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

[peter]

(10-04-2015, 05:19 AM)GuateGojira Wrote:

(10-03-2015, 08:30 PM)peter Wrote: AMUR TIGER SIZE

After the debate on methods was concluded recently, the question is how long Amur tigers (Panthera tigris altaica) really are. The method used to measure them is a new one and the results, I think, can't be compared to measurements taken 'between pegs'. It seems to be close, but not quite. Based on what I read and my experience with measuring, I would deduct 1-3 inches for now. This means males would average not 294 cm. in total length, but about 287-291 cm. 'between pegs' (and 185-190 cm. in head and body length). I didn't find any reason to adjust the weight Guate mentioned (about 190 kg. or 420 pounds). Could be a bit more, as Miquelle thought males average 430 pounds.   

Well, it is fair to remember that only three tigers had stomach content during its capture, at least this is what the reports showed. This means that over 90% of the other specimens had little or no stomach content (let's remember that Amur tigers eat less often, because of they low prey base). So, the figure of 190 kg for males and 121 kg for females stand.

Now, on the size side, I think it is unfair to discard the measurements presented by the Siberian Tiger Project. Although the email of Dr Miquelle suggest that some press was made on the tape, that was probably minimum and just to sustain the tape, not pressing on the curves to enlarge the size like the old hunters. Check this image again:

*This image is copyright of its original author

They do press the tape but just to sustain it as they are following the contour. At the end, they measured the straight line between the nose to the root of tail. I have found an article in the JBNHS write by Hugh Murray, that suggest the use of a very similar technique and the result is just a difference of 1 to 1.5 inches (2.5 to 4 cm) between this method and that one "between pegs". Check it:

*This image is copyright of its original author

So, in this case, the "corrected" total length "between pegs" of the male Amur tigers would be about c.290 cm and a head-body of c.190 cm, still similar to the Bengal tigers.

Is important to not ignore the fact that scientists are not measuring the animals to found "record specimens", so there is no reason to press the tape the same number of times like the old hunters, Dr Miquelle state it clearly, read the email again.

1 - THE METHOD USED TO MEASURE TIGERS THEN AND NOW 

I knew about the letter of H. Murray to the JBNHS, Guate. The method he used, however, is different from the method used in India (Nagarahole), Nepal (Royal Chitwan) and Russia (Sichote-Alin). When a tiger was measured by Murray, he made " ... one man hold the tape on the point of the nose and another man on the very end of the tail ... ". He then pressed the tape " ... down into the hollow of the back, thereby increasing the length by an inch or an inch and a half ... ". This means the distance between the point of the nose and the end of the tail was measured in a straight line with the tape (apart from the two points mentioned) not pressed to the body. It was Murray himself who pressed the tape down into the hollow of the back. This means the tape was pressed to the body at three points. Almost a measurement taken 'between pegs', but not quite.

The method used in India, Nepal and Russia today is different. Ullas Karanth, Sunquist and Miquelle all wrote a tiger is measured along the contours of the spine. This only is possible when the tape is pressed to the body (the spine) at all points. A measurement taken in this way requires different people and a lot of accuracy. 

A century ago, in northern India, tigers were measured in exactly the same way (see the part in green): 

*This image is copyright of its original author

 

2 - THE DIFFERENCE BETWEEN A MEASUREMENT TAKEN 'OVER CURVES' AND A MEASUREMENT TAKEN 'BETWEEN PEGS' A CENTURY AGO

The conclusion is the method used in northern India was no different from the method used today. In northern India, the measurement was " ... carried out with extreme accuracy before the tiger was padded ... " ('Jungle Trails in Northern India', Sir John Hewett, 1938, pp. 67). Judging from the information offered by Sunquist, a tiger today also is measured with care. This means the result of a measurement taken in this way a century ago has to compare to the result of a measurement taken in this way today.

