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

Apex Titan Offline
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( This post was last modified: 12-01-2021, 11:27 PM by Apex Titan )

(11-30-2021, 08:54 AM)peter Wrote: APEX

Interesting, balanced and well-written post. Agreed with all points made. 

It is a fact details about bears killed by tigers are often lacking. One could, as some prefer, conclude there's no solid proof adult male brown bears have been killed by Amur tigers and, for this reason, maintain they are out of the predatory reach of even large male Amur tigers, but there's way too much quite reliable information pointing in a different direction. 

I'm not only referring to the, admittedly inconclusive, information in, for example, 'Die Säugetiere der Sowjetunion' (V.G. Heptner and A.A. Sludskij, 1980) and 'Der Tiger' (V. Mazak, 1983), but to quite a few recent publications, books and articles. That's still without the interviews you mentioned. I'm referring to interviews with specialists (most of them biologists) loaded with knowledge and experience. 

The incidents in Mazak's book, by the way, are not based on unverified stories and hearsay, but on unpublished notes of an unknown Russian biologist (K.G. Abramov) and a letter (dated May 8, 1970) of an experienced Russian hunter (V. Jankowski). He saw both the tiger and the remains of the big male bear he killed a few days before he was shot.  

Tiger 'Ochkarik' 

Members of forums interested in tigers and bears in the Russian Far East often refer to the size of adult male Amur tigers and adult male Ussuri brown bears. Most of them, for reasons discussed in my previous post, think it would take quite a tiger to kill an adult male brown bear, but reliable information (referring to recent newspaper reports, articles, scientific publication and books) suggests this is not the case. 

Let's take the tiger A. Batalov knows quite well as an exaple. Tiger 'Ochkarik' was never weighed, but Batalov has weighed quite a few bears. If he says 'Ochkarik' ranges between 160-180 kg, we have to assume he's quite close. In at least two interviews, Batalov said this male tiger killed and completely ate the very large bear that tormented tigress 'Rochelle' for quite some time. This bear, called 'Chlamyda' on account of his size, was estimated at 350-400 kg, if not more. 

Although Batalov, as far as I know, didn't respond to the questions of our member 'Nyers', we can't be sure 'Ochkarik' really killed 'Chlamyda'. It is, however, lear the bear he killed was a large one. So large, Batalov hardly recognized 'Ochkarik' after he had eaten the bear. Does this prove an adult male Amur tiger is able to kill a larger (heavier) male brown bear? No. The reason? No hard evidence and no details.   

Tiger 'Borya' 

There's another male tiger that made headlines. I'm referring to male tiger 'Borya' ('Boris'). When he was about 18 months of age, it was President Vladimir Putin himself who released him into the taiga in May 2014. In the reserve located in the Jewish Autonomous Region, 'Borya' didn't need a lot of time to adapt. The youngster killed at least two bear in his first year. Biologist were unable to get to an accurate determination, but they thought both bears, like 'Borya', were youngsters (2-3 years of age). 

The difference between 'Ochkarik' and 'Borya' is the last one was wearing a collar transmitting signals for about two years. This enabled biologists to track him and find some of the animals he killed. What they found, proved immature male Amur tigers, in contrast to what was assumed for a long time, hunt young bears.  

It also proved young tigers can quickly develop in this department. In an article published June 10, 2015, it's stated 'Borya' had killed at least one adult brown bear. Our member 'Apex Titan' posted the article in another forum some time ago. 

Here's a scan of the article published by VladNews and written by Nikolay Kutenkikh. It's interesting from start to finish:


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author
   

About 18 months later, another article about 'Borya' was published. It, without a shadow of doubt, proves 'Borya' still hunted adult bears. It also proves adult Amur tigers occasionallky hunt together. I scanned the first and third page of the article:


*This image is copyright of its original author


*This image is copyright of its original author


Conclusion 

Although there's no reliable evidence of adult male brown bears killed by male tigers in the period 1992-2021, reliable information suggests otherwise. I'm not only referring to books published before the Siberian Tiger Project started, but also to recent information and interviews with those considered to be in the know. Although they in particular favour the male tiger for reasons discussed in my previous post, it's also likely adult male tigers have been killed by male brown bears. 

What is known (referring to books written by Russian biologists published before the Siberian Tiger Project started in particular), suggests individuals affected by disease, injuries, starvation, age and a lack of experience were the most common victims.

Another possibility (which is more likely) is that 'Borya' hunted and killed adult bears and then shared his kills with the tigress 'Svetlana'. No one knows for sure if they hunted bears together, as no one witnessed these events, specialists only found the kill-sites. Male tigers are well known to also share their kills with their mates (tigress) and cubs. Here's a good example...

Tigress and cubs feeding on a large boar that was killed by a male tiger:

"For the first time, camera traps recorded her together with her sister and mother in 2018. Below is a video in which the whole family feasts on a wild boar killed by an adult tiger, which experts consider the father of the family."

"The boar, apparently, was large: a female with tigresses (cubs) came to the carcass 3 times in the period from February to April 2018."











Male tiger took away the remains:







http://amur-tiger.ru/ru/press_center/news/1479/


This kill lasted for a long time, with several tigers feeding on the boar, which indicates that the male tiger must have killed a very large male wild boar.

Also, I forgot to mention, that Kucherenko's colleague eye-witnessed a case of a tigress that stalked and killed a big male brown bear. The Russian hunter, Andrey Efremovich has no reason to make this story up, considering the fact that he really hated and greatly feared tigers. Here's what he tells Kucherenko in their conversation:

"However, everyone agrees that tigers crush many times more than hunters of all categories ... But the main reason for my dislike for the tiger lies elsewhere. He's scarier than a bear. He has an irresistible mental influence on a person. Compare this: you heard the roar of an invisible bear. So what? He stopped, thought and walked on. And the tiger's roar? Heart to throat rises and knees tremble."...  

https://www.litmir.me/br/?b=170047&p=34
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Matias Offline
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Why there isn't enough being done to save the Malayan tiger.
MUNA NOOR
SATURDAY 31 JULY 2021
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Numerous threats are faced by those attempting to save the Malayan tiger, including governmental and environmental challenges. Photo: WWF Malaysia

*This article was first published on July 29th, 2020.

Compare Malaysia’s progress with that of Russia, India and Nepal. 


In 2018, figures recorded in India showed that Royal Bengal tigers have doubled in number from 2016’s 1,411 to 2,967. In Nepal, numbers have risen from a baseline of 121 tigers in 2009 to 235 in 2018, an impressive achievement in a country barely recovered from a decade-long civil war.

 
And in Russia, where an estimated population of 40 Amur tigers were clinging to survival in the 1940s, these big cats have been brought back from the brink, with 433 individuals recorded in 2015. Strong leadership and unwavering government support for wildlife conservation have been cited as instrumental to the progress in those countries. It’s something Malaysia desperately needs. “Fundamentally, the political will was not there in both the Federal and state governments,” said Kanitha Krishnasamy, Director for Traffic in Southeast Asia and MYCAT Working Group member, when commenting on Malaysia’s failure. 


Since 2013, WWF-Malaysia and Traffic Southeast Asia have called for greater leadership and appealed for Malaysia’s Prime Minister to set up and chair a “Tiger Task Force”. The Tiger Task Force is based on India’s National Tiger Conservation Authority (NTCA), which was set up by India’s Prime Minister in 2005 and is chaired by the Minister of Environment and Forests. 


The NTCA is granted statutory and administrative powers which allow it, amongst other things, to relocate entire villages and compensate their residents, in order to create buffer zones to provide tigers a safe haven and reduce human-tiger conflict. 


In Malaysia, a similarly organised central coordinating structure with the ability to make executive decisions on policy, would allow issues of jurisdiction to fall away, foster inter-agency collaboration and facilitate the allocation of resources that long-term tiger conservation requires. 


Link: HERE
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Netherlands peter Offline
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( This post was last modified: 12-09-2021, 06:20 AM by peter )

ON THE SIZE OF CAPTIVE AMUR TIGERS - I 

I.1 - Introduction

About a year and a half ago, using articles and books published in 1974, 1993, 1996, 2003, 2005, 2011 and 2019, I did a series on the size of wild Amur tigers and Ussuri brown bears. 

In post 2,466, the relation between heel width and weight in both tigers and brown bears was discussed. Post 2,469 has information about the relation between heel width and weight in tigers. Post 2,472 has information about the vital statistics of male tiger 'Banzai', whereas the table published in 2005 (about the length and weight of 11 male Amur tigers) was discussed in post 2,475. Post 2,491 has more information about the relation between heel width and weight and tigers and post 2,511 has information about the total length and weight of male Amur tigers and male and female brown bears. 

