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

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Dr Karanth’s opinion about the size of the tiger: Where is the confusion?
 
Yesterday, I received a pleasant surprise, when I received the full chapter about the tiger from the new book “Mammals of South Asia – Volume 1 (Eds: AJT Johnsingh and Nima Manjrekar). University Press” from 2013 and the chapter was written by no other than the great Dr Ullas Karanth. With its 19 pages, it is a jewel on tiger knowledge, although there are some points that will be interesting to discuss (as I am not agree with them), like the origin of the Caspian tigers, the lion-tiger relationship and the “subspecies” issue.
 
Obviously, when I read the part of the size and weight, I was excited as I was hoping to see “new” data, but it was just a copy-paste of previous documents, although the data seems accurate. However, I took the liberty to compare this his figures with his previous documents and guess what? There are important changes and I discovered that the management of his sources are incorrect. 1. The Tiger: Power and Fragility (1997):
Let’s begin with his first size description in 1997 from the document “The Tiger: Power and Fragility”:
“Siberian tigers can weigh more than 300 kilograms. The Indian tigers are smaller with average males weighing around 200 to 250 kilograms and females a 100 kilos less. Indian tigers are about 155 to 225 centimetres long including head and body, with an additional tail length of 75 to 100 centimetres, if measured correctly along the body curves. However, many old shikar accounts report a nose to tail-tip distance, measured straight between wooden pegs (and, as a way suspected, sometimes between pegs of whisky) making it difficult to get accurate size estimates from them.”
Source: http://savingwildtigers.org/karanth.html
 
This phrase caused a great controversy about why he believed that measurements “over curves” where more reliable than “between pegs”. Other thing, the only tigers in India with 225 cm in head-body are those measured in the very old literature and from animals measured “over curves”. He also repeated the old cliché that Amur tigers can weight 300 kg while Bengals don’t. Thankfully, this figures were forgotten and his next documents stated other figures and other quotes.
 
2. The way of the tiger (2001):
His best and most famous book makes a better description about the size of the tigers in “south east Asia”, not India alone (take this in count):
[img]http://i.imgur.com/eF1hli8.jpg" class="lozad max-img-size" alt="" title="">

*This image is copyright of its original author

*This image is copyright of its original author

Here, he explained the two methods to measure tigers and makes the first claim that old hunting records are mostly “incorrect” and he quotes Pocock here. However, he ends his statements saying that modern scientists measure the tigers “along the contours of the spine”, which apparently means that is the same “over curves” method. However, I think that the problem is more at the words used and semantic, rater than the method itself. To measure a tiger in “straight line”, we don’t need to use “pegs” and in fact, no one use pegs anymore. Scientists stretch the tape in the back of the cat along the contours, but in ANY part say that they follow all the curves of the body, like the old hunters, for the contrary, the description present that the tape was in the flesh and based in Dr Sunquist description and several photographs, the tape is stretched straight in the back and is not stick to the curves of the body. In simple words, the tape is "along" the contours but it is not "following" the curves. Now, on the Amur vs. Bengal issue, he now accepts the fact that they are of the same size, based in scientific measurements of tigers in Nepal, India and Russia. This time, he don’t quote sources, just put the data, which seems surprisingly equal to that of Mazák (1981).
 
3. Tiger Ecology and Conservation in the Indian Subcontinent (2003):
In this document, published in the Journal of the Bombay Natural History Society (Vol. 100), he describes the same measurements, but now he quotes his sources, which seems Pocock (1929), Sunquist (1981) and his own “unpublished” data:

*This image is copyright of its original author

 
Again, the figures are the almost the same than those of Mazák (1981) and the maximum weight of the tigresses was diminished from 175 kg to 160 kg. Other thing, as he don’t believe in the “subspecies” separation, he still quotes the size for the entire “south east Asia” region, not only India. In this point, I guessed that the weight of 175 kg was from Burma and not from India.
 
4. Chapter 34 – Tiger Panthera tigris (2013):
Now, here is the last description of the size of tigers, again in “south east Asia”:

*This image is copyright of its original author

*This image is copyright of its original author

This seems like a summary of his previous books, but this time, he quotes the book of 1939 of Pocock and not the one of 1929. Based in the scans posted by @peter, the book of 1929 is the one that used the incorrect measurements (over curves) and don’t showed any weight. On the other hand, the book of 1939 is the one that use only measurements “between pegs” and do quotes weights from India and Burma.
 
It seems that this is the last statements and should be quoted for true, or not?????
 
5. Pocock (1939):
Here are the pages of the last book of Pocock and his description of the size of India-Burma tigers:

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

Taking a deep and slow read, the figures that quotes Pocock don’t match at all with those of Dr Karanth in any of this publications, here are the results, presented as ranges, like Dr Karanth do (weights of Rowland Ward were not included):
 
Males:
Weight: 160 – 259 kg
Total length: 264 – 313 cm
Head-body: 173 – 221 cm
Tail length: 76 – 92 cm.
 
