A Discussion on the Reliability of Hunting Records

[WaveRiders]

Pckts


A few comments on your remarks of my post to get to conclusions from my side.

 

Pckts wrote:

“I have a bit of a disagreement with this, how can you assume that all tigers hunted were of the larger size?

To me it makes no sense, once you have a couple of "hunting seasons" the dominate males would most likely be removed. They are the most bold and their territories must be patrolled making their patterns more predictable. After a few seasons you would essentially remove all the dominate males and no longer have any full grown males to impress others.
Essentially, any area hunted can only provide a small % of large males, after that, you will be hunting females, sub adults and the elderly.”

The Maharajah Juddha Shamsher Jang Bahadur Rana ruled from from 1 September 1932, when 57 years old, to 29 November 1945. His hunting feasts are narrated by Smythies (1942) starting from January 1933, four months after he became the Prime Minister of Nepal (I remind that Nepal was a kingdom till 2008, but the King counted nothing and basically lived imprisoned in his palace since 1846 when the Rana family took power till 1951 when King Tribhuvan was able to escape to India and helped by the newly established Indian government disposed and exiled the Rana family).

His predecessor Bhim Shumsher Jung Bahadur Rana ruled from 26 November 1929 to 1 September 1932 taking power when 64 year old. The predecessor of Maharajah Bhim, Chandra Shumsher Jung Bahadur Rana ruled Nepal from 27 June 1901 to 26 November 1929 when he died at the age of 66 years.

For sure Maharajah Chandra loved hunting a lot, not so sure, although presumably yes, about Maharajah Bhim. It could have happened that just in the years preceding 1933, tigers in most Nepalese jungles were not much disturbed if not nearly undisturbed.

If that was the case there is a realistic possibility that the 12 male tigers reported by Smythies (1942) shot in 1933 (9 ones in Chitawan) could have been somewhat selected by the Maharajah shikaris for large size (on average) and not only those ones. In my opinion this sounds logical: I am the just established Maharajah of Nepal since a couple of months, organize my first hunt as a Maharajah, I want to impress and all my shikaris, servants and entourage want me to impress to celebrate my greatness (see comments by Mishra, 2010). Add pristine jungles in Chitawan probably nearly undisturbed for years and the result is that selection for large size male tigers was favoured. Or you want me to believe that the Maharajah Juddha Rana of Nepal went in Chitawan for his first hunt  as a Maharajah after 4 months to shoot small tigers?

From Mishra (2010)

*This image is copyright of its original author

Note that the 8 male tigers shot between 14 January and 20 January 1933 in Chitawan measured between 3000 mm to 3277 mm in total length over curves, the last male shot in that hunt on 22 January 1933 in Chitawan measured 2845 mm, and the 3 ones shot elsewhere (in N. Muluk) on 24, 26 and 29 December 1933 measured 2743, 2819 and 2845 mm. I do not think it was any difficult to locate in the Chitawan ecosystem of the early 1930s encompassing a few thousands square kilometres less then a dozen adult male tigers larger then average to make the Maharajah more then happy for his first hunt as a Maharajah and everybody be rewarded.

Note that the 3rd male tiger shot by the Maharajah (the 6th tiger included females) is the one measuring 10 ft 9 inches (3277 mm) and allegedly scaling 705 lb (319.8 kg), a weight I am cautious to accept for a number of reasons I partly already explained.

No male tigers are reported by Smythies (1942) shot in Chitawan from 22nd January 1933 till 5th December 1938 (the 6 males shot in December 1938 ranged 3023 – 3251 mm) and in the last Chitawan hunt at the end of January – mid-February 1939 the 8 males shot ranged 3048 mm to 3251 mm.

All in all I believe there was plenty of room particularly, but not only, for the shikaris of the Maharajah of Nepal to select tigers for size larger then average. No doubt Nepal was a paradise for large tigers particularly before WW2.

Pckts wrote:

“So, I am all for using the un-adjusted weights for any cat, over subtracting an inconsistent poundage based on our own interpretations. If one wishes to note that the cat ate very recently or not, that is fine but it shouldn't automatically be used to subtract 30 kgs for every cat weighed or measured.”

If you want to inflate tiger weights significantly more then any other big cats you can do it, but your results, comparisons and conclusions will be incorrect.

Non-adjusted scale weights of Bengal tigers from hunting records as well as from modern zoological studies (at least those of Chitawan tigers, those of Nagarahole tigers and Madla male from Panna) are clearly more inflated upwards on average due to stomach contents then for any other big cats species sample. We know the reason for it (tigers very often baited or located close to a large kill).