The conclusion (see post 2,511) was adult (4 years and older) male Amur tigers averaged 184-185 kg and 298-299 cm in total length (measured 'over curves'), whereas adult (8 years and older) male brown bears, although about 15-20 cm shorter in head and body length (measured in a straight line), averaged 257,5 kg. Compared to adult male tigers, male Ussuri bears were shorter, taller and significantly heavier. 

The problem is the lack of recent, reliable, information about the size of adult wild male Amur tigers. This is the main reason I decided to discuss the relation between heel width and weight in most of the posts mentioned above. If you conclude it was an indirect way to find out a bit more about the size of wild Amur tigers today, you would be close. 

There is another, indirect, way to find more information about the size of wild Amur tigers. I'm referring to the weight and dimensions of their captive relatives. The condition is good data. The problem, as you guessed, is there's not too much known about the size of captive Amur tigers. Those interested in big cats often say captive Amur tigers are the largest big cats, but I never saw a table based on reliable information.

In order to get to an answer, I decided to do it myself. I started about half a year ago. A week ago, I concluded I had enough to get to a few tables. With 'enough', I mean I found decent (read quite reliable) information about the weights of 27 Amur tigresses and 61 male Amur tigers. Not bad, but I was hoping for a bit more. Information about the size of captive Amur tigresses in particular is few and far between.  

Information about the actual standing height at the shoulder, however, was even more difficult to find. Same for skull measurements and total length (measured 'between pegs'). 

I.2 - Sources

How reliable are the tables that will be posted? This question, unfortunately, is difficult to answer. I do not doubt the information found in scientific publications, but I'm not too sure about the information found in newspaper articles. For this reason, I tried to find as much as possible about individuals mentioned in these articles. In the 'List of references', you'll notice the space between different sources. When there's no space between two sources, it means they belong together (meaning both have information about the same tiger or tigress). 

Apart from scientific publications and newspaper reports, I used a few videos and information found in a few threads of our forum. I'm referring to the threads 'Captive lion and tiger weights' and 'On the edge of extinction - A - The tiger (Panthera tigris)'. Every post that has information about the size of captive Amur tigers was checked and again. All posts used for the table were considered reliable. With 'reliable', I mean as reliable as it gets. For a forum, that is.       

The most informative and reliable source still is 'Der Tiger'. This great book (referring to the third edition published in 1983) written by V. Mazak is one of the very few that has good information about the size (referring to total length measured 'between pegs', standing height at the shoulder and skull measurements) of captive Amur tigers. V. Mazak also wrote 'Notes on Siberian long-haired tiger, Panthera tigris altaica (Temminck, 1844), with a remark on Temminck's mammal volume of the 'Fauna Japonica' (in: Mammalia, 31 (4), pp. 537-573, 1967). This publication has reliable information about the skull size of wild Amur tigers.

In the period 2005-2021, however, interesting studies about the size of Amur tigers living in Chinese facilities and safari parks have been published. I'm referring to 'Study on growth and development of Amur tigers raising dispersedly', Weilin (S), Dissertation for the degree of Master, Northeast Forestry University, 2005 and 'Body measurement parameters and body weight of sub-adult and adult Amur tigers (Panthera tigris altaica)', Cui (Y) et al., Chinese Journal of Wildlife 2021, 42 (4), pp. 965-972 in particular, but there are more publications that are of interest.    

The tables (referring to the tables I'll post in a few days) also have information about a few Amur tigers in Japanese zoos. The reason is our member 'Betty' found and sent me the publications needed. Same for the Chinese publications I referred to in the previous paragraph and all reports published in Japanese and Chinese newspapers (referring to information used for the table). I also got an interesting article 'Betty' found on a (Korean) blog about a quite famous tiger living in the Seoul Zoo in the sixties of the previous century. I'll post the article after I posted the tables. 

If I was to conclude I would still have been struggling without the help of 'Betty', I would be very close. Many thanks, Betty!  

I.3 - Posting sequence

I'll start the series with the Chinese publications discussed in I.2. The reason is you won't find both studies in the list of references. A bit strange perhaps, but I didn't use the studies for the tables. The reason is they don't have nformation about individual tigers. Before posting scans of the tables in both studies, I'll add a number of remarks. All of them are based on information I got from 'Betty'. 

I'll also discuss a table about the size of captive Amur tigers posted by our member 'Kingtheropod' some years ago. I used some of the sources he found as well.

After posting both tables, I'll post the list of references, additional remarks and a few conclusions. 

In between, I assume our member 'Khan85' will post recent information about the size of wild Amur tigers he got from a researcher working in Russia. This information can be compared with information published in 2005 ('Tiger in Sichote-Alin Zapovednik: Ecology and conservation', Miquelle et al., 2005, in Russian) and discussed more than once in this thread (referring to the table that included 4 young adult males).

I.4 - A series about the size of captive Amur tigers in a thread dedicated to wild Amur tigers?

Yes. The first reason was explained in I.1. The second is there could be a relationship between the size of captive Amur tigers and their wild relatives. Using information about the size of captive Amur tigers, we could get to a hypothesis about the size of their wild relatives. 

This assumption is based on reliable information about the size of captive and wild Indian tigers (Panthera tigris tigris) in particular. Adult male Indian tigers (referring to 3 decent samples) in captivity average 185-190 kg (409-420 pounds), whereas as their wild relatives seem to be significantly heavier (210-215 kg or 464-475 pounds). In some regions, adult males (referring to averages only) could exceed that mark.  

The reason wild tigers often are heavier than their captive relatives is tigers are big game specialists. All adult males are individuals that survived the challenges they met in the period in which they became independent and established a territory. In that period of time (between 2-5 years of age roughly), they also survived encounters with competitors and, in particular, the animals they hunt. This means they are true (able) survivors. This is not true for their captive relatives. Those who had the opportunity to observe wild and captive tigers agreed captive tigers are mere shadows of their wild relatives. 

Although it hasn't been confirmed in studies, hunters in British India agreed male tigers in particular continued to develop after reaching adulthood. The largest individuals shot in the period 1860-1960 often exceeded 10 years of age. This development seems to be less pronounced in captive tigers. Captive male Amur tigers (referring to the Chinese studies mentioned in I.2) often quickly lose size (referring to total length and weight in particular) after reaching 7-8 years of age. Captive Amur tigers (males and females) also have significantly narrower 'heels' (referring to the heel width of the front paws).
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India Khan85 Offline
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( This post was last modified: 12-08-2021, 08:20 PM by Khan85 )

Hello guys

The information about wild amur tigers was shared to me by a researcher of modern and extinct animals. 

These are his exact words - 


¨...Amur tigers from my sample average 223 kg (n = 17).¨


¨...50% of the data comes from captive individuals while the other half comes from wild specimens, as far as I can recall to you (I am not allowed to share much of the data freely). The wild specimens averaged around 206 kg, with the largest being larger than the largest amur tiger recorded in literature (212 kg). I would have to check my database to see the precise value this specimen weighed in excess off.¨




Hope this helps!
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Netherlands peter Offline
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( This post was last modified: 12-09-2021, 09:28 AM by peter )

KHAN

Thanks for the information. Much appreciated. My advice is to keep silent about your source. This in order to prevent a barrage of questions from countless members and visitors. 

This post, to avoid confusion, has two paragraphs and a few questions.

1 - Amur tigers

When you contact your source again, tell him there's reliable information (large samples) about the total length of captive male Amur tigers. What is known (referring to the recent Chinese studies mentioned in my previous post), suggests they habitually approach or even exceed 10 feet in total length measured 'between pegs'. Biologists today seem to measure their wild relatives 'over curves'. In spite of that, only few males seem to get close to that mark. 

The first question is if biologists really measure wild Amur tigers 'over curves' today. The second is why the difference in length between captive and wild Amur tigers (about 8 inches measured 'between pegs') is that pronounced. 

Recent photographs (referring to cameratrap pics) suggest Amur tigers today show more individual variation than, say, two decades ago. They also seem a bit more bulky. Is this a result of selection (referring to the photographs published) or do biologists agree? 

We're also interested in the way male tigers and male brown bears interact. Although there's no confirmed evidence of a clash between males of both species in the period 1992-2021, Aramilev, the CEO of the Amur Tiger Project, suggests not everything was documented. Some of us think his ideas are based on real incidents, but others think adult males of both species avoid each other. What is his opinion?  

