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ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
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ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
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 (03-22-2020, 11:53 AM)peter Wrote: FEROCE Those postings are now deleted. I would add this much, we have own thread(s) for bear and tiger interactions. Even though these postings, which Peter mentioned were visible only for moderators, they had nothing new what comes to brown bears and Amur/Siberian tigers interactions. Interest for these two big predatory species co-existing is understandable, but old information has been posted here and there countless times and has frankly speaking nothing to offer for people who have had interest for that issue, at least what comes to aggressive confrontations. People who have interest can find older discussions from this thread and from threads which actually are meant for information about bear-tiger interactions. I would add also it, if someone one day come up with something new, published late 2019 or 2020, post by all means, but in right thread as @peter said it very clearly. This thread has a lot of quality information and the less pointless debates here, the better.   (03-22-2020, 01:16 PM)TigreFeroce9 Wrote: I am sorry @peter Good attitude. Appreciated. Apology accepted and advice to leave the forum withdrawn. However. The remarks on the Premier League stand. That section has quality information. If you want to post in a thread in the Premier League, make sure the info you have meets the threshold. Contact a mod before you post and follow his advice. A bit over the top? No. It isn't easy to find good information about wild animals on the internet. Misinformation is everywhere. Our aim is to provide good info only. Well over 15 million views in 6 years only says this policy is appreciated by many from all over the world. In order to get, and stay, there, moderation is of vital importance. My advice is to read. In that department, this forum has a lot to offer. When you want to interact, start in a different section. Contact our mods before you do. They're well-informed and always willing to assist. Good luck, Peter. 
Mitogenome analysis reveals a complex phylogeographic relationship within the wild tiger population of thailand
Abstract We present the first study of the complete mitogenome of wild tigers Panthera tigris in Thailand. Thailand has been recognised as one of the most important countries within the geographic range of P. tigris and is home to 2 subspecies: Indochinese P. t. corbetti in the north and Malayan P. t. jacksoni in the south. We obtained samples from wild tigers in a large forest complex in northern Thailand (Western Forest Complex, WEFCOM) and from locally confiscated individuals in southern Thailand close to the border with Malaysia. Our results support the occurrence of both Indochinese and Malayan tigers in Thailand and reveal complex phylogeographic patterns of the wild tiger population in Southeast Asia. https://www.researchgate.net/publication/299405331_Mitogenome_analysis_reveals_a_complex_phylogeographic_relationship_within_the_wild_tiger_population_of_Thailand PDF Link https://www.int-res.com/articles/esr2016/30/n030p125.pdf (04-04-2020, 10:10 AM)GuateGojira Wrote:(04-02-2020, 10:06 AM)strana Wrote: Guate, THE RELATION BETWEEN HEEL WIDTH AND WEIGHT IN WILD AMUR TIGERS - I Decent explanation on the problems distinguishing young adults (3-4 years of age) from adults (5 year and over), Guate. Most reports on young adult males I have suggest they range between 150-180 kg. If a table has young adults, chances are the average will be affected. a - Heel width range in wild male Amur tigers As to the weight of wild Amur tigers captured or photographed after 2005. In brown bears, heel width is a good indicator of weight. My guess is it isn't much different in big cats. In most male Amur tigers, the heel width ranges between 10,0-12,5 cm. Male tigers with that width, depending on age, range between 100-200 kg. b - Heel width in large male Amur tigers As far as I know, there're three reports about male Amur tigers with a heel width ranging between 13,0-14,0 cm. One of them is mentioned in 'Winter ecology of the Amur tiger' (A.G. Yudakov and I.G. Nikolaev, 2nd revised edition, Vladivostok, 2012, pp. 144). The two other reports are recent. The male below has a heel width of 13,5 cm. The photograph was first posted by Lycaon:  *This image is copyright of its original author c - The effect of growth on the relation between heel width and weight in wild Amur tigers There's, as I said before, no reliable table with information on the relation between heel width and weight in wild Amur tigers. I did, however, find this table. Although the scope is limited (it has information on 2 young adult males and two adult males only), it's something. The table also has information on the effect of growth in wild Amur tigers. It strongly suggests wild male Amur tigers continue to grow until they're 7-8 years of age:  *This image is copyright of its original author d - The relation between chest girth and weight in brown bears Below is a link to an interesting article on the relation between chest girth and weight (and zygomatic width and weight) in brown bears: https://www.bearbiology.org/wp-content/uploads/2017/10/Glenn_Vol_4.pdf I will add a bit more on brown bears in the next posts. 
