About methods, measurements, errors, baits and the art of debating

[peter]

3 - METHODS TO MEASURE BIG CATS

Just before I started on this post, I read WaveRiders' last post (post 31) in his thread 'Body Lengths and Weights of Tigers, Lions, Bears and other Carnivores: how to understand correctly' in the Carnivoraforum. The issues he discussed are almost identical to those I had in mind. As we seem to have quite different views in nearly all departments, I decided to use this post to address the points he made and explain why I have a different opinion. In order to keep the post readable, I decided to use paragraphs. I also added a number of scans. The points he made are discussed from the top down. Here we go.


a - A difference of opinion on how tigers are measured

WaveRiders' post in Carnivora, to get things clear, was a response to my previous post in this thread. That post was a kind of evaluation of the exchange between WaveRiders (in the blue corner) and Guate (in the red corner) in the previous days. If you want to know what happened, I'd advice to read this thread completely and then move to the thread WaveRiders created in Carnivora (see above). Or the other way round. Anyway.

In my evaluation, I said the exchange of information had resulted in a more or less clear sky. This regarding the method used to measure tigers in India (Nagarahole), Nepal (Chitwan) and Russia (Sichote-Alin). Based on what I read, I concluded it is very likely biologists in the three regions mentioned above measure tigers in more or less the same way. Although different posters contributed to the debate, Guate in particular has been very active.

Based on what I read, I concluded tigers were stretched before they were measured. Then the skull was raised in such a way that the top of the skull, the spine and the tail constituted a more or less horizontal line. The tape was then run from the tip of the nose to the end of the last bone in the tail, following the curves of the body. One could say the tiger was measured 'over curves' after it had been stretched. All clear so far.

Now for the questions. Was the tape pressed to the body at all points (referring to the skull and the spine) or not (1)? If not, to what degree did the tape follow the curves of the body (2)? Based on what I read (referring to the emails of Miquelle and Sunquist), my guess is the tape was pressed to the body in Russia and not (quite so rigorously) in Nepal. And Nagarahole? Ullas Karanth wrote it was done in the same way as in Russia, but Sunquist, who saw two tigers measured in Nagarahole, apparently saw no difference with the method used in Nepal.

For now, I would say the method used to measure tigers is about similar in Nagarahole and Nepal. Russia could be somewhat different. But Ullas Karanth (see the scans from his book below) wrote the method used is similar in India, Nepal and Russia (see the first scan below). It is a standard method. What to make of that?

Guate's drawing, perhaps, can be regarded as an illustration of the method used in all regions. Although the drawing is slightly different from the descriptions in the emails mentioned above, it would make sense to measure a sedated tiger in the way Guate suggested: it can be done with a few people only and the result would be more accurate than when done in the way Miquelle described.

This is how it should be done:

*This image is copyright of its original author

And this, if Guate is right, is how it was done in Nagarahole, Chitwan and Russia:

*This image is copyright of its original author

  
Remember the conclusion I got to (see above) is based on an interpretation of the information I saw, meaning it is an opinion. Although I could be wrong, I have reason to think Guate could be close (see below). This is why.  


b1 - The Miquelle emails 

WaveRiders, who disagrees with Guate's interpretation of the information posted, wrote the two emails of Miquelle were very clear. In the first one he said tigers in Russia, after the body is stretched, are measured along the curve of the body. In the second email, he said the tape is pressed to the body of the tiger at all points. The result of this method can only be a measurement 'over curves', WaveRiders concluded.