Ask your source if there's anything else of interest. Something ignored by many.

2 - Indian tigers

I recently read one of your posts in the thread 'Amur Tigers'. You wrote you had contacted a biologist working in India. He told you a number of adult male tigers had been darted in central India. The tigers were actually measured and weighed. One of them, not gorged and not empty, was 285 kg. Is this true? Any other details known about this tiger?

Would he be able to inform us about the dimensions (and weights) of an average adult male in central India? Is he able to compare tigers in central India with those living in other regions?
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( This post was last modified: 12-10-2021, 05:02 AM by Khan85 )

(12-09-2021, 09:27 AM)peter Wrote: KHAN

Thanks for the information. Much appreciated. My advice is to keep silent about your source. This in order to prevent a barrage of questions from countless members and visitors. 

This post, to avoid confusion, has two paragraphs and a few questions.

1 - Amur tigers

When you contact your source again, tell him there's reliable information (large samples) about the total length of captive male Amur tigers. What is known (referring to the recent Chinese studies mentioned in my previous post), suggests they habitually approach or even exceed 10 feet in total length measured 'between pegs'. Biologists today seem to measure their wild relatives 'over curves'. In spite of that, only few males seem to get close to that mark. 

The first question is if biologists really measure wild Amur tigers 'over curves' today. The second is why the difference in length between captive and wild Amur tigers (about 8 inches measured 'between pegs') is that pronounced. 

Recent photographs (referring to cameratrap pics) suggest Amur tigers today show more individual variation than, say, two decades ago. They also seem a bit more bulky. Is this a result of selection (referring to the photographs published) or do biologists agree? 

We're also interested in the way male tigers and male brown bears interact. Although there's no confirmed evidence of a clash between males of both species in the period 1992-2021, Aramilev, the CEO of the Amur Tiger Project, suggests not everything was documented. Some of us think his ideas are based on real incidents, but others think adult males of both species avoid each other. What is his opinion?  

Ask your source if there's anything else of interest. Something ignored by many.

2 - Indian tigers

I recently read one of your posts in the thread 'Amur Tigers'. You wrote you had contacted a biologist working in India. He told you a number of adult male tigers had been darted in central India. The tigers were actually measured and weighed. One of them, not gorged and not empty, was 285 kg. Is this true? Any other details known about this tiger?

Would he be able to inform us about the dimensions (and weights) of an average adult male in central India? Is he able to compare tigers in central India with those living in other regions?

About the Bengal tigers,

There are two tigers of 280 kg and slightly above. 

One of them was captured by Dr. Jhala in Kanha National Park (central India) and he weighed 285 kg, was fully fed. 
I did ask Dr. Jhala about this tiger´s measurements but no reply regarding that.  

The second one was captured by a coworker of Dr. Jhala in a different region, not Kanha. But definitely either central India or western tiger landscape - Ranthambore. This one was 280 kg and neither gorged nor empty. Again, no information about this tiger´s measurements.

About the averages and comparison of tigers in central and other regions of India, some information was provided (but mostly in respect of weights only). Since Wildlife Institution of India works only with tigers in central and western India, we lack information about tigers from other regions. 

Dr. Jhala told that an average adult male tiger weighs 230 - 240 kg (507 - 529 lbs). Him and his coworkers have collared many tigers. In one of his studies, ¨Demography of a small, isolated tiger (Panthera tigris tigris) population in a semi arid region of western India¨, Dr. Jhala said this - 

Quote:¨The morphometric measurements of RTR tigers captured for radio-collaring were among those of the largest recorded for tigers in India.¨

This was again told to me by his coworker (one who told about the 280 kg tiger). 

As WII works only in central and western India, Dr. Jhala himself said that he cannot tell about tigers from other regions of India, like the tigers of terai. 




 
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Netherlands peter Offline
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( This post was last modified: 12-12-2021, 12:30 PM by peter )

ON THE SIZE OF CAPTIVE AMUR TIGERS - II

II.1 - Introduction

In this post, the dissertation for the degree of Master of S. Weilin, 'Study on growth and development of Amur tigers raising dispersedly' (Northeast Forestry University, 2005), will be briefly discussed. 

Before posting a few scans, I want to let you know our member 'Betty' (many thanks!) was the one who sent me the link to the dissertation and answered a number of questions.   

The dissertation is in Chinese. Only the title page, the abstract and table 3.27 were scanned. The reason is these pages were translated into English. It isn't always easy to understand everything. If you have questions, my advice is to contact 'Betty'.  

II.2 - Location, sample and methods used

The first thing you need to know is the study was conducted in the Hengdaohezi Feline Breeding Center (the Siberia Tiger Park and the Hengdaohezi Wildlife Farm) in the Heilongjiang Province in the northeastern part of China. This facility had about 400 Amur tigers in the summer of 2021. 

I selected one table for this post. This table (Table 3,27, 'Measurement of body size and weight of Siberian tiger') is based on measurements of 114 male tigers and 93 tigresses. All tigers ranged between 6-66 months of age.

According to 'Betty', the tigers were measured in a straight line ('between pegs'). I'm, however, not sure about the method used to measure the height at the shoulder. 

II.3 - Scans

II.3a - Title page


*This image is copyright of its original author


II.3b - Abstract

In total, 224 Amur tigers were measured. Of these, 207 were used for the table below (see II.3c). 

The tigers used for the study lived in the Hengdaohezi Wildlife Farm and the Siberia Tiger Park near Harbin. Although Weilin states there isn't much to choose between both populations, there is a marked difference between male tigers from Hengdaohezi and those from Harbin. Hengdaohezi male Amur tigers (HB 188,5 cm) were significantly shorter than those from Harbin (202,7 cm). The difference in weight (172,7 kg for Hengdaohezi as opposed to 192,1 kg for Harbin) also is remarkable. 

Recent photographs also suggest (referring to ground colour; stripe colour; number of stripes; stripe width; relatively size and shape of the head, and general appearance) both populations seem to be different from each other.   

In immature captive Amur tigers, there is a quite strong relationship between total length and weight. This relationship changes when they, to use the words of Weilin, enter 'puberty'. Females enter 'puberty' at about 30 months, whereas males do so at about 42 months of age. This finding is important, as it's known wild Amur tigers disperse between 18-24 months of age (closer to 18). This means young Amur tigers disperse well before they reach 'puberty'. 

According to 'Betty', the relatively low weight of male Amur tigers living in both facilities could have been a result of a number of problems. Back then (referring to the period 1990-2005), diseases were quite common in both facilities.    
 

*This image is copyright of its original author


II.3c - Table 3.27 

The table says captive Amur tigresses reach their greatest size (referring to HB and weight) at 30 months of age (just before they enter 'puberty'). Captive male Amur tigers reach their greatest size (referring to chest circumference and weight) at 42 months of age. 

In the period they change into adults (between 30-66 months for females and 42-66 months for males), both males and females lose quite a bit of weight. After reaching adulthood (66 months of age), females, although a bit shorter than in the period just before they entered 'puberty', regain the weight lost. This is not the case in males. Adult male Amur tigers are not as large (referring to total length, chest circumference, weight and standing height at the shoulder) as males entering 'puberty' at 42 months of age.   

If the averages in the table are confirmed in other studies, it means captive Amur tigresses need more time to develop into adults than males. Adult Amur tigresses average about 136-137 kg (301 pounds) and 270-271 cm in total length measured in a straight line. Adult males average 187-188 kg (413 pounds) and 309-310 cm in total length measured in a straight line. 


*This image is copyright of its original author

 
II.4 - Conclusions 

I've measured about 20 captive big cats, seen a lot more and have information about the size of captive Amur tigers I consider very reliable. What I saw and read strongly suggests captive Amur tigers, at the level of averages, are the largest (referring to weight, standing height at the shoulder and total length measured 'between pegs') big cats in captivity. This to say I wasn't surprised to find adult females in Hengdaohezi and Harbin to average about 300 pounds and 8.10-8.11 in total length measured 'between pegs'. Same for the total length (10.2) of adult male Amur tigers.  

I was, however, surprised at the average chest circumference (adult Amur tigresses average 122,9 cm and adult males average 142,7 cm). Not one of the big cats I measured, although some exceeded 442 pounds in weight, reached 135 cm. The Amur tigers in the two Chinese facilities are quite robust in this respect. As it's not a result of a large weight (adult females averaged 301 pounds and males 413 pounds), the conclusion is the large chests are a result of constitution. This conclusion later was confirmed in another study conducted in a Chinese facility.  