@peter, thank you for sharing that table. It gives us a dataset to create a predictive regression equation.
I split the dataset into two. The first set of graphs does not use the same individual multiple times if multiple measurements were available. Rather, each individual is represented just once with greatest pad width (and the corresponding weight at that measurement).  *This image is copyright of its original author This next set of graphs utilized all measurements on that table such that if an individual is measured multiple times it is represented multiple times. This could be a reasonable approach as well as it still shows weight change with pad growth and is based on a greater sample size of measurements.  *This image is copyright of its original author When pooling together males and females, the fit is mediocre however there is a significant relationship. When we split the sexes, we note that males seem to have a very strong and significant association between pad size and mass in both models (R^2 >=0.9). On the other hand, females have a poor association. What could be the reasoning for such? Perhaps the females were not in equal shape between specimens, some emaciated while others not. It is also possible the measurements weren't done as precisely. Using all tigers and not allowing one individual to be represented multiple times temporally, a 13.5 cm pad would weigh 226 kg. Using all tigers but allowing an individual's multiple measurements to be included in the foundation, the estimate would be 221 kg. Using only males and not allowing one individual to be represented multiple times temporally, a 13.5 cm pad would weigh 283 kg. Using only males but allowing an individual's multiple measurements to be included in the foundation, the estimate would be 274 kg. The reader can decide which formula they like best. As stated before, the pooled equation has poor r^2 and thus likely a much weaker estimate compared to the only male equations. For the sake of completeness, I'll add in an isometry estimate. Using the largest pad sizes of the 5 males (average pad size 11.1 cm, average weight 152 kg), the isometric estimate of a 13.5 cm pad would be 275 kg. If we use all temporal measurements and allow specimens to be represented multiple times (average pad size 10.5 cm, average weight 137 kg), the isometric estimate is 291 kg.
ALL
This post has answers to a number of questions in PM's I got in the last months. a - Posting frequency a1 - Over the years, I collected a lot of information. Although I knew what was where, the significant increase in the department of information often resulted in problems. In the end, I had no option but to decide for a reorganisation. I'm not quite there yet, but I'm close. It took me more than a year. a2 - Most of you know I'm not involved in 'copy and paste'. Writing a post in your own words takes time. Not seldom, a post written in this way has to be reread and edited a number of times. Also remember that preparing a series on a specific item takes quite a bit of time. a3 - I've been interested in big cats in general and tigers in particular for a long time. Not long after I started posting, I was contacted by people interested in big cats in some way. Answering questions takes time. As most of those with questions are (semi-)professionals, I decided to answer them in a professional way. Meaning it developed into a kind of business. The forum I started with Sanjay will profit as well. What I'm saying is my time is limited. I like posting a lot, but I'll have to take a break every now and then. b - Books There are many ways to get to good information about wild big cats. Reading is one of them. I try to read as many recent publications as possible, but also like old books a lot. Naturalists, forest officers and hunters do not quite compare to field biologists working in Sumatra, Malaysia, Thailand, Burma, Nepal, India, China and Russia today, but in a way it's quite close. The reason is they too spent many years in wild country. A century ago, many of them saw things we can hardly imagine. Yet they happened every now and then. Quite a few biologists, equipped with tools like collars, have expressed doubts about observations of hunters, but it's quite possible big cats behaved in a different way when the human population hadn't yet exploded. All big cats are thinking animals able to adapt their behaviour over time. Also remember that individuals that didn't adapt (referring to man-eaters and cattle-hunters) were taken out most of the time. It no doubt had an effect. Anyhow. In this thread, I will discuss as many modern publications as possible. Every now and then, however, a book written a long time ago will feature. A friend recently found 'Big Game Hunting in Manchuria' (English translation, 1936). It will be discussed in a few weeks. c - The relation between 'heel width' and weight in wild Amur tigers There is a discussion about the size (weight) of wild Amur tigers in another thread. As the discussion could be of interest of readers interested in tigers, I proposed to continue in this thread. Wild Amur tigers are still captured, measured and weighed every now and then, but not as often as 10-20 years ago. I haven't seen recent publications with information on the size of wild Amur tigers. Those interested in tigers only have a few videos and photographs. Some photographs show large individuals, but we have no clue as to what 'large' is. There are different ways to get to guesstimates. Bear biologists concluded there's a strong relation between skull width and weight (a), and chest girth and weight (b) in brown bears. Heel width, also known as 'pad size', also is a good indicator of weight in brown bears ©. My guess is it isn't very different in tigers. For this reason, my proposal is to post information about the relation between 'heel width' and weight in wild Amur tigers. If we have enough, Tigerluver, who moved a number of posts to this thread, will be able to get to an equation. d - One more thing The extinction threads were moved to this section for a reason. The aim of these threads is good information. All members can post, but remember moderation is more strict than in the other sections. If you've questions, contact a mod.