I would have agreed in nearly all cases, but not in this one. In my previous post, I wrote it is more likely that the tape, like in Guate's drawing above, is pressed to a few points of the body. I agree this is a remarkable interpretation of Miquelle's description. One could even make a case for a twist. Why was that? The answer is Miquelle's description doesn't fit the information available. One could even say it contradicts the descriptions of Ullas Karanth and Sunquist. Ullas Karanth first.   


b2 - Ullas Karanth on methods and measurements (in 'Tigers', 2001)

It is about point 4 and the following sentence (at the right). The crucial parts are " ... Most biologists ... " and " ... follow a standard method ...". This means there was a standard method to measure tigers and it was there before the book of Ullas Karanth was published. It also means it is very likely that it was applied in Nagarahole, Chitwan and Russia. Ullas Karanth apparently was sure of it, as he, on the next page (not the scan below, but the one at the bottom of this post) wrote tigers in the three regions mentioned more or less compared. This, I think, means he was sure they were measured in the same way: 
 

*This image is copyright of its original author

        


b3 - Sunquist on the method used to measure tigers in Chitwan

Have another look at the scan above. Point 4: " ... Most biologists now measure the length of tigers along the contours of the spine ... ". This can only be done if the tape is pressed to the spine. At all places. Just like Miquelle wrote in his second email, remember? 

Ullas Karanth and Sunquist knew each other quite well (see the info posted by Warsaw on Carnivora). Ullas Karanth specifically refers to Chitwan (see the pages above and the following page). Also remember that Sunquist wrote he was in Nagarahole when two tigers were measured. He didn't say he, methodwise, saw anything out of the ordinary, did he?

How did Sunquist measure tigers in Chitwan? He didn't say anything in his book, but made up for it by responding to questions time and again (my compliments). His emails have been posted. Chitwan tigers were stretched before they were measured. Then the skull was raised in such a way that the top of it and the spine and the tail constituted a more or less horizontal line. The tiger was then measured with a cloth, following the contours of the spine.

Wait a minute. Following the contours of the spine? Does that equal 'over curves'? No, it doesn't. Not in this case. They did press the cloth to the body at some points, but it wasn't done in the rigorous way typical for a measurement taken 'over curves'. The method used was close to a 'between pegs' measurement, he concluded. Clear.


b4 - Conclusions

Sunquist is crucial, because of his detailed emails and his follow-up on statements that were not well understood. He was in Nagarahole and saw sedated tigers measured. As he didn't write they used an incorrect method when they were measured, one has to assume they were measured in the same way as in Chitwan. Meaning the method described by Ullas Karanth above was used in Chitwan. This is important (1). How was this method applied in Chitwan (I opt for Chitwan, because Sunquist offered details, whereas Ullas Karanth did not)? The result compared to the result of a measurement taken 'between pegs', Sunquist wrote. Also important (2). As Ullas Karanth wrote tigers in Nagarahole, Chitwan and Russia were measured in the same way, the conclusion is tigers had to be measured in the same way in Russia as well. Again very important (3).

Now for the problems. 

You can't deny that Ullas Karanth wrote that tigers were measured following the contours of the spine, can you? No, I can't. Ullas Karanth is very clear in his description. But it also is a fact it was done in the same way as in Chitwan. And how was it done in Chitwan? Sunquist wrote the contours of the spine were followed to a degree, but it wasn't done in the rigorous way typical for a measurement taken 'over curves'. Furthermore, before the tiger was measured, the body was stretched, thus reducing the number of curves. When it is also known that the skull was raised and that the (top of the) skull, the spine and the tail constituted a more or less horizontal line which was measured pressing the cloth to a few points of the body, the conclusion is the tiger was measured in a nearly straight line.

From the description of Sunquist, one could say, as he did himself, that the tiger was measured 'between pegs'. This he underlined more than once. This means that the result of the method used was very close to the result of a measurement taken 'between pegs'. Not quite, but very close. Finally, it means that the description of Ullas Karanth, although very clear in itself, perhaps, wasn't quite correct, if not inadequate. We know this because of Sunquist's emails and details. Again important (4).

Could be, you probably think. But what about Ullas Karanth and Miquelle? What do they think of this interpretation? Well, we don't know about Ullas Karanth. Guate contacted him, but he didn't answer questions on the method used. Miquelle, on the other hand, did offer details in his emails. He wrote the tiger was stretched, but the tape was pressed to the body at all points. This has to mean tigers in Russia were measured in a different way, doesn't it? 