As for the difference between a measurement taken 'over curves' and a measurement taken 'between pegs'. Here's Hewett again (it is about the part in dark purple on the left page):

*This image is copyright of its original author

3 - THE DIFFERENCE BETWEEN A MEASUREMENT TAKEN 'OVER CURVES' AND ONE TAKEN 'BETWEEN PEGS' TODAY

Hewett and others familiar with both methods concluded " ... that the measurement by the two systems has differed from two to as much as five inches ... " ('Jungle Trails in Northern India', Sir John Hewett, 1938, pp. 68). Two inches is 5,08 cm. and five inches is 12,70 cm. 

Can we assume it was two inches in a small tigress and five in a large male? No. Hewett didn't write the average difference between both methods in large male tigers was 5 inches. He wrote that the measurements by the two systems differed to " ... as much as five inches ... " (see the quote above). This means that the difference was five inches in some cases and not in others. In his book, Dunbar Brander confirmed the difference between both methods was 3-5 inches. This means Hewett's longest male tigers most probably slightly exceeded 10 feet 'between pegs' in total length.

Can we apply this result everywhere regarding measurements taken 'over curves'? No. In Cooch Behar, the Duars and Assam, also a century ago, some males were measured in both ways as well. The average difference was 5,45 inches (13,84 cm.). In the longest tiger (10.5 or 317,50 cm.), however, the difference was 7 inches (17,78 cm.).

Two more examples. The male Amur tiger V. Mazak's measured in the Prague zoo was 319 cm. in total length when measured 'between pegs' and 337 cm. when measured 'over curves'. A difference of 18 cm. The male Amur tiger I measured was 298 cm. in total length when measured 'between pegs' and 312 cm. in total length when measured 'over curves'. A difference of 14 cm.

Why the significant differences in result? The main reason is the method used can be applied in different ways. Hewett wrote a measurement was " ... a matter of some ceremony ... " (see the first scan). If time was invested, the result was accuracy. In other regions, however, things might have been different. Maybe they didn't have the opportunity to invest time in a measurement. Maybe there were more tigers in a beat and maybe they had to go back to camp in time. Maybe those who measured tigers didn't have the experience needed. There are many reasons.  


4 - CONCLUSIONS SO FAR

a - The method used to measure tigers today is very similar to the method used a century ago in northern India.

b - For this reason, the results can be compared.

c - The difference between a measurement taken 'between pegs' and one taken 'over curves' ranged between 2-5 inches a century ago. In northern India, not in other regions. I opted for northern India as the standard for the reasons stated above.

d - In large male tigers, the difference between a measurement taken 'between pegs' and one taken 'over curves' could be as much as five inches. This, however, doesn't mean that the average difference was five inches.      


5 - ADDITIONAL INFORMATION

Anything else before we start 'translating' the results of measurements in India, Nepal and Russia today into the most likely results of measurements taken 'between pegs'? Yes. 

a - The emails of Miquelle and Sunquist

We have to consider the emails of Miquelle and, in particular, Sunquist. Both wrote that the body of the tiger is stretched before he is measured (a), thus reducing the number of curves. Sunquist also wrote that the skull was raised, in this way creating a more or less horizontal line between the skull, the spine and the end of the tail (b).

Was this not done in northern India a century ago then? Hewett wrote that a tiger had to be stretched before he was measured 'between pegs' (see the first scan above). There's no reason to assume that tigers were not stretched before they were measured 'over curves', as this is needed in order to get to an accurate measurement. And accurate it was. This is why the difference between both methods was very limited in northern India. I would get to a 'yes' for now.

Sunquist's emails suggest that measurements in Nepal were taken with great care. In his opinion, the results more or less compared to the results of measurement taken 'between pegs'. Based on his descriptions, I tend to agree. As tigers in India, Nepal and Russia today are measured in the same way, it is likely the results of measurements compare. However, the problem is this method can be applied in slightly different ways. Maybe Sunquist pressed the tape at some points of the body only, whereas those who measured tigers in Russia, as Miquelle wrote, might have pressed the tape at all points (see the photograph you posted). We don't know.


b - My experience  

In order to get to an answer, I reread the notes I made after I had measured captive big cats some years ago. All were measured 'between pegs'. Three big cats, however, were measured both 'between pegs' and 'over curves'. 