All in all, I'd say captive Amur tigers in Hengdaohezi and Harbin were (referring to the situation before 2005) quite long and, referring to chest circumference, quite robust. Although the average weights do not seem to confirm this conclusion, it has to be remembered weight often is a result of conditions. If diseases, as 'Betty' said, were indeed quite common in Chinese facilities in those days, it's quite likely it would have shown in the (average) weight of adult tigers.   

II.5 - Photographs 

It seems fitting to conclude the post with a few photographs (from Xinhua). The first photograph was made in July 2021, wehereas the second one was taken in July 2020.


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*This image is copyright of its original author
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ON THE SIZE OF CAPTIVE AMUR TIGERS - III

III.1 - Introduction

In this post, a very recent study, 'Body measurement parameters and body weights of sub-adult and adult Amur tigers (Panthera tigris altaica)', will be discussed. It was published in the Chinese Journal of Wildlife, 2021, 42(4), pp. 965-972. 

The authors, Cui (Y), Liu (D), Mu (G), Gong (M), Xu (H), Li (X), Yang (S), Fan (X), Liu (Y) and Jiang (G), collected detailed information about the weight and 8 body parameters (chest, waist and neck circumference, shoulder and hip height, width of the front and hind palm and total length) of 45 subadult (22♂, 23♀) and 74 adult (40♂, 34♀) captive Amur tigers (n=119). 

Their goal was " ... to explore the growth and development of (captive) Amur tigers ... and to provide a scientific reference for the artificial breeding and protection of the wild Amur tiger ... " (from the abstract). 

The model they developed suggests that " ... shoulder height is an important parameter for assessing the weight and length of the Amur tiger ... " (abstract). 

Again, it was 'Betty' who found the study, sent me the link and answered a few questions (many thanks!). The study is in Chinese, but the abstract and the tables have an English translation. 

I'm not quite sure, but I think all tigers measured were from the Siberian Tiger Park, Harbin. They are a bit larger than those in Hengdaohezi (discussed in the previous post).

III.2 - Scans


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


III.3 - Results

a - Male tigers

As I'm unable to read Chinese, definitions are unclear. Combining Table 2 and Figure 3, I concluded, at least for now, that 2-3 year old males were considered as subadult, whereas tigers of 4 and older were considered as young adults. It's quite likely I'm wrong. Better remember that when you read the post. I'll ask 'Betty' to help out. 

a1 - Length

In contrast to the study discussed in the previous post, male tigers in the Siberian Tiger Park in Harbin did not reach their greatest length before the age of 4, but just before they reached 6 years of age. Adult males averaged 304,3 cm in total length measured 'between pegs' (Table 2). After 6, however, male tigers gradually lost length with age. The number of observations in the category 6-9 years of age, however, is very limited (see Figure 3). 

a2 - Weight

Like in the study discussed in the second post of this series, subadult males peak when they reach 4 years of age (at about 210 kg, see Figure 3). Young adults, in contrast, quickly lost weight. The difference between the Hengdaohezi and the Harbin Amur tigers is Harbin males reached a new peak after reaching 6 years of age. Between 6-7 years of age, they average about 230 kg. One of the males reached 295 kg (Figure 3). After 7, males gradually lose weight. 

a3 - Chest circumference

Subadult males peak at about 4 years of age, when they average well over 150 cm (Figure 3). Between 4 and 5 years of age, however, they lose about 25 cm (...). Mature males (6 years and over) average about 135 cm (Figure 3). The higher average of adult males in Table 2 (141,8 cm), most probably, is a result of the decision to consider tigers of 4 years of age as adults. After age 7, males slowly lose size. 

a4 - Neck circumference

Table 2 says subadult males average 80,3 cm and adults 90 cm. Figure 3, however, strongly suggests the opposite is true (...). Tigers up to 4 years of age average over 90 cm, whereas 5-year old males average just over 80 cm. As males get older, the neck circumference again increases. It's the exception to the general rule that captive male Amur tigers (at least those in the Siberian Tiger Park) lose size after reaching 6-7 years of age.  

a5 - Shoulder height

Table 2 says adult males average 112,2 cm at the shoulder. Using reliable information in other studies and books, I think it's very unlikely the actual standing height at the shoulder of adult males really is over 112 cm. According to 'Betty', the protocol is clear, but then not quite. It could depend on the expertise of those measuring the tiger, we think. Like 'Betty', I think the 'height at the shoulder' was measured when the animals were sedated. For this reason, the results are unreliable.  

In spite of that, the information is interesting. Assuming they measured the height at the shoulder in the same way as hunters did in the recent past (referring to British India in particular), one could conclude the difference between this method and the actual standing height at the shoulder in adult male tigers of large subspecies (P. tigris tigris and P. tigris altaica) could be about 4 inches, perhaps a tad less. 

The difference between both methods in adult male Amur tigers could be about 10%. In this study, adult males averaged 112,2 cm., whereas it's known standing male tigers average, depending on the location, 100-103 cm. The method used by hunters suggested adult male Indian tigers averaged 3.3-3.5 (99,1-104,1 cm). If my assumption is correct, it would mean adult male Indian tigers average 89-94 cm at the shoulder while standing. Exceptional individuals (referring to both subspecies) could be about 4 inches taller (100-105 cm in Indian tigers and 110-115 cm in Amur tigers).   

a6 - Heel width

Table 3 says the average width of the palm of the front foot in captive adult male Amur tigers ranges between 9,6-10,0 cm. Apart from the table published in 2005 (and discussed in the posts I referred to in the first post of this series), there's not much known about the average 'heel width' of wild adult males. Biologists, however, agree the minimum heel width in wild males is about 10,0 cm. 

According to A. Batalov, male tiger 'Ochkarik' has a heel width of about 10,0 cm. This tiger ranges between 160-180 kg in weight. Another male in that district, 'Obor', larger than 'Ochkarik', has a heel width of 12,0 cm. In large wild male Amur tigers, the heel width can exceed 13,0 cm (up to 13,5-14,0 cm).

Back to the Harbin tigers. At age 6, adult males average about 230 kg, just over 10 feet in total length measured 'between pegs' and 9,99 cm in heel width (referring to the palm width of the front paw). My guess is the heel width of a wild adult male of that size would be over 12,0 cm (referring to averages). Assuming the relationship between heel width and weight would hold for all males, one could conclude the difference in heel width between wild adult males and captive males is 20-25%. A significant difference. 

b - Tigresses

Like in subadult males, subadult females peak in many respects before they reach adulthood. The difference with subadult males is peaks in females are less pronounced. Furthermore, most peaks are reached well before they reach 4 years of age. 

In contrast to adult males, adult females continue to grow after they reach 5 years of age. The growth also is more prolonged. At age 8, females are still growing in most respects (see Figure 4). The only exception is the heel width. After 7, females gradually lose width.

The averages for adult females in Table 2, if anything, seem to be quite misleading. At age 8, for example, females do not average 135,4 kg and 270,4 cm in total length. Figure 4 says females of that age average just over 150 kg and about 275 cm (...). 

c - A few remarks 

Although the results seem to point in a different direction, there isn't much to choose between the results of this study and the results of the study discussed in my previous post (referring to the dissertation of Weilin). There are different reasons.  

The first reason is table 2 is misleading to a degree. This is a result of the uneven spread of observations. Most tigers used for the study ranged between 2-6 years of age. The number of tigers of 6 years and older, however, is very limited (see Figure 3 and Figure 4). 

It could be that subadult and young adult male tigers, as is suggested in both studies, really are a bit larger than mature male tigers, but there's not enough information about mature male tigers (referring to both studies) to get to sound conclusions.    

Another reason is the decision to distinguish between 2 groups only: subadults and adults. This decision is not supported by the measurements (see Figures 3 and 4). These indicate there are 3 stages during growth. For this reason, one has to distinguish between subadults (2-3 for females and 2-4 years for males), young adults (4-5 for males and 3-4 for females) and mature adults (males of 6 years and older and females of 5 years and older). 

I'm not saying the results of this study are unreliable, but the lack of data about mature tigers has an effect on the conclusions. For example. The 4 mature females used in this study were quite large individuals. The logical conclusion is mature females are larger than young adults. That conclusion, however, is based on a very small sample. In mature males, it was the other way round. Again, the conclusion (mature males are smaller than young adults) is based on a very small sample. 