I don't think so. Ullas Karanth wrote the method used is a 'standard' method used everywhere. This means it was used in Russia as well. This is why Ullas Karanth was able to compare the results of the measurements. If we add that Ullas Karanth, like Miquelle, wrote tigers were measured along the contours of the spine, whereas Sunquist wrote they were measured in a straight line, one could conclude they apparently disagree. Maybe they did measure tigers in a slightly diffferent way in the end? Back to square one?

No. My guess is the method used is just difficult to describe. Tigers are not measured 'over curves' and they are not measured 'between pegs'. It is done in a different way. One could say it is a new method. Before he is measured, the tiger is stretched, thus reducing the number of curves. Then the skull is raised. Same for the tail. In this way, a more or less horizontal line is created. This line is not measured with a steel tape, but with a flexible tape or a cloth. This is done in order to be able to follow the contours of the spine. According to Sunquist, it isn't done in a rigorous way. The tape is pressed to the body at some points, but the line measured is very close to a straight line. Hence his conclusion that the tiger is measured 'between pegs'. 

As a result of the complicated procedure, it isn't easy to get to an accurate description of the method used. Same for the result in that it isn't quite clear if it compares to the result of a measurement taken 'over curves' or a measurement 'between pegs'. There is a lot of room for those involved in descriptions, that is. This, most probably, is the reason the descriptions offered by Ullas Karanth, Sunquist and Miquelle are somewhat different. A very important conclusion (5). One could say the confusion on the method used is a result of the complicated procedure and be close.                    


b5 - The best way to test the conclusions discussed above

My conclusions are based on deductions. I think I'm right, but it is possible that the 'standard' method, in spite of everything said, might be applied in slightly different ways in different regions. 

The only way to find out is to contact Miquelle, Ullas Karanth and Sunquist. I propose to send them 3 drawings ('between pegs' - 'over curves' - 'over contours with the skull raised and the spine straightened') with a detailed and accurate descriptions and ask them. They should have the last word.


c - Different methods yield different results

In my previous mail I wrote the method used by today's biologists, although quite similar to the method used in northern India a century ago (I'm referring to the method known as 'over curves'), would yield quite different results. In my opinion, the new method produces a result that almost compares to the result of a measurement taken 'between pegs'. My guess is the difference between both method would be 1-3 inches or even less. This opinion is based on my experience and the drawing of Guate.

Compared to the other method ('over curves'), the difference would also be limited. One has to remember that there are different ways to measure a big cat 'over curves'. Based on what I read, I'd say the way it was done in the northwestern part of India was the most reliable. Sir John Hewett and others (like for instance Dunbar Brander) who had experience with both methods ('over curves' and 'between pegs') thought the difference was 2-5 inches (2 inches when the tiger was short and 5 when long). Remember tigers in northern India were, and still are, long. 

WaveRiders wrote that my information (on the difference of 2-5 inches) was " ... partial and vague ... ". But it wasn't 'my information', WaveRiders. This is Sir John Hewett in 'Jungle Trails in Northern India' (1938):

*This image is copyright of its original author

 

*This image is copyright of its original author

 


So the most experienced concluded the difference between both methods in northwest India was 2-5 inches. I agree the difference was more pronounced in Cooch Behar, Assam and the Duars (referring to the book of the Maharajah), but the method used ('over curves') in northwest India apparently was applied in a slightly different way than in the northeast. 

And this is the problem with this method ('over curves'): it is unreliable. Everyone with experience agreed on that conclusion.


d - Methods and reliability

A century and a half ago, a debate erupted in British India. It was about the method used to measure big cats. The reason was some hunters produced 12-footers on a regular basis, whereas others, using the same method, never saw a tiger reaching 10 feet. Time for a debate, it was concluded. It wasn't easy to get to a conclusion. Than Sterndale joined the debate. He said the method used ('over curves') was unreliable and proposed a new method ('between pegs'):

*This image is copyright of its original author

This is the method used by biologists and zoologists in Europe. I talked to many and all agreed a big cat has to be measured 'between pegs'. The reason is this method produces similar results when a cat is measured by different people. It compares to the way humans are measured: from top of skull to the floor in a straight line and no shoes. A man or woman of 5 or 6 feet straight in Germany will be as long in Peru when measured in the same way with the same equipment. 