THE RELATION BETWEEN HEEL WIDTH AND WEIGHT IN WILD MALE AMUR TIGERS - II (continuation of I)
e - Heel width and weight in wild Amur tigers found dead in the period 1970-1994 Our supermod @tigerluver recently posted the results of a number of computations based on the table in my first post in this series. He concluded that an adult male Amur tiger with a heel width of 13,5 cm. most probably ranges somewhere between 221-291 kg. That 'somewhere' is affected by a number of (largely unknown) factors. Health no doubt is one of them. The table in my first post of this series is based on healthy wild Amur tigers. The conditions in the Russian Far East, however, are far from easy. Not a few tigers struggle with the conditions. I'm not only referring to cubs and old tigers. Young adults also often seem to need quite some time to adapt. Although the conditions in the Russian Far East have improved in the last decades, quite many tigers still perish well before their time. Poaching is a factor, but there are more. In 1993, Igor G. Nikolaev and Victor G. Yudin published 'Conflicts between man and tiger in the Russian Far East'. An English translation was published a few years later. Although the publication is interesting all the way, it is about the tables in this post. The reason is they have information about the relation between heel width ('front paw pad width') and weight in tigers found dead in the period 1970-1994. I can hear you say 1970-1994 in a document first published in Russian in 1993? Yes. On top of that, in the abstract, Nikolaev and Yudin say the data were collected in Primorye in the period 1970-1996. A bit confusing, I admit, but my guess is the explanation is not that difficult. Most data were collected in the period 1970-1992. These were used for the document published in Russian in 1993. The English translation, published a few years later, has one extra incident. It could have been the only incident in the period 1994-1996. The tables no doubt have an effect on the equations referred to above, because quite a few tigers in the table were in bad shape before they perished. This, most probably, is the reason some of them entered sheds and attacked domestic animals (including dogs) in the first place. Most males were wounded and/or killed by humans, but others perished in conflicts with other animals. One male was killed by a male tiger, another was killed by a bear and a third male was killed by a wild boar. A fourth male almost lost his paw in a fight with a bear and two others were wounded by a wild boar and, most probably, a bear. One male drowned in a river after he had been severely injured by a horse. The tables, apart from 1 male and 1 female killed in Khasansky District in 1987, do not include tigers killed by poachers in the winters 1991-1992 and 1992-1993. In these 2 winters, nearly 70 Amur tigers were killed by poachers (...). Here's a scan of the abstract:  *This image is copyright of its original author Here are the scans of the 3 tables (38 males, 18 females and 6 cubs). The 'heel width' of male tigers ranged between 9,5-12,0 cm. Young adult males ranged between 9,5-12,0 cm, whereas adult males, most probably, ranged between 10,5 and 12,0 cm. In females, the range was 8,5-10,0 cm. The heaviest male was 192 kg. This, otherwise healthy, male (discussed in this thread some years ago) wasn't able to move properly as a result of a disease. His heel width was 11,5 cm. Another male was 185 kg. (heel width 11,6 cm). The heaviest young adult male was 180 kg. (heel width 10,0 cm.). Another was 175 kg. (heel width 12,0 cm.) and in excellent condition when he perished. Two other young adults were 149 kg. (heel width 10,5 cm.) and 150 kg. (heel width 10,5 cm.). Three 3-year old males were shot after they had attacked domestic animals (and a man). They were 125 kg. (heel width 10,5 cm.), 130 kg. (heel width 10,3 cm.) and 135 kg. (heel width 9,7 cm.). The last male was shot in a dynamite-store (...). There are no details about the tiger killed by a bear in Progranichny in 1972, but the tiger killed by a wild boar was 136 kg. (heel width 12,0 cm.). The male tiger wounded by a bear in 1981 was 168 kg. (heel width 11,8 cm.). Another male with a similar injury was 165 kg. (heel width 10,5 cm.). Both males were adult and, judging from the relative fat index, in reasonable shape. The heaviest adult female was 130 kg. (heel width 9,5 cm.). She was killed by poachers in 1987. Two adult tigresses shot in 1985 suffered from blisters. It must have affected them: in weight, they were well below par. In 1986, an oldish tigress died from starvation in Ussurisk. She was 65 kg. only (heel width 9,0 cm.):  *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