Karanth adjusted the weights of the adult male tigers he weighed in Nagarahole NP, India, by nearly 29 kg on average for good reasons. These adjustment have been made for each single individuals (21 kg, 30 kg and 35 kg) based on his experience. If you want to question his experience, this is another story and your problem. Adjustments by authorities with huge field experience are not made randomly. They are based on quite solid background. For lions Bertram (1975) established a belly size index. This “belly size scale” has been used for decades till nowadays by professional zoologists.

When I talked / talk about adjusting weights I have nearly invariably primarily talked of adjustments on the average weight of samples and not on the weight of single individuals. In a sample of adult male tigers much prevalently baited my best estimates generally range within 14-20 kg, not your alleged 30 kg. Concerning single individuals with no detailed information I agree it can be incorrect if not even pure speculation, but assuming the heaviest individuals in particular, but not only,  were most likely at empty stomach or close is foolish in principle.

 

In my previous post I reported the following excerpt from Corbett (1944)

“Wyndham, you will remember, said the tiger was ten feet between pegs, which would give roughly 10' 6" over curves; and while one shikari said he was 10' 5" over curves, the other said he was 10' 6" or a little more. Shot seven years after these estimates were made, my sister and I measured the tiger as being 10' 7" over curves."

Pckts wrote:

“A tiger can grow quite a bit in 7 years.”

Any possible growth of the Bachelor in those 7 years has no relationship with the sentence I put in bold black (now underlined) and related to the contest I wanted to highlight: you only need to read “Wyndham, you will remember, said the tiger was ten feet between pegs, which would give roughly 10' 6" over curves”.

 

Pckts wrote:

“There are 7 billion people in this world, probably 1% are over 7' and less than that have reached 7.5' or more. Just because these "freak" specimens don't occur in bulk they still occur. A 700lb tiger is certainly not some mythical weight for an animal that averages 470lbs, its very possible and has occurred already. Whether you're willing to accept that or not is a different story.”

1% of world population (including children, females and elder people) over 7'? Over 70 millions (EDITED) people over 213 cm high? Where do you live?

I also believe you should deeper reflect on the fundamental difference between a freak human that can live with plenty of assistance and become a basket superstar with respect of a freak tiger that must still hunt by himself and eat within quite a difficult environment and mostly nimble preys. In the wild if you do not fit your requests you die.

Should I have time I may post at some point in Carnivora a detailed probabilistic calculation of weights and lengths and how it reflects in the population and any subpopulations of tigers, lions, brown bears and possibly other species of animals. It is not difficult to make such kind of estimates.

For now I can anticipate you that in the last 200 years since the very beginning of the 1800s I estimate less then 4-6 millions wild tigers in the whole of Asia reached subadulthood and adulthood including males and females. This would translate in less then one million adult male tigers of the 4 largest subspecies to be existed in the last 200 years, meaning no more then half a million in India, Nepal, Bhutan and Bangladesh.

Based on historical records pre-1970s and under a few straightforward sensible statistical assumptions I estimate the most likely theoretical probability of occurrence of an adult male Bengal tiger measuring 11 ft in total length over curves (properly measured) at one animal every 120-200 adult males (not including Sunderbands and Naga Hills). This probability is low although still quite realistic and can raise some excitement if not knowing some basic concepts of statistics and probabilistic calculation in mathematics: the theoretical probability I can compute drops to one animal of 11 ft 6 inches every 3500-7000 adult male Bengal tigers. Guess how much would be the theoretical probability of an animal of 12 ft? One every some 300000-800000 (300-800 thousands), which probably cover more then all Bengal, Amur, Caspian and Indochinese wild adult males existed in the last 200 years. And one Bengal adult male tiger measuring 12 ft 6 inches in total lengths over curves (properly measured)? One every some 50-300 millions, clearly statistically meaning that such a tiger did theoretically not even exist during the whole of the 10000 years of Holocene anywhere. If I have to add any comments, in my opinion all the above indicative theoretical probabilities are if anything likely even optimistic.

Based on ecological and biomechanical constraints the reality is that I believe a 11 ft 6 inches over curves wild tiger has a very much unlikely / non-realistic probability to have existed in Holocene (when properly measured in the flesh as they laid according to the methods of the Maharajah of Cooch Behar, Corbett, Hewett, Brander, Stockley, Champion and so on) if not under an exceptional combination of an absolutely extremely long head-and-body such as the one of the Brander’s largest tiger (theoretical probability 1 individual every ca. 700 to over 25000 adult males) and an exceptionally long tail. No reliable reports of such a combination exist to my knowledge.