Did V. Mazak agree? Most certainly. This is from the third edition of his great book on tigers:

*This image is copyright of its original author

V. Mazak, like many starting biologists and zoologists, was misled by hunters reporting on enormous tigers in Russia. He published the records of Barclay and Baikov and was severely punished for it. From then on, he only used records of big cats measured 'between pegs'. This is the method he used himself when he measured a number of captive Amur tigers. To his collegues, however, it didn't make a difference. One big mistake usually means you're no longer taken very serious. 

However. Humans and double standards are very good friends. Pocock published an article about tigers in the JBNHS in 1929. Although very interesting, it was loaded with errors and mistakes. On size. The reason was he too was either uninformed or misled. One reader wrote a letter which was published in the same magazine. It wasn't very flattering, but Stockley was a hunter and Pocock a would-be zoologist and thus it didn't count:

*This image is copyright of its original author

*This image is copyright of its original author

There's a lot more, but this is enough to illustrate the point made. The point is there are two methods to measure big cats. As one of the two produces unreliable results, zoologists do not use it. They use the other ('between pegs') for the reason mentioned above. Confirmed? Yes. Everywhere.

Anything to add? Yes. I measured captive big cats and used both methods to test the experiences of others described above. One adult male Amur tiger and one adult male African lion were used for an experiment. After I had explained both methods to those present, both animals were measured by three who said they were interested to give it a try. They measured both cats on their own (assisted by keepers), recorded the results and compared them with those of the others later. And now for the classified results. When measured 'between pegs', the differences were limited to within an inch. Quite an achievement when it is known that the animals selected were large. When measured 'over curves', however, the differences were very pronounced. I would say everything experienced by others was confirmed. 

How about today's biologists working in India, Nepal and Russia? Well, they stretch and straighten the animal and also raise the skull, in this way reducing the number of curves and creating a virtual horizontal line. When the animal has been prepared for a straight line measurement, however, they measure the length by following the 'contours' of the spine. To a degree.   

Why did they decide for this method? I don't know. I think the method is unreliable (this is why I don't use the results for my tables), but they no doubt have good reasons.


e - Two ways to measure a big cat 'between pegs'


In my previous post, I wrote the new method used in Nagarahole, Chitwan and Sichote-Alin, in spite of the decision to measure the length along the spine, probably produces a result that compares to a measurement taken in a straight line ('between pegs'). As both methods are different, the question is why did I got to that conclusion?

The answer is there are two ways to measure a big cat 'between pegs'. A century ago, most tigers measured were measured on the spot 'as they fell'. They were stretched and the skull was raised. Same for the tail. Then a measurement was taken between the pegs at the tip of the nose and the tail. The problem was the measurement often was taken on the ground and not at the height of the tail. The distance between the insertion of the tail and the floor (4-7 inches) wasn't measured, that is. The problem could be solved by following Sterndale's instruction (to measure head and body and the tail seperately). This means there are two ways to measure a big cat 'between pegs'. Based on what I read, my guess is most were measured in the first way.  

Today's biologists, if Guate is right (referring to his drawing), is accurate in that the length is measured at the correct height (at the insertion of the tail). As the cat is straightened and the skull is raised as well, a measurement following the contours of the spine, if the tape is not pressed to the spine at all points, almost compares to a measurement taken 'between pegs' (referring to the last method used to measure a big cat 'between pegs'). 

WaveRiders disagreed with this opinion and said the length of a cat measured 'between pegs' was done at the correct height. A remarkable conclusion, as I had to learn it the hard way. More, indirect, confirmation is in the hundreds of books I read in that I never saw any details on how this method ('between pegs') was used. They just wrote the cat was measured 'between pegs'. In most cases, only total length was given. To me, this points in the direction of two pegs only and a distance measured at the ground, not at the height of the tail.


f1 - The relation between length and weight in Indian tigers a century ago

In my previous post, I wrote WaveRiders had proposed to deduct " ... 14-19 kg. from every average just to make sure they (the tigers) were empty ... ". He said he specifically referred to Cooch Behar, the Duars and Assam. This is true. But he was confused about the five Kruger males weighed by Stevenson-Hamilton a century ago and I saw him prepare a significant increase in weight. Furthermore, he wrote he has a lot more on tigers, weights and stomachs. I do not doubt he has.  