(04-06-2020, 09:38 AM)tigerluver Wrote: Excellent as always @peter. Before I churn out a new formula, are the specimens from Nikolaev and Yudin different from the dataset in the prior table. Also, what are sources of the first table? Many thanks for your knowledge. The Nikolaev and Yudin tigers perished in the period 1970-1994. The tigers featuring in the first table I posted were captured after the WCS-table had been published in 2005. This means the Nikolaev and Yudin tigers are different from the tigers in the first table I posted. You can use them, that is. I've been trying to find the source of the first table, but came up empty. The reason is I lost quite a bit of information when I changed to Windows-10 a few months ago. A great pity, but these things happen. This, by the way, is the reason I often print documents and tables. I remember the table was printed in the period I was a member of the former AVA forum. I joined AVA in the fall of 2009 and left in February or March 2014. I was most active in the period 2010-2012. If I was asked to be more specific, I'd say I found the table not long after I joined. This means the table is from a document published in the period 2006-2012. In order to find the source of the table, I intend to visit the former AVA forum (now Tapatalk) soon. My guess is the table is in a thread about (the size of) Amur tigers. I know it's not much, but it's the best I can do right now. I have more information on the relation between 'heel width' and weight in Amur tigers. I'll post it tomorrow. 
Pugmarks are a great tool to estimate size but you should make sure to note time of year since its mentioned by a few that obviously in the snow or mud a pugmark can be enlarged while in dry dirt it's generally true to form.
But from everything I've read, the heavier the the cat the deeper and larger the pug mark.
THE RELATION BETWEEN HEEL WIDTH AND WEIGHT IN WILD MALE AMUR TIGERS - III (continuation of II)
f - Heel width and weight of 'Banzai' In 2011, 'With love, from the Amur tiger' (M. Dupuis) was published by Tendua (Association for Biodiversity Conservation). The story of Myriam Dupuis was discussed in different forums, because it has detailed information about a young adult male Amur tiger captured in a foot snare in the Ussurisk Reserve in Primorye (Russia) on May 21, 2011. Dupuis took a number of photographs. This post has scans of 3 photographs. This one was taken just before or after the male tiger called 'Banzai' had been darted:  *This image is copyright of its original author This photograph shows 'Banzai' had long and sharp canines. The incisors show little wear as well, meaning he was a young adult male when he was captured and measured. According to Dupuis, the staff also thought he was quite young: " ... According to the deputy director, the animal should weigh about 150 kg, probably a young individual ... " ('With Love, from the Amur tiger', pp. 7 of 13)  *This image is copyright of its original author After he had been measured, 'Banzai' was weighed:  *This image is copyright of its original author The tiger was measured 'over curves'. The measurements show 'Banzai' still had some growing to do. The same was true for another young adult male captured in Ussurisk ('Luke'). In spite of that, both 'Banzai' (207 kg.) and 'Luke' (212 kg. ) were heavy. In fact, they still are the heaviest wild male Amur tigers actually weighed. Tiger 'Luke' was weighed in winter, meaning he could have been a bit heavier than in spring or summer (most Amur tigers seem to thrive in winter), but 'Banzai' was weighed in May. The photographs show he was in good condition, almost lanky, when he was captured. In order to prevent posting more scans of the story, I decided for a table with the vital statistics of 'Banzai'. It is an original for Wildfact:  *This image is copyright of its original author All measurements are in cm. The weight is in kg. One more remark to finish the post. In her story, Dupuis says the " ... width of the front leg ... " (pp. 9 of 13) was 11,5 cm. My guess is she referred to the width of the heel of the front paw. Her story has a photograph showing the width of the pad of the hindleg was measured. It's remarkable, by the way, that both young adult males were heavier than all other males actually weighed in Russia. This although both, most probably as a result of their age, were about 4-5 inches shorter in head and body length than the males in WCS-table published in 2005. The question, again, is if the table is representative. The scale showed 'Banzai' was 213 kg. Without the tarp, the strings and the collar, 207 kg. remained.