I also used another method. One could say it was 'discovered' quite by accident when I tried to measure the male Amur tiger 'over curves'. It wasn't easy. Different people are needed to do it right and even then it's very easy to skip or add a few curves on the way. I noticed I tended to skip a few more often than not. Then it was the turn of the others. I noticed they too struggled. I also noticed the results were very different. The reason is this method can be applied in different ways. One needs to be very concentrated and consistent. 

I noticed most of us made similar mistakes. In this respect, everyone was consistent. Same for the results. This is the reason I decided to measure the tiger in this way too. The results were recorded and the conclusion was this method nearly always yielded very similar results.   

And what was the name of this method? There was and is no name, but I can describe how it was applied. The tiger was stretched and the skull was raised. Then the (steel) tape was pressed to the tip of the nose, the top of the skull, the tip of the shoulder, the insertion of the tail and, finally, the last bone of the tail. The distance between these points was measured in a straight line, but one has to remember a number of angles were created by pressing the tape to the body at the points mentioned. This is why the cats measured in this way were longer than when measured 'between pegs'.   

Why did the attempts the measure the male Amur tiger in this way yielded very similar results? The reason was the method was easier to understand and easier to apply. It also didn't take a long time to measure the tiger. I wrote it would make sense to use this method instead of the other ('over curves'), because it was easier to use. This is important when time is a factor. 

In the way described above, a few curves were created. These, of course, resulted in a longer cat. I repeated the procedure three times and the results, not surprisingly (as this method is easier to apply), were quite similar: the total length was increased by about 3 inches. This was a long male tiger (he was 298 cm. 'between pegs' and 312 cm. 'over curves'), but some captive male Amur tigers can be longer. When measured 'between pegs', the longest can reach a total length between 10.6 (V. Mazak's Prague zoo male Amur tiger was just shy of 10.6) and 10.10. The Sungari River Amur tiger could have been about 10.10 'between pegs'. 

Why did I never inform our readers about this method and the results? The answer is simple in that it is not an accepted method. I thought I was the first to discover it, but apparently I was wrong. Murray's method was quite close and Sunquist's method also wasn't much different.

As the method described by Sunquist is a standard method used in India, Nepal and Russia, it means I should be able to say to what degree the result of a measurement taken in this way differs from a measurement taken 'between pegs'. The male Amur tiger of 298 cm. (when measured 'between pegs') was 3 inches longer when he was measured in the way described above. In a shortish male lion also measured in this way, the difference was 2 inches. But in a long tiger, the difference could have been 4 inches. 

In my long post on methods mentioned above, I proposed to deduct 1-3 inches from the measurements taken in India, Nepal and Russia. After reading my notes on the captive big cats I measured, I would increase the range to 1-3 inches in females and 2-4 inches in males. In very muscular or very long big cats, the difference could be 4-5 inches or even a bit more. 


6 - THE TOTAL LENGTH OF TODAY'S WILD TIGERS MEASURED 'BETWEEN PEGS' (proposal)

So how long are today's tigers in India, Nepal and Russia when they would have been measured 'between pegs'?

My proposal is to deduct 4 inches for males and 3 inches for females in India and Russia. This means that the total length of males in Nagarahole, when measured 'between pegs', could have been close to 9.5 (287,02 cm.). In Russia, it might have been an inch less (284,48 cm.). For Nepal, where the method described above could have been applied in a slightly different way, I propose to deduct 3 inches for males and 2 inches for females. 

My proposal regarding the adjustment, as you no doubt noticed, was adapted. In my long post in the thread on methods and measurements I proposed 1-3 inches, whereas it is a bit more in this post. The reason is my notes on the new method I recently read. This resulted in slightly different conclusions. 

There's also something else to consider. We run a forum. This means we don't want to misinform the public. The size of wild big cats, as Lt.-Col. Stevenson-Hamilton wrote in his book 'Wildlife in South Africa' (J. Stevenson-Hamilton - I have the Panther edition of 1957 - pp. 148), often is exaggerated. I agree. One has to see a big cat of 9 feet and 400 pounds up close to appreciate its size. 