I admit applying 'Seen one tree, seem 'm all' at this stage may seem a bit harsh, but it is a fact that WaveRiders has been decreasing lengths and weights of tigers from the day he arrived. A pity he didn't produce something similar on lions and bears, but one has to accept preference usually results in one-way traffic. 

As for tigers and weights. Good information from different parts of India was published in the recent past (about a century ago). The tables below were a result. They were posted before. Have a good look, as they have more info than you think.


f2 - Northern India and Nepal

*This image is copyright of its original author

Sir John Hewett only reported on the total length of tigers shot in northern India and Nepal. The 18 males actually weighed averaged 435,7 lbs. Notice the remarkable difference between tigers over 440 lbs. and those below that mark. Those over 440 lbs. were 101 lbs. heavier and significantly longer. Also notice the difference between those weighed (n=18) and those not weighed (n=22). Those not weighed were quite a bit longer. Than watch the 5 Nepal tigers shot in an unmolested region: they were very long.

The question is how to get to an average for all. Shouldn't be that difficult. When done, compare the outcome with the (adjusted) average of the 7 males weighed in Chitwan (in Sunquist & Sunquist, 2002).        


f3 - Cooch Behar, the Duars and Assam

*This image is copyright of its original author

This is the best database I know of by far. The males actually weighed averaged 460,68 lbs. and 295,46 cm. 'over curves'. Those not weighed were slightly shorter, meaning it is likely the real average was a bit lower. Again notice the big difference between tigers over 440 lbs. and those who fell short of that mark. Of those weighed, 7 were described as gorged. At similar head and body length, they were 60 pounds heavier than the other tigers weighed. One often reads tigers can totally gorge themselves, but if we divide 60 by 452, the result is just over 13%. Impressive, but not even close to 20%.  

Based on the information above, I concluded tigers in northwest India and Nepal most probably are a bit longer and, in particular, heavier than those in the northeastern part of India. Nepal tigers could be the longest and heaviest wild big cats, although those in northern India seem to compare.        



f4 - The Deccan, northwest India and Nepal and Cooch Behar, the Duars and Assam

*This image is copyright of its original author

This table shows the differences in length between the regions used for the table were limited. Remember the Deccan sample is older than the others. One could say there is a clear connection between total length and weight in every region. In general, longer tigers are significantly heavier than shorter tigers. The more pronounced the difference in length, the larger the difference in weight.

Is total length a more reliable indicator for weight than head and body length? And if affirmative, could there be another factor behind total length, like head and body length? The Cooch Behar sample says no. It really is about total length: the longer a tiger, the heavier. Explanation? I don't know, but it could be age. Tigers grow for a long time. After reaching adulthood, they continue growing in length for some time, but the real increase is in bulk. That's what experienced hunters said and that's what records suggest. Is it also seen in skulls? Yes. Skulls of older animals are a bit longer, but the most remarkable difference is in zygomatic width and, again, weight.        

Although WaveRiders wrote length (referring to lions and tigers) has to be expressed in head and body length, everything I found suggests it is about total length. In tigers, that is.

As to the difference in head and body in both. A few years ago, I compared all animals of which I had details (adult males only). The conclusion was Indian male tigers were about 4 inches (a bit less) longer in head and body than African male lions, most of these from eastern and Southern parts of Africa (all animals measured 'between pegs').


g - Provocations

In my previous post, I wrote there was (and still is) a lot of confusion on the method used to measure tigers in India, Nepal and Russia. Some of the mist was cleared, but it wasn't a result of the documents written by biologists. Although Miquelle and, in particular, Sunquist helped, most of the work was done by one poster in particular.

WaveRiders didn't agree with this conclusion. A provocation, he wrote. I'll tell you about provocations, Waveriders.