The information I found (referring to the table I'll post in a few days) suggests mature male Amur tigers, like the females in this study, continue to grow, both in length and weight, after reaching 6 years of age.  

Anyhow. It is clear there is a difference between the tigers in Hengdaohezi (see the previous post) and those in Harbin. The Hengdaohezi tigers (referring to males only) seem to be decidedly shorter and not as heavy as those in Harbin. Remarkable, as both belong to Panthera tigris altaica. One would like to read a bit more about the possible reasons.  

III.4 - Conclusions

The study discussed in this post is of interest for zoos and those working with captive Amur tigers, because it offers a bit of insight in the growth and development of captive Amur tigers up to about 6 years of age. 

Subadult females (at least those in the Siberian Tiger Park in Harbin) quickly develop up to age 3. Between age 3-5, their body changes. They no longer grow and lose quite a bit of weight. After reaching about 5 years of age, they start growing again. At age 8, they're still growing in most respects (see Figure 4). At that age, they averaged over 150 kg (331 pounds), 275 cm (just over 9.0) in total length measured 'between pegs' and 122 cm (about 4.0) in chest circumference. Three females exceeded 285 cm (9.4) in total length measured 'between pegs', whereas five reached or exceeded 160 kg (364 pounds). 

Subadult males quickly develop until they reach 4 years of age. Between 4-6, they lose quite a bit of weight. After reaching 6 years of age, they start growing again. The period of growth, however, is not as extended as in females. After they reach 7 years of age, they gradually lose length and weight. The only exception is the circumference of the neck. At age 9, males average 195-200 kg (430-442 pounds), about 295 cm (9.8) in total length measured 'between pegs' and 135 cm (4.5) in chest circumference. At their peak, when they're 6-7 years of age, adult males average about 230 kg (508-509 pounds) and 307-308 cm (10.1) in total length measured 'between pegs'. Exceptional individuals reach 320-325 cm (10.6-10.8) in total length measured 'between pegs' (see Fig. 3). Only one of the males exceeded 250 kg. He was 295 kg (651 pounds).   

Table 2 suggests the averages for adults are different. This is a result of the decision to consider young adults as 'adult'. The conclusion I got to, however, is far from solid as well. The reason is only very few mature tigers were included in the study. 

The study doesn't offer a reason for the difference in development between mature males and females. It is quite likely the conclusion regarding the different development of mature males and females I got to will prove to be incorrect. The reason, again, is the very small sample (referring to tigers of 6 years and older). 

In the abstract, the authors said " ... shoulder height is an important parameter for assessing the weight and length of the Amur tiger ... ". The problem is this parameter was measured in an unclear way. The height at the shoulder has to be measured when tigers are standing. A female reaching 95 cm (just over 3.1) measured in this way is very tall. Same for a male reaching 110 cm (just over 3.7). 

The study has reliable information about the size and development of subadult and young adult Amur tigers. If you want to know a bit more about the size and development of mature tigers (6 years and older), however, you have to look elsewhere.  

III.5 - About the study

I read the study more than once. Although interesting all the way, I still feel some parts were a result of rushwork. Here's some of the reasons. 

One is the character of Table 2. The measurements, as was stated before, strongly suggest one has to distinguish between subadults, young adults and mature adults. The authors no doubt got to that conclusion as well. In spite of that, they decided to distinguish between subadult and adults only. The only logical outcome of this decision can be a confusing, somewhat misleading, table.

Two is they apparently didn't notice the discrepancies between Table 2 and Figures 3 and 4. Subadult males, as Table 2 suggests, didn't average 170,8 kg. At least, not if 3-year old males would have been included. They weren't, because this department (3-year old males), apart from 1 male, was completely empty. This means only 2-year old males were weighed. It also means the average of subadult males is incomplete, and therefore, inaccurate. Same for subadult females.  

Three is the lack of information about mature tigers (6 years and older).  

Four is they, based on the model developed, conclude the height at the shoulder could be the best indicator of the size of tigers. This although the method used to measure the height is unclear (referring to the protocol) as well as inadequate (it's bound to produce unreliable results).  

Five is the abstract is a somewhat shallow summary of some of the findings. The wealth of data (see Figures 3 and 4) offers the authors a lot of room for a decent analysis.  

The amount of information collected, however, is impressive. Apart from the dissertation of Weilin discussed in the previous post in this series, it's one of the very few about he growth and development of subadult and young adult Amur tigers born and raised in captivity. Figures 3 and 4 in particular offer plenty of opportunities to get to a few conclusions.
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ON THE SIZE OF CAPTIVE AMUR TIGERS - IV

IV.1 - Introduction

In this post, another recent study will be briefly discussed. I'm referring to 'Per- and polyfluoroalkyl substances (PFASs) in blood of captive Siberian tigers in China: Occurrence and association with biochemical parameters', Wang (Y), Yao (J), Dai (J), Ma (L), Liu (D), Xu (H), Cui (Q), Ma (J) and Zhang (H), in: Environmental Pollution (2020).

Our member 'Betty' (thanks again) sent me the link to the article. This time, I'll only post the title page, a credit author statement, the abstract and a table I found in the 'Supporting Information'. I'm referring to table S1 ('Information on sample collection, sex, age, and weight of captive Siberian tigers in Harbin Tiger Park, China').

IV.2 - Scans


*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

  
IV.3 - Table S1 

This article was published about a year before the study discussed in the previous post was published. Like in that study, the tigers used for this study were measured in the Harbin Siberian Tiger Park, China. I'm not saying the sample could have been identical, but it's quite likely some of the tigers used for the study discussed in the previous post were used for this one as well. Or the other way round. 

In order to refresh your memory and prevent a lot of clicking, I decided to repost Figures 3 and 4 of that study. This time, both Figures are a bit larger. The larger size will enable you to see all details. 

Here's Figure 3 (trends in male tigers):


*This image is copyright of its original author


And here's Figure 4 (trends in female Amur tigers):


*This image is copyright of its original author


In this study, 54 young adult male tigers (4-5 years of age) averaged 214,7 kg (475 pounds). In the previous study, young adult males averaged about 200 kg (442 pounds). 

Young adult tigresses (3-4 years of age) used for this study averaged about 140 kg (310 pounds). In the previous study, they also averaged about 140 kg. 

Young adult males used for this study are 33 pounds heavier than those used for the study discussed in the previous post, but one has to remember individual variation in this age category (young adults) is quite pronounced (see Figure 3). The difference could be a result of selection or coincidence, that is. 

The thing to remember is young adult male Amur tigers in the Harbin Siberian Tiger Park, depending on the way the sample is selected, average 200-215 kg (433-475 pounds), whereas young adult females in that Park average 135-140 kg (300-310 pounds). 

I'm not sure how young adult males and females, weightwise, compare to mature tigers (females of 5 years and older and males of 6 years and older), because only few mature tigers were weighed. Based on the study discussed in the previous post, I think it's safe to conclude mature tigers and tigresses start growing again after they reach 5 (females) or 6 years (males) of age. In male tigers, this new period of growth doesn't seem to be as prolonged as in females. This conclusion, however, is based on small samples. 

IV.4 - Conclusions

The study discussed in this post is well written and interesting. Interesting, because it shows that some chemical substances (referring to PFASs) not only affect marine mammals, but also terrestrial mammals like captive Amur tigers. 

In the Amur tigers in the Harbin Siberian Tiger Park, dietary food accounted for over 70% of the total daily intake of PFASs, indicating that " ... meat consumption is a predominant exposure pathway in tigers ... ". The researchers also found " ... positive associations between higher exposure to PFASs ... and elevated serum levels of alanine transaminase (ALT), a marker of liver damage ... " (abstract). 

As it's very likely pollution also affects terrestrial wild animals, " ... comprehensive health assessments of PFAS burdens in wildlife are needed ... " (abstract). 

The tigers used for this study were young adults. The 54 males (4,57 years of age) averaged 214,7 kg (475 pounds), whereas the 62 females (3,77 years of age) averaged 140,7 kg (310 pounds).
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ON THE SIZE OF CAPTIVE AMUR TIGERS - V

V.1 - Introduction

When discussing the dissertation of Weilin (see post 2,574) and the study of Cui et al. (see post 2,575), I said not everything was clear. The reason was the language (both the dissertation and the study are in Chinese). For this reason, I decided to contact 'Betty'. 

A few days ago, the questions I had were answered. In this post, they will we briefly discussed. 