With all the data @peter kindly shared, a new, rather robust equation can be calculated. I counted specimens of all ages except those marked as starving. The sample size of 48 was statistically powerful and excellent given the limitations in recording measurements of the subject matter.
 *This image is copyright of its original author Applying the computed formula, a 13.5 cm wide paw would weigh 295 kg. The 95% confidence interval would be between 259 kg and 337 kg, inclusive. In other words, the dataset indicates that there is a 95% chance the owner of a 13.5 cm wide paw weighs 259-337 kg, with the most likely weight closer to 295 kg.
THE RELATION BETWEEN HEEL WIDTH AND WEIGHT IN WILD MALE AMUR TIGERS IV (continuation of III)
g - Heel width of Amur tigers captured in the Sichote-Alin Biosphere Reserve 1992-2004 g1 - Two tables with information about the heel width and weight of male Amur tigers In 2005, 'Tigers in the Sichote-Alin Zapovednik: Ecology and Conservation' (Miquelle et al.) was published (in Russian only). The title of chapter 7 is 'Morphological Indicators of the Amur tiger' (Kerley et al.). It has a number of tables. Most of these were posted in AVA about a decade ago. The table below is from Chapter 7. It was used for this post, because it has information about the heel width of the tigers captured in the Sichote-Alin Zapovednik:  *This image is copyright of its original author The table has no weights, but my guess is the tigers used for the table are the same as those featuring in another table and that table has specific information about all individuals captured in the Sichote-Alin Zapovednik in the period 1992-2004:  *This image is copyright of its original author Table 7.3 is based on 12 male tigers, whereas the other table is based on 11 males. It's very likely that the 11 males in the last table were also used for Table 7.3. This means both tables can be used to get to get to conclusions on the relation between heel width and weight in the 11 male tigers used in both tables. Before starting on the conclusions, we need to know a bit more on the 11 tigers in the second table. g2 - Information about the 11 male tigers used in both tables From the top down: ♂ 01 - no details available ♂ 02 - weighed 3 times (range 170,1-201,8 kg.) ♂ 03 - young adult (assumption) ♂ 04 - no details available ♂ 05 - longest measured ♂ 06 - no details available ♂ 07 - young adult (assumption) ♂ 08 - no details available ♂ 09 - euthanized ♂ 10 - released from rehabilitation ♂ 11 - young adult (assumption) g3 - Averages 1 - The 11 male tigers averaged 169,45 kg. (range 125-200) 2 - Without the euthanized 125 kg. tiger, the average of the remaining 10 male tigers is 173,9 kg. (range 146-200) 2 - The 3 young adults (without the euthanized 125 kg. tiger) averaged 149,33 kg. (range 146-155) 3 - The 7 adult tigers (without the euthanized 125 kg. tiger) averaged 184,43 kg. (range 170-200) g4 - Conclusions 1 - The average heel width of 11 male tigers captured in the period 1992-2004 was 11,4 cm. (range 10,5-12,8) 2 - The average weight of these 11 tigers was 169,45 kg. (range 125-200) 3 - The 11 male tigers captured in the Sichote-Alin Zapovednik in the period 1992-2004 averaged 169,45 kg. and 11,4 cm. in heel width h - The relation between heel width and weight in male brown bears in northeastern Siberia The table below, posted by 'Warsaw' in AVA quite some time ago, was added for comparison. When I changed from Windows-7 to Windows-10 some months ago, vital information was lost. I'll try to find tre source of the table when I have time:  *This image is copyright of its original author
