Who is the "king" of tigers? - Bengal or Amur

[GuateGojira]

Old vs New, what is the difference?
(Information updated with all the new modern measurements and weiights available)

Whit this new wave of information, we got a pretty decent sample for body meausrements from Bengal tigers in modern days. So, taking this oportunity I decided to make a comparative between the old measurements before 1970 and the new measurements taken by scientists after 1973. Here is the table:

*This image is copyright of its original author

Now, there are several points to analize here:

1 - The modern measurements are actually a mix of methods. Yes, we know that all were taken "over curves", but honestly that prase it tooooo wide and need especification. For example we know now that the tigers from Nepal were measured following an straight line (like if they were measured between pegs) according with Dr Sunquist and the single male from Tadoba was measured in the same form in front of cameras. Now, about the tigers from Nagarahole we still don't have confirmation, but knowing that Dr Karant worked with Dr Sunquist, we can guess that he used the same metod. Now, about the new tigers from Panna, there is still not a clear confirmation, and the picutres that I have from India shows that the measurements were taken in a form close to that of those from Nepal. But for the moment, I put in the notes that were taken "along the curves" and I leave it like that.

2 - These samples do not include Sundarbans, as most of the records are modern ones, so I try to kept the study only with mainland tigers for a fair comparison. Old records are only "between pegs", no over curves or skins were included at all.

3 - The sample of males from the old records was of 151 single males, three of them do not had tails. Now, the head-body sample included only 93 specimens. For females we have the same problem, a sample of 67 single females but only 28 had head-body lengthts. So, ir order to get a better frame of the real variation on this measurements, I used a sample of 82 males and 20 females and made a regression equation to check the relation between the head-body length and the total length. The results are these:

HB - TL in males: y = 0.7045x - 9.5526 - r=0.78
HB - TL in females: y = 0.5718x + 19.449 - r=0.79

As we can see, the correlation may not be perfect but is strong (over 0.5) so at some point is relliable to reconstruct the HB from the TL, so I done it with all the specimens and that is why the table above shows 151 specimens with HB length (3 of them do not had tails at all). The same with females. Now, about the tail, the correlation in males is weak (r=0.37) but is stronger in females (r=0.68). however, tails are not important in our analysis, so I just made it from the diference between the TL and HB. Incredible, the diference between the values obtained with subtraction and those from the equation was close to the 97%, so no big deal with tails. This sample do not include the specimens from Brander as he only presented the averages and not single values.

Now, this values as the close ones to a readl HB from all the sample, I will try to do this with the lions, specialy for South African population, as the HB of 191 cm "between pegs" is based only in the specimens with that particular measurements and exclude those that had only TL. So probably the value will be lower under this correction method.

4 - Modern specimens seems bigger overal than the old ones by an small margin. Under one perspective we could say that this is because the modern tigers were measured on the body and not with pegs, and that could be possible, however other posibility is the fact that modern records include only sexualy mature specimens from over 3 years old, while those from the hunting records include a pletora of specimens that were included as "adults" just because they looked big and that is something that I discussed before based in the statements of Brander himself and the measurements of juvenile tigesr from Nepal. That will explain also the higher weights.

I hope you like this comparative tables. And is insterting to see that in historic specimens, the Amur tiger surpass the Bengal tiger for more than 10 kg in males and is about the same in females.

5 - Finally, in the modern records, the maximum that I used was 261 kg because the average of 214 kg include specimens adjusted for stomach content. If I used the real values, included the two of 272+ kg for tigers M-105 and M-126, the average will be higher. 


I will like to read your opinions, suggestions and more information if you have.

Greetings to all. Reply