V.2 - Shoulder height

The first question was how the height at the shoulder was measured in the dissertation discussed in post 2,574 (Weilin) and in the study discussed in post 2,575 (Cui et al.). 

Weilin measured the distance from the shoulder blade to the sole of the foot in a straight line. You may remember 8 males of 42 months of age averaged 101,43 cm, whereas 4 males of 54 months of age averaged 98,50 cm. In the largest sample, 25 males of 66 months averaged 96,64 cm. 

According to 'Betty', the tigers in the dissertation published in 2005 and in the tigers in the study published in 2021 were measured in the same way. In spite of that, the results were very different. In the study published in 2021, subadult (2-3 year old) captive male Amur tigers averaged 107,80 cm, whereas adult males (4 years and older) averaged 112,15 cm. If we add the tigers were from the same facility (the Harbin Siberian Tiger Park), the question is why the difference is so pronounced. 

The answer is we don't know. According to 'Betty', the definition used in the study published in 2021 is somewhat unclear. It's also possible those involved in measuring the tigers had little experience and, for this reason, were unable to execute the method described in the protocol. This, however, is just an assumption. 

What is clear, however, is that the (unclear and unsound) method used in the both the dissertation and the study was applied in different ways. This is the reason very different results were produced. If you would conclude methods developed to get to an estimate about the height at the shoulder are bound to produce very flexible, if not unreliable, results, you could be quite close. 

V.3 - Subadult and adult

In post 2,575, I wrote it wasn't easy to understand the differences between Table 2 (averages of subadults and adults) and Figures 3 and 4 (trends). As the information in Figures 3 and 4 is more reliable (the dots, after all, represent all measurements), I concluded Table 2 was somewhat misleading. I assumed it most probably was a result of the decision to distinguish between subadults and adults only. 

According to 'Betty', this assumption is correct. The authors of the study distinguished between subadults (2-3 years of age) and adults (4 years and older) only. The only logical outcome of this decision can be a confusing table. 

V.4 - Conclusions

Like in other large mammals, there are pronounced differences between subadult, young adult and mature tigers. Young adults lose the fat accumulated in the first years of their life during the transition to adulthood. For this reason, they often lose weight in that period. When the transition has been completed, they start growing again. The information collected in the Harbin Siberian Tiger Park strongly suggests growth has different stages. This is the reason one has distinguish (referring to males) between immatures (<2 years of age), subadults (2-3 years of age), young adults (4-5 years of age) and mature animals (6 years and older). Takes a bit of work, but it's the only way to produce accurate tables.   

As to methods developed to get to a reliable estimate of the height at the shoulder. Most of them, as the dissertation and study discussed in posts 2,574 and 2,575 again show, are either unclear or difficult to apply. 

The only reliable method is to measure the actual standing height of adult animals. This is the method V. Mazak used. According to him ('Der Tiger', 1983, pp. 190), adult females (n=5) range between 82-88 cm, whereas adult males (n=7) range between 96-106 cm. Females exceeding 90 cm and males exceeding 110 cm at the shoulder are exceptional.
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ON THE SIZE OF CAPTIVE AMUR TIGERS - VI

VI.1 - Introduction

It may sound a bit strange, but it isn't easy to find information about the size of captive big cats. If you find something, chances are the information is unreliable. I'm not only referring to estimates (often indicated by rounded numbers), but also to selection. Not seldom, you'll find information about the largest individuals only. It's much more difficult to find information about average-sized or small tigers and tigresses.  

In contrast to what you would expect, zoos and big cat facilities contribute in this department (selection) as well. Nearly all big cats measured and weighed in zoos suffer from problems (neglect, old age or a disease) severely affecting their weight. 

In what way is a table about the size of captive big cats produced? 

One first has to find reliable information. The article has to be printed and additional information has to be added. You then need to develop a system to store the information. Months later, a table is produced. It's only then you realize important information is lacking. You also realize the goal to use adults only is very difficult to achieve. If you want a decent sample, you often have no other choice but the drop the standards to a degree. 

When you have a table meeting a few thresholds (referring to reliability, a decent sample, a good spread and overview), you'll notice it's necessary to include the additional information you collected. As you don't want to produce an unreadable table, decisions have to be taken. And then you realize the table has no averages, meaning more work is needed. How get to averages? Should every record be included? And what about individuals of which you have different weights? 

What I'm saying is it took me a long time to get to a result. With a 'result', I mean a table offering good information and overview at a glance. 

A few words about the sources wouldn't be out of place. Most of the information was found in books and articles. I also found quite a bit in local newspapers (referring to the USA in particular). Information 'Betty' found on a few (Korean and Japanese) blogs was included as well. The vital statistics of the Amur tigers and skulls I measured were added. I also used information I found in a number of posts in the thread 'Captive lion and tiger weights'. This means our members also contributed to the table. Last but not least, I used a few videos.  

VI.2 - About selection

VI.2a - Introduction

Selection has different faces. No matter what you do, it can't be avoided. This has to be accepted. Experience says those interested in a particular species tend to select information confirming their ideas. Most members of forums know all about it and try to keep their feet dry. A bit over the top, I think. There's nothing wrong with a bit of preference. Not seldom, it's the drive behind all kinds of quests. Furthermore, most of us learn to deal with the tendency to select the most impressive records over time. 

But most is not all. Some of those interested in big cats continue to develop in the department of preference. So much so, they, many years later, graduate with honour. When they reach that stage, preference developed into bias. This means they no longer control the urge to produce extra-large lions or tigers out of nowhere. Not seldom, they also invest a lot of time in dismissing records of exceptional representatives of the 'wrong' species. When they join a forum to enter 'debates' about big cats, problems are bound to erupt. Their outspoken opinions often prevent a productive exchange. Sooner or later, the climate is affected. Those posting good information usually are the first to go. When that happens, the owners of a forum have no choice but to intervene. 

The efforts of those driven by outspoken opinions, however, also have a positive effect in that members interested in good information become more aware of the consequences of preference. In the end, the result often is a wider scope and more balanced exchanges.    

VI.2b- About the tables in the next post 

The tables in the next post have information about both large and small individuals. Both tables, in fact, are well-stocked in the department of small tigers. In order to offer you a bit more about the way information was selected and used, I'll discuss a few tigers used for the tables. One of them is the smallest adult male Amur tiger I know of, whereas the other made headlines because of his large size. I'll also discuss an average-sized male.  
 
VI.2c - About 'Pavel'

Finding information about average-sized males, like I said in the introduction (VI.1), is far from easy. Information about the length and weight of captive Amur tigresses is even more rare. And then there is the department of small male Amur tigers. I'm referring to adult male Amur tigers not much, if at all, larger than a decent adult male Indochinese tiger.  

Tigers like 'Pavel'. He most probably was the smallest of the litter when he was born ('Pavel' means 'small' in Russian). I'm not sure, but think he was born in the Lincoln Park Zoo in Illinois. In October 2017, when he was about 9 years of age, 'Pavel', partly as a result of his interesting genes, was sent to the Smithsonian National Zoo in Washington. Two years later, tigress 'Nikita', from the Bronx Zoo in New York and also valuable, joined him. The attempt to introduce 'Pavel' to 'Nikita' didn't result in problems, but their meeting, as far as I know, also didn't result in offspring. 

When they met, 'Pavel', at age 11, was 341 pounds (154,68 kg), whereas 6-year old 'Nikita' was 297 pounds (134,72 kg). Did his size have an effect? I don't know, but it seems very unlikely. When a male and a female are introduced to each other in a zoo, you never know what will happen. Tigers decide at the very last moment. Not seldom, their choice surprises all involved. If they don't like each other, anything is possible. Females have been killed by males more than once.   

Anyhow. Less than 2 years later, 'Pavel' was moved to the Indianapolis Zoo. According to that zoo, 'Pavel' was 315 pounds (142,89 kg). This means he lost 26 pounds (11,8 kg) in about 2 years. Compared to the other male Amur tiger in the Indianapolis Zoo, 'Maxim', he lacked 35 pounds. This means 'Maxim' was a small male Amur as well (350 pounds). I can almost hear you say adult male Amur tigers of that weight surely are few and far between. The answer is negative. I found quite a few newspaper articles with precise information about adult male Amur tigers well shy of 400 pounds. 

For some reason, adult male Amur tigers in American zoos seem to have lost quite a bit of size after the turn of the century. This is not the case in females.    