(04-08-2020, 12:49 AM)tigerluver Wrote: With all the data @peter kindly shared, a new, rather robust equation can be calculated. I counted specimens of all ages except those marked as starving. The sample size of 48 was statistically powerful and excellent given the limitations in recording measurements of the subject matter. Super effort, Tigerluver. I admit I have some doubts on the predicted weight of a male with a heel width of 13,5 cm., but the table on the relation between heel width ('palm width') and weight in brown bears in northeastern Siberia, on the other hand, strongly suggests a relatively small increase in heel width over an, unknown, threshold can result in a very substantial increase in weight. Another factor that resulted in doubt regarding the outcome of the prediction is recent information about the size of wild Amur tigers. The data collected in the last 28 years suggest adult male Amur tigers, depending on the season and the conditions, range between 170-212 kg. Although nothing can be excluded, there's no information of males exceeding 500 pounds (226,8 kg.), let alone, as the equasion predicts, 700 pounds (317,52 kg.). Some captive male Amur tigers, on the other hand, have approached or even exceeded 650 pounds (294,84 kg.). As far as I know, all of them were Studbook tigers, meaning they're related to wild Amur tigers caught in the fifties, sixties and seventies of the previous century. Apparently, the genes to get to a large size are still there. The question is if large males can be captured with an Aldrich footsnare. After reading 'The snare for tiger' (S. Kolchin and P. Maystrenko, 2013), I doubt if the Aldrich snare would be strong enough to restrict even an average-sized male. According to Kolchin and Maystrenko, Ivan Seryodkin was injured by a big male tiger who broke the snare binding when he was approached by people on June 17, 2008. Other male tigers were quite badly wounded while trying to escape. I don't know if conclusions were drawn after these incidents, but my impression is less tigers have been captured in the last decade. If there are tigers exceeding 700 pounds today, as the equation predicts, chances are they will not be captured. Not with a footsnare. The only, indirect, way to test the equasion, therefore, is to go over the historic records once again. In Chapter 6 (Appendix 6.1) of 'Tigers in Sichote-Alin Zapovednik: Ecology and Conservation', 2005, 44 records were reviewed. Most of them were unreliable. Baikov is well represented in Appendix 6.1: he shot 14 of the 44 tigers that made it to the Appendix. Of these 14 records, 11 were considered as unreliable, whereas two were considered as 'highly reliable'. The reason these 2 were considered as highly reliable is Baikov provided the necessary details. That, however, doesn't mean that the tigers of 320, 325 (twice) and 390 kg. he shot were a result of imagination, hearsay or inaccurate scales. The historical records, if anything, suggest the predicted weight of a tiger with a heel width of 13,5 cm. (259-337 kg.) could be close. We'll never know how close, but tigers in the predicted range have been shot in the recent past. And what about tigers the 3 tigers exceeding 340 kg. in Appendix 6.1? A century ago, more tigers had more room and more chances to live to old age. In large regions with good conditions and few people like Manchuria, some tigers might have reached a great size. I've seen direct descendents of tigers caught close to Manchuria in zoos in western Europe in the late sixties and seventies of the previous century. Compared to captive Amur tigers today, they were not longer, but often a bit taller and nearly always more robust. Bigger limbs, bigger necks and limbs and, in particular, bigger skulls. I thought they were from a different world:  *This image is copyright of its original author Some males photographed in the last 2 decades seem to be quite close. More protection and better conditions have an effect:  *This image is copyright of its original author  *This image is copyright of its original author Thanks again for the equation. Good work. Maybe you can find time to go over the bear information. |
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