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

[GuateGojira]

Body size of the tiger - final compilation

The tiger (Panthera tigris) is a carnivore mammal member of the Felidae family, is the largest felid on Earth and an obligated carnivore that inhabit the Asian continent. It is the top of the food chain but even then it is in great danger of extintion because of the humans.

For long time ago, I investigated this animal, I have read almost all the books available about this species, focused in those from modern scientific investigations, which started since 1963 with the investigation of Dr George Schaller in Kanha NP, India. Previous to that, very few Zoologist studied the tiger and most of the information came from hunters that took more time in explaining how to kill it than how to understand it. However, something that was writen a lot in the old litterature is about the size of the animal, but even then there was a lot of controversy and there are several documents about that, explaining the correct form to correctly measure them. At the end, even with all the information available, it was very important to choose the correct and reliable information over the one full of exagerations. This is the case with the Bengal tiger and sources like Brander, the Maharaja of Cooch Behar and Hewett, amoung others, give us the most reliable information about the true size of the tiger. Now, with the other subspecies, the information is scanty and in some cases almoust inexistent. With the Amur tigers, old records mentioned specimens of 4 meters long and up to 384 kg, but when Slaght et al. (2005) investigated them it shows that almost all the old records are unverified or were just copy-past from the reports of Baikov. In the other side of the coin, there is only one body measurement for a single male Bali tiger and none for females, plus there is not a single weight about that population. So, where it came the information that we normally use and that populates the web (including Wikipedia in ocations) in these days? Well, the obvious answer is Mazák (1981):

*This image is copyright of its original author

This table from the document of the Zoologist Vratislav Mazák from 1981 is the base for the calculation of the size of the tigers, and for many years it was the only reliable. Previous attempts were made, for example the report of Guggisberg in his book of 1975 which dedicated almost 4 pages only to that topic, but it was Mazák who stablished the ranges and added also information about the skull size from specimens that he personally measured, which provide the best degree of reliability. However, his table was not perfect, as he did not presented averages, sample sizes and included captive specimens, like with the Amur tiger. In fact, he is the one that popularized the idea that the Amur tiger is/was the biggest tiger subspecies. Other problem is that he used estimations with the populations that did not had data, like for example the Bali tiger and now we have many people preaching those figures but they do not know that are not real, just calculations and in the best case, are just an educated guess.

At the end, some modern Biologists tried to provide compilations about size and weight for tigers, for example Sunquist & Sunquist (2002) and Barlow et al. (2009) but the problem is that the first one provided scanty information and used old records from Russia and provided unreliable body sizes and the second source mixed captive with wild specimens, which provided incorrect averages. So it seems that even in modern times it is really hard to found reliable information about the size of the tiger.

In this case, since 2003 when I started to participate in debates and when I started a serious study on tiger's biology, ecology and behaviour, I manage to compile several records of size and weight for all the tiger subspecies and with the help of others, like @peter for example, I manage to get sources that I don't even knew that existed. Following the process explained in Slagth et al. (2005) I classified the measurements and weights that are reliable from those than no, using those that match the "highly reliable" and "generally reliable" cathegories like the main sources. On the measurements I tried to use only those "between pegs" but that is a method normally used with the Bengal population, but rarely used with the other populations, which sadly decrease the sample size. After many years of clasifications, depurations and reading many books, it was until the 2018 that I manage to compile all the information in order to create new tables. However tragedy happens and I lost all the information gattered for at least 5 years. Since then, I decided not to post anymore and retire from forums, however some posters that still provide incorrect information in other forums were the reason why I decided to return, but this time I did not had the time to make the investigations that I used to do. So I decided to recover all the information that I could rescue from old backups and from my own memmory, trying to search the original papers and my old comparison images that thankfully have the sources of the information on them. The effort paid good results as I enlarged the samples and found more information from other subspecies, so until the last year I manage to recover all the information about the size of the lions and the tigers, and I am still completing that of the jaguars and leopards. Believe me, gattering all that information is time consuming and that is something that I don't have anymore.

At the end, in February 2020 I managed to complete the comparative image of the lion size with all the reliable information that I could found, here are the links:
https://wildfact.com/forum/topic-on-the-...eo?page=20  -- post 293
https://wildfact.com/forum/topic-on-the-...eo?page=21  -- Post 302


In this case, I only needed to do the same think with the tigers, the animal that I love the most and the real inspiration for all these years of study of Biology like an amateur investigator. The next image is the result of all that effort, document reading and even personal communications with the experts. It is a big work of accuracy, patience and love and I think that the results are incredible. So here is my final comparative image of the size of the tiger:

*This image is copyright of its original author

I used the new classification of the IUCN which states that only two subspecies of tigers exist, but also I leave the old subspecies names as the issue is still not settle. The image is self-explanatory (please read the small letters and they have important details) but I will like to share some other details to avoid confusions.

* Bengal tiger: The figures in both measurements and weights includes the Sundarbans specimens, however in a foot note I added the average weights excluding that population (Mainland only), which is 210 kg (150 - 272 kg -- n=160) for males and 138 kg (105 - 177 -- n=96) for females. In a future I will create an image only with the diference between the Mainland and the Sundarbans population with the new format (I don't like the old one and the comparative images look larger than the average specimen). For details on the average calculations and also for details on the results on the Nepalese tigers weights and samples, I will leave these links:


https://wildfact.com/forum/topic-modern-...rs?page=23  -- post 341
https://wildfact.com/forum/topic-modern-...rs?page=24  -- posts 356 and 358
https://wildfact.com/forum/topic-modern-...rs?page=25  -- post 362

https://wildfact.com/forum/topic-lion-an...er-heights  -- post 3
https://wildfact.com/forum/topic-who-is-...ur?page=29  -- posts 430, 433 and 434
https://wildfact.com/forum/topic-who-is-...ur?page=30  -- post 440

If someone ask about the huge record bengal tigers, those were not included for obvious reasons but here is the link where I discussed that, posts No. 391 and 404, check it: https://wildfact.com/forum/topic-modern-...rs?page=27

So, at the end, the Bengal tiger is still the largest tiger subspecies/population and the heaviest cat in modern times.


* Amur tiger: I decided to include the few reliable records from tigers measured and weighed by Russian Zoologists, which are few but important, just like I have done with the Bengal tigers. For information you can check my old document of 2015 about the size of the Amur tiger, although that document needs to be updated as now we know that all the specimens were measured, apparently, along the curves. Knowing this, the image of the Amur tiger was scalated smaller than the Bengal tiger as the measurements "along the curves" produce longer results than those "between pegs". Even then, I still believe that Bengal and Amur tigers were of the same body size (based on skulls at least) and both represent the pinnacle of the species.

* Indochinese tiger: There are no particular remarks on it, just that I decided to separate them from those of Malaysia, following the genetic research. For details in the modern measurements please check these links:
https://wildfact.com/forum/topic-indo-ch...ers?page=5  -- posts 68 and 69
https://wildfact.com/forum/topic-indo-ch...ers?page=6  -- post 81

* Bali tiger: I did not included any body mass for the Bali tigers as the figures of Mazák are estimations and there are no real weights in litterature. I made years ago a calculation using an isometric aproach and using the method of Sorkin (2008) and Christiansen & Harris (2009) but I decided not include it, as the image shows only real measurements, no calculations. This is because I want to keep it as original as posible.

Maybe in this moment there are other details that scape from my mind, but like I allways say, if you have a question over a particular point, you are free to ask.


Greetings to all, have a nice day. Reply