VI.2d - About 'Igor' 
 
Most of you no doubt heard about tiger 'Igor' of the Odense Zoo (Denmark). He featured in quite a few newspaper articles and videos. Some of them were posted in the thread 'Captive lion and tiger weights'. Tiger 'Igor' wasn't exceptionally long or tall, but robust. Unfortunately, he was never measured and weighed in his best years. When he got older, he was troubled by problems affecting his health. 

In 2010, when he was treated for dental problems, he wasn't weighed. Some years later, just before his death, he was. In bad shape, 'Igor', then thin as a rail, still was " ... around 230 kilos ... " (quote from a PM of the Odense Zoo - see the List of References). As I was unable to find anything about his weight in his best years, 'Igor' entered the table at 230 kg. This although it's very likely he exceeded 600 pounds (272,2 kg) in his prime. In one article, they said he was 250 kg. In another, he was 300. We'll never know, but I do know large male Amur tigers like 'Igor' often exceed 600 pounds in their prime.  

Here's 'Igor' when he was treated for tooth problems. This photograph is from 2010, when he already had lost quite a bit of weight:


*This image is copyright of its original author

In his best years, he was a bulky male:


*This image is copyright of its original author


VI.2e - About 'Semyon'

In November 2014, in the thread 'Captive lion and tiger weights', our member 'Amnon242' posted a newspaper report about a male tiger in the zoo of Dvur Kralové (CZ). A few days later, I found another article about the same tiger. Both newspaper articles had a few photographs. 

In the first article, tiger 'Semyon' was " ... a 150-pound cat ... " (...). In the second, published a day later, he was 190 kg. Same for length. In the first article, he was 299 cm (HB 203 cm, tail 96 cm), whereas he was 325 cm in the second. A significant difference. And a problem, as I had to find the correct information. 

Using the photographs, I concluded the information in the first article most probably was correct. This, however, wasn't true for the weight. The weight in the second article was correct. The conclusion was 'Semyon' was 299 cm in total length measured 'between pegs'. In the second article, the length, most probably, was measured 'over curves'. His weight was 190 kg. A bit below expectation for a male of that size, but 'Semyon', at 17, was an old tiger and it's known captive male Amur tigers often lose a lot of weight when they get older. 

Here's 'Semyon':


*This image is copyright of its original author


VI.2f - About multiple weights, decisions, calculations and averages

Before I started on the averages, a lot of decisions had to be taken. Decisions depend on your goal. My aim is to produce a table reflecting the (range in) size of healthy captive male Amur tigers. I can hear you say that shouldn't be a problem. Select healthy adults and you have your answer. 

Wrong. There're so many problems I wouldn't know where to start. What is adult in captive Amur tigers? And what about large youngsters used for breeding purposes? Do I want to include tigers severely affected by disease, old age or abnormal conditions (referring to neglect and obesity)? Do I want to include exceptional individuals? What is exceptional? And what about tigers of which different weights are available? 

What I'm saying is selection, like I said at the start of this paragraph, is difficult to avoid. The question, therefore, is which criteria are used. The answer is it depends. There's no general rule that can be applied in the same way each time. In order to give you an idea, I'll to discuss a few tigers used for the tables.  

When you read the table, you'll notice some tigers have different weights. Tiger 'Amur' (no. 03 in the table), for example, was 192 and 255 kg. Both weights have a deep black colour. This means decisions were taken. In this case, I decided to use both weights. There were two reasons. In his prime, 'Amur' was estimated at 250-260 kg. I didn't decide for 250 or 260, but for 255 kg. Directly after death, he was 192 kg. The significant loss of weight was a result of a disease. A disease that killed him. As most captive Amur tigers perish as a result of a disease, I decided to use that weight as well. Using both weights (255 and 192), the result was 223,5 kg. This weight is far from correct (in his prime, 'Amur' was a long, tall and robust tiger), but it's the best I can do in the circumstances.  

His son 'Benjamin' (no. 05 in the table) also died as a result of a disease. Directly after death, he was 128 kg. In this case, I decided against using that weight. One reason is he perished in his prime. Another is he was badly affected by the disease that killed him. Although a bit smaller than his father, he no doubt doubt would have been well over 200 kg in 'normal' conditions. Using the weight of a tiger badly affected by a disease won't contribute to a realistic picture of healthy captive Amur tigers. That doesn't mean the weight will be erased. It will be recorded, because it shows a disease can have significant effects. This is important for zoos.  

Tiger no. 82 in the table is exceptional. The weight (442,4 kg) is reliable, but I don't know if he was very large or a very obese tiger. As he's over 100 kg (221 pounds) heavier than the second heaviest, I decided against using the weight. This, however, doesn't mean it was an imaginary tiger. He's very real. According to 'Betty', who has an extensive and reliable database, some male tigers in Chinese zoos well exceed 300 kg. At least 3 of them are over 400 kg (...).    

Tiger 'Rocky' (no. 69 in the table) seemed (referring to the video) to be an average-sized Amur tiger. At age 14, he was 216 kg. At age 18, he was 190 kg. I decided to use the average of both weights (203 kg) for the table.    

Tigress 'Nikita' (no. 31 in the table) ranged between 124,7-139,7 kg in her prime. The average (133,0 kg) was used for the table. Tigress 'Ai' (no. 37 in the table) was 159 kg in her prime. At age 18, she was 113,3 kg. The significant loss of weight not only was a result of her age: she suffered from many health problems. For this reason, I decided against using her weight at age 18.

VI.3 - Conclusions

This post is an introduction to the next. That one has the tables I referred to in this post. The aim of this post is to tell you a bit more about (finding and assessing) data and how to use them for, say, a table.  

The first thing you need to remember is you have to learn to learn to distinguish between estimates and accurate information. The second thing you need to remember is most information is a result of some kind of selection. You have to be aware of the effects. My advice is to use as many sources as possible. When the sample is large enough, chances are the effects of selection, to a degree, will even out. 

Information about the size of captive Amur tigers in Chinese facilities (referring to the dissertation, the study and the article discussed in the previous posts) is reliable, but the spread in all samples I saw is limited. This has an effect. Same for the conditions. The tigers in the Harbin Siberian Tiger Park and Hengdaohezi live in large groups. The decision to keep them in this way has disadvantages. One of them is diseases spread easily. According to our member 'Betty', tigers in Hengdaohezi and the Siberian Tiger Park in China suffered from diseases in the recent past. This resulted in relatively low averages. The problems were solved, but the new approach had unforeseen consequences (referring to photographs of obese tigers that made headlines not so long ago). I don't doubt this problem will be solved as well, as the Chinese are serious about (wild and captive) Amur tigers. 

All in all, I'd say captive Amur tigers, at the level of averages, really are the largest big cats in captivity. This, of course, is without the products of selective breeding (referring to white lions and tigers, all kinds of crosses and lions bred for hunters on quite a few 'farms' in South Africa). 

When going over the tables, one has to remember most captive Amur tigers are never measured and weighed. This includes exceptional individuals. Here's one of them to finish the post:


*This image is copyright of its original author
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Netherlands peter Offline
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( This post was last modified: 03-26-2022, 05:58 PM by peter )

ON THE SIZE OF CAPTIVE AMUR TIGERS - VII

VII.1 -  Introduction

This post has both tables (males and females) I referred to in my previous post. It also has a lot of additional information (abbrevations, notes, remarks and references). For this reason, I decided against supplementive remarks and comments. 

VII.2 - Abbrevations

When reading the tables, you'll need this:


*This image is copyright of its original author


VII.3 - Amur tigresses

Here's the table with females. You'll find the averages in this next paragraph (VII.4):


*This image is copyright of its original author


VII.4 - Averages of Amur tigresses

Captive Amur tigresses (n=27) average 138,1 kg (almost 305 pounds). Although a bit shorter than the captive Amur tigresses in Hengdaohezi and the Harbin Siberian Tiger Park, they compare in most respects. You'll find more details in 'Remarks' (directly below the table). Finding information about tigresses, by the way, was more difficult than finding information about male Amur tigers: 


*This image is copyright of its original author


VII.5 - Male Amur tigers

The table has 85 entries. Deep black numbers mean decisions were taken (see 'Notes' and 'Remarks'): 


*This image is copyright of its original author
 

*This image is copyright of its original author


*This image is copyright of its original author


VII.6 - Averages of male Amur tigers

Captive male Amur tigers average 224,2 kg (almost 495 pounds), 205,7 cm (6.9) in HB and 303,1 cm (just over 9.11) in total length measured 'between pegs'. Although a bit heavier than the tigers from Hengdaohezi and the Harbin Siberian Tiger Park discussed in the previous posts, they compare in most respects.