In spite of deduction of 4 inches, there's no question that male tigers in Nagarahole (9.5 or 287,02 cm. 'between pegs' and 480 pounds or 217 kg. adjusted), Royal Chitwan (at least 9.5 and 488 pounds or 221 kg. adjusted) and Sichote-Alin (9.4 or 284,84 cm. 'between pegs' and 425 pounds or 192,5 kg.) are large animals. At the level of averages, Indian and, especially, Nepal tigers most probably are the largest wild big cats today.

Maybe they are a bit longer than suggested, but we don't know. At least, I do not. The reason is the method used today can be applied in slightly different ways. This means it is likely that different people measuring the same tiger will get to different results. It also means the results of this method have to be taken with care. Finally, we don't know how the result of a measurement taken in this way compares to the result of a measurement taken 'between pegs'. There's just too much room for interpretations.         

Also remember the samples were small in all three regions. Maybe Nagarahole and Nepal tigers are a bit smaller and maybe Amur tigers are a bit larger than we think. Krechmar thinks Russia still has very large tigers and he should know.   


7 - THREE TABLES ON THE LENGTH OF WILD MALE INDIAN TIGERS MEASURED 'OVER CURVES' A CENTURY AGO

In order to be as complete as possible, the post is concluded with three tables also posted in the thread on methods and measurements. This will allow those interested to get to a few conclusions on the length and weight of Indian tigers then (a century ago) and now.  


a - Northern India and Nepal

The tigers actually weighed averaged 291,96 cm. (about 9.7). Those not weighed averaged 300,87 cm. (9.10 and a half). Five Nepal male tigers shot in an unmolested region averaged 311,15 cm. (almost 10.3). Those weighed averaged 435,90 pounds and 291,86 cm. in total length 'over curves'. Based on the difference between those over 440 pounds and those that fell short of that mark, I decided for a few extrapolations. The result was an average of 480-490 pounds for all adult male tigers in this region. More than a century later, the adjusted average for 7 males in Royal Chitwan was 488 pounds. The conclusion is there is no significant difference between then and now in northern India and Nepal:      

*This image is copyright of its original author

b - Cooch Behar, the Duars and Assam

The Maharajah of Cooch Behar provided the best data ever on wild tigers. His sample also is quite large.

As for the results. The male tigers actually weighed were a bit longer than those weighed in northern India and Nepal. They also were heavier. This, again, suggests a strong correlation between total length and weight in male tigers in India. For additional confirmation, have a look at those over 440 pounds and those below that mark. The conclusion is longer tigers were significantly heavier.   

Were Cooch Behar tigers larger than those in northern India? No. They were a bit (about 4 cm.) shorter. If all tigers in the table on northern India would have been weighed, the average would have been 480-490 pounds, as opposed to less than 460 (say 450-460) for Cooch Behar. 

Here's the table on Cooch Behar tigers:                          

   

*This image is copyright of its original author

c - Northwest India, Nepal, Assam and the Deccan compared

The Deccan sample is both small and very old (an century and a half). Deccan tigers were a trifle shorter and not as heavy as those just south of the Himalayas. But they too show a remarkable difference between heavy tigers and others. Those over 420 pounds were about 5 inches longer and 63 pounds heavier than others. Same as in tigers in northern India but a bit less outspoken, which most probably is a result of their smaller size.

One of those who hunted in the Deccan (Brig.-Gen. R.G. Burton) wrote different books about his experiences. His longest tiger, a very heavy male (well over 500 pounds), taped 9.8 'between pegs'. He didn't believe in 10-footers, but he was wrong. In central and northern India, they were seen and shot every now and then. Same for Nilgiris, south of the Deccan. I think the general selected one of the regions were tigers were a bit smaller. Bad luck. 

