence of reproductive status on home range size and spatial dynamics of female Amur tigers

Abstract:

In populations of wild felids, social status is one of the most important factors shaping home range size and spacing patterns. For female Amur tigers (Panthera tigris altaica), we documented significant changes to the structure of home ranges and core areas during cub-rearing. We used VHF telemetry data collected over 18 years in Sikhote-Alin Biosphere Reserve, Russia, to assess the following: (1) home range and core area size and (2) spatial shifts with and without cubs and (3) spatial shifts associated with philopatry. Home range and core area sizes of females collapsed by 60% after birthing, with recovery requiring 18 months. We hypothesized that usurpation of temporarily abandoned territory by other females during cub-rearing was a possibility, but aside from philopatry, we did not observe a loss of territory or evidence of competition for space. Home range boundaries changed little during cub-rearing but shifting core areas revealed that females were using different segments of their home range while rearing cubs, contradicting the notion of a single, most important core area for breeding females. Our results support two hypotheses of space use by large carnivores: that adult breeding females achieve higher reproductive success by maintaining a home range just big enough to feed herself and her offspring, and a second hypothesis that females expand home range size when space is available to allocate land to daughters. We suggest that these hypotheses are not mutually exclusive, but explain patterns of space use by female felids under different demographic conditions.
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India will now be a home to 51 Tiger Reserves.


*This image is copyright of its original author



The centre has approved the
Tiger Reserve status for Srivilliputhur and Meghamalai sanctuaries in Tamil Nadu.

This will also be the Tamil Nadu's 5th
Tiger Reserve.

This new tiger reserve is spread over 1,016,57 sq km (core area – 641.86 sq km, buffer area – 374.70 sq km)  with the potential to provide much needed habitat for tigers dispersing from neighbouring Periyar Tiger Reserve & Anamalai Tiger Reserve.



*This image is copyright of its original author


Source: Ankit Kumar, IFS on Twitter: "India will now be a home to 51 Tiger Reserves.? The centre has approved the Tiger Reserve status for Srivilliputhur and Meghamalai sanctuaries in Tamil Nadu. This will also be the Tamil Nadu's 5th Tiger Reserve. [url]https://t.co/bDkHjYxEO8" / Twitter[/url]
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