The averages are more reliable than the averages for females, because of the sample size (referring to weight in particular): 


*This image is copyright of its original author


VII.7 - Notes and remarks

In this paragraph, you'll find a bit more about some of the tigers in the tables: 


*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


VII.8 - Sources

In this long paragraph, you'll find the sources of the information used for the table:


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


*This image is copyright of its original author


VII.9 - Closing remarks

When going over the tables, you'll notice there are quite significant differences in size between Amur tigers in European, American, African (referring to South Africa), Chinese and Japanese zoos. As far as I can see, Amur tigers in European zoos are larger than elsewhere. The more east you go (referring to Europe) the larger the tigers, so it seems (watch the last word, as I'm not sure). 

Here's a male from Hungary that wasn't measured and weighed when he was sedated. Watch the fore-arms:


*This image is copyright of its original author

I'm unable to tell you anything about the reasons. It could be a result of coincidence, but it's also possible there are specific reasons. Before the turn of the last century, Amur tigers in American zoos were as large as those elsewhere (see the list of references). After the turn of the century, however, the number of reports about small tigers increased. Tiger 'Pavel' isn't the only one well below 400 pounds in his prime. It seems to be a pattern, but I'm not sure. If there is a pattern, it doesn't hold for females. I don't have the time to produce a table with the average weight in different continents, but it could be one of you is interested. 

Those who evaluated historic records of wild Amur tigers noticed a marked decrease in size after 1970. My feeling is it isn't very different in captive tigers, but I could be wrong. 

Over the years, I talked to many people I considered as very experienced in the tiger department. They told me an average adult male Amur tiger in good health today is 240-260 kg in his best years. Male tigers ranging between 160-200 kg in their prime are uncommon. Same for males well exceeding 300 kg. My guess is the average I found wouldn't surprise them. Without the Americans, the average most probably is quite close to what they told me. They also thought Amur tigers used to be bigger in the recent past. One reason Amur tigers lost size over time, they said, was the extermination of Manchurian tigers after 1950 or 1960.
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ON THE SIZE OF CAPTIVE AMUR TIGERS - VIII

VIII.1 - Introduction

This post has a story I saw on a blog. The first time I read it, I couldn't make head or tails of it. Over time, however, that changed. Although it in some ways almost compares to a poem, my adviced is to take it serious. The author knows about tigers in general and this one in particular.  

The story is about tiger 'Bengari' (no. 49 of the table). In most respects, 'Bengari' was of average size. The difference with other tigers is he was much more robust. His head in particular was impressive. Although he was offered many opportunities to pass on his genes, 'Bengari' didn't succeed. For some reason, he, as far as I know, killed all females to which he was introduced. 

Very sad, but it happens every now and then. Keepers do everything they can, but some males never breed. Same, by the way, for wild male tigers. I know of different well-documented stories.   

I first heard about this tiger about a decade ago, when our mod 'GrizzlyClaws' posted about him on a thread of the former AVA forum. I printed the post and stored it. A few months ago, 'Betty' sent me the link to the blog. 

This is my last post of this year. I wish all of you a Merry Christmas and a happy New Year. 

VIII.2 - 'Bengari'

When scanning the story, I missed a few sentences. A pity, but I assume those interested will be able to find the original.  


*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
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(12-24-2021, 02:18 PM)peter Wrote: ON THE SIZE OF CAPTIVE AMUR TIGERS - VII

VII.1 -  Introduction

This post has both tables (males and females) I referred to in my previous post. It also has a lot of additional information (abbrevations, notes, remarks and references). For this reason, I decided against supplementive remarks and comments. 

VII.2 - Abbrevations

When reading the tables, you'll need this:


*This image is copyright of its original author

*This image is copyright of its original author

VII.3 - Amur tigresses

Here's the table with females. You'll find the averages in this next paragraph (VII.4):


*This image is copyright of its original author

*This image is copyright of its original author

VII.4 - Averages of Amur tigresses

Captive Amur tigresses (n=27) average 138,1 kg (almost 305 pounds). Although a bit shorter than the captive Amur tigresses in Hengdaohezi and the Harbin Siberian Tiger Park, they roughly compare in most respects. You'll find more details in 'Remarks' (directly below the table). Finding information about tigresses, by the way, was more difficult than finding information about male Amur tigers: 


*This image is copyright of its original author

*This image is copyright of its original author

VII.5 - Male Amur tigers

The table has 85 entries. Deep black numbers mean decisions were taken (see 'Notes' and 'Remarks'): 


*This image is copyright of its original author

*This image is copyright of its original author 

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

VII.6 - Averages of male Amur tigers

Captive male Amur tigers average 224,2 kg (almost 495 pounds), 205,7 cm (6.9) in HB and 303,1 cm (just over 9.11) in total length measured 'between pegs'. Although a bit heavier than the tigers from Hengdaohezi and the Harbin Siberian Tiger Park discussed in the previous posts, they roughly compare.

The averages are more reliable than the averages for females, because of the sample size (referring to weight in particular): 


*This image is copyright of its original author

*This image is copyright of its original author

VII.7 - Notes and remarks

In this paragraph, you'll find a bit more about some of the tigers in the tables: 


*This image is copyright of its original author

*This image is copyright of its original author


*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author


*This image is copyright of its original author

*This image is copyright of its original author

VII.8 - Sources

In this long paragraph, you'll find the sources of the information used for the table:


*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*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

VII.9 - Closing remarks

When going over the tables, you'll notice there are quite significant differences in size between Amur tigers in European, American, African (referring to South Africa). Chinese and Japanese zoos. As far as I can see, Amur tigers in European zoos are larger than elsewhere. The more east you go (referring to Europe) the larger the tigers, so it seems (watch the last word, as I'm not sure). 

Here's a male from Hungary that wasn't measured and weighed when he was sedated. Watch the fore-arms:


*This image is copyright of its original author

*This image is copyright of its original author
I'm unable to tell you anything about the reasons. It could be a result of coincidence, but it's also possible there are specific reasons. Before the turn of the century, Amur tigers in American zoos were as large as those elsewhere (see the list of references). After the turn of the century, however, the number of reports about small tigers increased. Tiger 'Pavel' isn't the only one well below 400 pounds in his prime. It seems to be a pattern, but I'm not sure. If there is a pattern, it doesn't hold for females. I don't have the time to produce a table with the average weight in different continents, but it could be one of you is interested. 

Those who evaluated historic records of wild Amur tigers noticed a marked decrease in size after 1970. My feeling is it isn't very different in captive tigers, but I could be wrong. 

Over the years, I talked to many people I considered as very experienced in the tiger department. They told me an average adult male Amur tiger in good health today is 240-260 kg in his best years. Male tigers ranging between 160-200 kg in their prime are uncommon. Same for males well exceeding 300 kg. My guess is the average I found wouldn't surprise them. Without the Americans, the average most probably is quite close to what they told me. They also thought Amur tigers used to be bigger in the recent past. One reason Amur tigers lost size over time, they said, was the extermination of Manchurian tigers after 1950 or 1960. Could be just a rumour, but I heard it more than once.

The best form to describe this big investigation is that this is a "labor of love". I am amazed by the amount of data that you got at this point, and certainly these tables are going tobe mandatory in future conversations and debates.

Thank you again for providing this information. Happy
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(12-19-2021, 04:09 PM)peter Wrote: According to V. Mazak ('Der Tiger', 1983, pp. 190), adult females (n=5) range between 82-88 cm, whereas adult males (n=7) range between 96-106 cm. Females exceeding 90 cm and males exceeding 110 cm at the shoulder are exceptional.

About standing shoulder height, I have this new image showing the measurements taken by Vratislav Mazák himself on several captive tigers. I focused in Indochina, Bengal, Amur and Sumatran tigers. As Mazák presented the real pictures of the largest tigers that he measured, I used them in the comparative image, and I also added the giant tiger from Duisburg with 110 cm in standing height (measured by other person). Plus, I add the smallest tiger measured by him, which is an small Sumatran tigress that is probably of the same size os the smallest Bali and Javanese tigress on record.


*This image is copyright of its original author


Here you can get a good idea of how big is a cat of over 100 cm, and we can discard any "popular record" of lions over 120 cm in height, as this is something that was achieved only by the Pleistocene Panthera cats. A cat of 110 cm is already a big cat and is possible that the record tiger and lion of 114 cm in hunting records taken "between pegs" were about 110 cm or a little less measured in the real standing position.
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