Nagarahole tigers, by the way, were quite large animals, then and now. This is a tiger known as 'Old One Eye'. He was shot in the Nilgiris and taped 11 feet 'over curves'. Estimated weight 700 pounds. But in this case a severe adjustment would not have been entirely out of place:

*This image is copyright of its original author

Here's the table on northern India, Cooch Behar and the Deccan:   

   

*This image is copyright of its original author

  


8 - CONCLUSIONS

a - The method used to measure tigers today is very similar to the method used a century ago in northern India ('over curves'). My guess is the results of the measurements can be compared.

b - In northern India, those familiar with both methods ('over curves' and 'between pegs') concluded the difference between both methods ranged between 2-5 inches. Although it is more than likely that the difference was more outspoken in long tigers (males), the average difference is unclear. 

c - Does this mean one has to deduct 2-5 inches from the length of today's tigers (2 for females and 5 for males) in order to get to the length measured 'between pegs'? My guess is no. The main reason is in the detailed emails of Sunquist. He wrote the result of a measurement taken in the way he described would almost compare to the result of a measurement taken 'between pegs'. My guess is he could be close. I measured a large male Amur tiger in three different ways. When measured 'between pegs', he was 298 cm. in total length (head and body length 194 cm.). When measured 'over curves', he was 312 cm. When measured in the way described by Sunquist, he was 305-306 cm. (about 3 inches longer than when measured 'between pegs'). Based on this, one could make a case for an average difference of 3 inches in a male tiger similar in length to those measured in India, Nepal and Russia.  

On the other hand. It isn't clear if the method described by Sunquist was used in the same way in India and Russia. It seems likely (Ullas Karanth wrote the method used in these regions is a standard method), but we are not quite sure. Furthermore, one has to remember that tigers in Russia, Chitwan and India are large animals, with males not seldom exceeding 9.6 (289,58 cm.) in total length (measured 'between pegs'). Although this means that the average difference between a measurement taken 'between pegs' and a measurement taken in the way described by Sunquist most likely is close to 3 inches in males, we want to prevent misinforming the public. For these reasons, I propose to deduct not 3, but 4 inches for males (3 inches for females) in Russia and India and 3 inches for males in Nepal (2 for females). This means that male tigers in Russia and India most probably average 9.4-9.5 in total length 'between pegs'. Nepal tigers could be a bit longer. 

d - There's no question that male tigers in India (480 pounds adjusted) and Nepal (488 pounds adjusted) are heavier than in Russia (420-430 pounds not adjusted, but nearly all males captured were empty or close to empty). As the difference in weight can't be explained by a difference in total length, there has to be another reason. The most likely reason is a low prey base. Another reason could be the lack of large herbivores. One also has to consider climate and the large number of hunters (about 60 000) in the Russian Far East.    

e - The samples in Nagarahole, Royal Chitwan and Sichote-Alin were smallish. Furthermore, the Russian sample had a number of 3-year old male tigers and 'problem tigers'. This means the results of the measurements have to be taken with care.

f - Compared to male lions of large subspecies, male tigers in Russia, Nepal and India are a bit longer (4-6 inches in total length). Nepal and Indian tigers also are heavier (about 50-60 pounds). Amur tigers and lions in South Africa, however, seem to be about similar in weight. One could argue that there is no information on Nogorogoro lions, but those who do should add there also is no information on tigers in Kazirangha. Exceptional individuals of both species seem to be quite close in head and body length and, perhaps, weight, but those interested in details would no doubt say that 'quite close' is different from equal. The main difference between both species is tigers produce more exceptional individuals. This although the number of wild tigers is about 10% of the number of wild lions. Compared to tigers of large subspecies, lions are as tall or (relatively) taller. They also have longer skulls.        

g - Wild tigers have been walking the edge for quite some time now. Unfortunately, some of them (including the Sauraha tiger in Nepal) perished when they were captured for research. Although these freak accidents were few and far between, every individual counts. As it is likely that less tigers will be captured in the near future, new information on the size of wild tigers will be limited. This means we have no other option but to use the familiar data time and again. Although chances are the information we have is not representative (many samples are small), my guess is that the trends will be confirmed. Reply