Read the first scan again. Than read the one below. Concentrate on the points underlined and numbered. You know why they were, as it is clear you've been following me for a long time. I sincerely respect Ullas Karanth and all others mentioned in my posts. I really do.

I know many biologists are not that interested in size, methods and measurements, not should they be. It is about the survival of the tiger. But to turn the world upside down and quoting from unreliable sources (referring to Heptner and Sludskij) is close to misinforming. Not saying it was a result of intent (I'm sure it wasn't), but it happened and many read his book. He wasn't the only one. As far as I know, V. Mazak, who paid for one mistake, is one of the very few who delivered original and reliable data on tigers. 

*This image is copyright of its original author

    

        
h - WaveRiders

Some years ago, you joined a debate about extinct big cats on AVA. Guate says he enjoyed your contribution, but I didn't. In my opinion, you treated him and many other participants as confused schoolboys. Apart from your attitude, I saw an agenda and decided to say hello. You quickly understood and left. Good decision.   

This year, you joined our forum. You again immediately went for Guate. As people develop all the time, I was initially very lenient. You had the opportunity to show things had changed, that is. It is a fact you repeated yourself. Apart from the bloody arrogance and the agenda, it is perfectly clear you are unwilling, or unable, to interact in a way accepted everywhere in real life. 

When things got heated, I had no choice but to confront you with a few things. As there was no response, I concluded you had left. My guess was you was headed for the Carnivora forum and as I also suspected a new attempt to continue the flame war you started, I set a small bait. You went for it, thus exposing yourself in no uncertain way.

It is quite clear it wasn't about Guate. The real target is the one who appreciates his effort and, with Sanjay, asked him to join the team. The same poster who, twice, decided you're bad news for any forum. The old posts you used to go for him clearly prove you have been following him for a very long time. Typical for an obsession of impressive dimensions. There also was a plan. 

In Carnivora, you got another chance to show you are capable to adjust and interact in a productive way. In spite of the attempts to encourage you, the result was disappointing. Your last post in the thread mentioned above (in your thread on Carnivora) is quite telling in this respect. Below are a number of quotes: 


" ... already re-started to twist words either of scientists and of other posters ... and, essentially based on these twists, he is declaring victory of the interpretation he is still going to ... support ... "

" ... If Peter fails to respects the terms of peace, I can anticipate that Peter ... will not have to be surprised if another very harsh contention, ..., will soon be resumed. I can also predict that if another war will have to be afforded by myself I will do my best in order that this unwelcome war to be essentially is something between Peter and me, with the hope that Peter, the Commander in Chief of the opposite army, will not leave alone his Generals and Troops as he did in the second part of the just finished firth animal interforum thermonuclear war ... "

" ... If the tactics used by Peter ... will be to hammer the internet ... and they do not respect ... all terms of the peace just done ... bad consequences will arise and they will not be disappointed ... " (last sentence of your post).  

                
Your last post tops anything I've seen on forums and without doubt qualifies for direct admittance in an institution. The remarks on the unprecedented number of victims in both World Wars (described as 'casualties') would convince even the most cynical readers. I don't like it one bit. 

This post, which took me a long time, underlines I would be interested in a debate, but someone driven by distrust (if not outright paranoia) who consistently opts for suspicion, aggression, insult and everything else connected to a lack of confidence every time he is faced with something he doesn't like, will close every door leading to interaction sooner or later. I repeat it is a pity that a man whose passion took him to Africa to talk to the brotherhood apparently isn't able to overcome the problems described in this paragraph.   

As to the debate. I hope the three tenors (U. Karanth, Miquelle and Sunquist), when confronted with the 3 drawings and the detailed descriptions, will produce something of interest for you. The way you operated, however, closed the door for me. In other words, I lost my interest. I will no longer read your posts at Carnivora, let alone interact. The debate has been concluded, that is. You also are banned. A debate is not a war loaded with insults and threats, but a civilized exchange of arguments needed to get to a good conclusion. Say hello to King Leo from me, 

Peter. Reply