Females:
Weight: 132 - 157 kg
Total length: 239 – 277 cm
Head-body: 158 – 175 cm
Tail length: 89 – 97 cm.
 
I included the figures of Burma too, but still, they don’t match with the data that Dr Karanth supposedly quoted from Pocock. I ask, what was he reading??? 6. Sunquist (1981):
The document of Dr Sunquist is very famous and hardly needs a description, so here is the table:
[img]http://i.imgur.com/UCWfYED.png" class="lozad max-img-size" alt="" title="">

*This image is copyright of its original author

 
The results, on ranges:
 
Males:
Weight: 200 – 227+ kg
Total length: 287 – 310 cm
 
Females:
Weight: 116 - 164 kg
Total length: 251 – 282 cm
 
Some of these figures surpass those quoted by Dr Karanth, so, what is happening here?
 
7. Unpublished data:
We can guess that these "unknown" data that is still not published will fill all the gaps between the quotes, but still there is no explanation about why he still quotes the same figures of Mazák (1981) instead of the sources that he claim to show???
 
As far we know, only four tigers were captured in Nagarahole, these are:
 
Specimens:  Total length  Tail length     Weight (adjusted)
T-01                293                 101                 209 kg
T-02                248                 87                   177 kg (145 kg?)
T-03                311                 107                 227 kg
T-04                289                 100                 215 kg
 
Still, if we add these figures to those of Sunquist (1981), the results are:
 
Males:
Weight: 200 – 227+ kg
Total length: 287 – 311 cm
 
Females:
Weight: 116 - 177 kg
Total length: 248 – 282 cm
 
8. REAL quote:
If we compile the real data from Pocock (1939), Sunquist (1981) and the four specimens that Dr Karanth measured and weights in Nagarahole (Sunquist & Sunquist, 2002), these should be the real ranges:
 
Males:
Weight: 160 – 259 kg
Total length: 264 – 313 cm
 
Females:
Weight: 116 - 164 kg
Total length: 239 – 282 cm
 
Tail length (overall): 89 – 97 cm.
 
As we can see, the result is somewhat different than that in Dr Karanth books, while his quotes are, in fact, a clear copy-paste from Mazák (1981). Besides, despite his statements that the measurements “between pegs” were unreliable (Karanth, 1997), he still quotes Pocock (1939) which only rely in this type of measurements, which are the most reliable, but still from hunting sources.
 
Now, my question is where he gets the tail length and the shoulder height??? None of his sources quote that figures, however when I dig a little more, check what I got:

*This image is copyright of its original author

 
Yes, is Dunbar Brander (1923), and check his data:
 
Tail length: 76 – 114 cm
Shoulder height: 91 – 112 cm.
 
From my point of view, I think that this is the real source of those particular measurements (in round numbers), although he only quotes a second hand source for that (Pocock, 1939).
 
My conclusion is that the correct paragraph should stay like this:
 
“The typical range of body dimensions and weights (based on Brander 1939, Pocock 1939, Sunquist 1981, Smith et al. 1983, Karanth, unpubl. Data) for South Asian tigers are as follows: Male tigers weight 160-261 kg and females 116-177 kg, showing substantial sexual dimorphism. Because tigers may eat 15-35 kg of meat in a meal, the period elapsed since feeding has a substantial effect on they recorded weight. The total length of adult males is 264-313 cm and that of females 239-282 cm, including a tail length of 76-114 cm. Height at the shoulder is 91-112 cm.”
 
Or using round numbers if you like:
“The typical range of body dimensions and weights (based on Brander 1939, Pocock 1939, Sunquist 1981, Smith et al. 1983, Karanth, unpubl. Data) for South Asian tigers are as follows: Male tigers weight 160-260 kg and females 110-180 kg, showing substantial sexual dimorphism. Because tigers may eat 15-35 kg of meat in a meal, the period elapsed since feeding has a substantial effect on they recorded weight. The total length of adult males is 260-310 cm and that of females 240-280 cm, including a tail length of 75-115 cm. Height at the shoulder is 90-110 cm.”
 
I still don't see the point to mention the stomach content, as it suggest that all the high values are do to gorged specimens, when the reality is completely different, still I put them here as he put it too.

That is my appreciation about how the paragraph should be written, and prove that many times we are used to use the sources from “reliable” people, but at the end, just a deep review can show if that “data” is accurate or not.
 
Maybe this post and all the scrutiny of the data could sound too hard for a normal animal enthusiast, but for those that search for the most accurate and exact data, this type of examples show that this issues are normally irrelevant for the normal writer/reader, and mistakes are made, even in “official” documents. Dr Karanth is without any doubt one (if not the best) of the top experts on tigers, on they ecology, biology and social relationships, but in the size issue, I have my doubts, specially at the light of this data.

What do you think guys, it is necessary to go so far, or we can stay with the "official" although not so accurate numbers? [img]images/smilies/huh.gif[/img]
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