You may know about the Vietnamese monster tiger shot by Baze weighing 570 lb (258.5 kg) and measuring over curves 11 ft 6 inches (3505 mm) in total length, 7 ft 2 inches (2184 mm) in head-and-body and 4 ft 4 inches (1321 mm) in the tail. As I do know that a few other very large Vietnam tigers have been reliably and accurately measured (the largest from White measuring 10 ft 7 inches, 3226 mm, in total length over curves with a massive skull given at 15.5 x 11.5 inches, 393.7 x 292.1 mm), I am inclined to consider and have always considered in principle acceptable the head-and-body length of the largest Baze tiger. As far as the total length and tail length are concerned I do believe that accepting these figures would include in the statistics a clearly spurious data. Which other tail comes just reasonable close to such a tail length? Absolutely nothing. Again I can suggest that on the basis of existing hunting records in which tail lengths appear generally significantly shorter then what modern scientists are measuring on wild tigers of equivalent size (I already highlighted this issue of much likely inconsistent tail root definition last year in Carnivora forum and likely elsewhere previously), the probability of occurrence of a tail measuring at least 1321 mm in a tiger population of Bengal tiger body size is one every some 500000000 (five hundred millions) adult males. My conclusion on the tail and consequently the total length of the largest Baze tiger? Inevitably rejected also because the probability would still be as low as 1 every some 4 millions or so adult males on the basis of Bengal tiger tail lengths measured by modern scientists (significantly longer).

I give you some more headaches.

Based on (non-adjusted) historical weight records pre-1970s I estimate the theoretical probability of an adult male Bengal tiger weighing 705 lb (319.8 kg) non-adjusted to be one animal every approximately 20000 (twenty thousands) adult males. Assuming in the early XX century there were 50000 Bengal tigers in India, Nepal, Bhutan, and Bangladesh, there were no more then approximately 7000-10000 adult males at any time, meaning that there could have been one 705 lb non-adjusted adult male Bengal tiger living for one year every approximately 2-3 years on average. If one limits the calculation to North India and Nepal the theoretical probability raises to one animal every approximately 7000 adult males, but the population number approximately halves or more. In Central India the theoretical probability drops to one every some half a million and in Southern India even quite less then that. I believe such an unbalance was unlikely and it is possible that the probability in North India and Nepal could actually be lower while the ones in Central and Southern India higher. You may like to know how much is the theoretical probability of occurrence of the weight of the wild tiger shot by D. Hasinger allegedly claimed 857 lb (388.7 kg) non-adjusted? One animal every at least one billion and more then likely a few billions adult male Bengal tigers!

Let’s assume that the average amount of stomach contents in historical adult male Bengal tiger records pre-1970 is 6% of the empty stomach average weight or some 11-12 kg (my average non-adjusted weight of adult male Bengal tigers Naga hills and Sunderbands excluded is quite consistent to that suggested by GuateGojira at 204 kg). Let’s also assume the exceptionally big 705 lb tiger shot by the Maharajah of Nepal was fully gorged with 40 kg of meat in the stomach and the supposed hyper-gigantic Hasinger tiger with 50 kg of meat. Under this scenario the probability of occurrence in the old days of a nearly 280 kg tiger at empty stomach would be 1 animal every somewhat over 1000 adult males, while the one for a nearly 340 kg tiger at empty stomach would still be as low as one every approximately 10 millions adult males!

One may also argue to narrow the probabilistic calculation to the Bengal tiger subpopulations of presumed largest/heaviest body size (for instance grouping together North India and Nepal as I briefly shown for one example). I also made this calculations and the theoretical probabilities of occurrence of extremely large / heavy animals in some cases raise, but not always when data are quite less spread in a smaller sample in spite of a higher average, actually reducing the probability of occurrence. Furthermore the smaller population number implicates at the end the actual occurrences may not markedly change within a more limited number of individuals.

Bear in mind that my probability calculations could inevitably be somewhat revisited as dealing with tiny fractional probabilities within an inconsistent, non-homogeneous and possibly not particular accurate and reliable sample is difficult. However I believe any re-computation would not affect the qualitative meaning of the results and the conclusions one can extract.

 Pckts wrote:
 
“I see nothing you posted that would back this claim.”
 
You should reflect a bit more on the percentages I calculated of the tigers whose measurements have been reported by the Maharajah of Cooch Behar (1893, 1908), Hewett (1938) and Smythies (1942) compared to the total tigers shot/seen shot by each of them.
 
 
Pckts wrote:
 
“The reason one might consider this is due to your history, the scrutiny you put on these measurements would be fine if you put the same scrutiny to lions. From what I see, you never question a lion weight or length, never dive into what should be considered valid and who nor do you ever question the hunters of them.
At least from what I have seen that is.”
 
What do you want me to question about morphological or ecological data of lions, bears or other animals? Feel free to ask. Did I state something somewhat unrealistic on lions, bears or other animals? Feel free to let me notice that. The only major topic I cannot discuss in details is the Ngorongoro Crater lions body size (chest girth) and estimated weight and I already explained why several times: virtually all data (chest girths) are unpublished and I cannot release those info and data I have in my possession. However Dr. Packer qualitatively already stated quite a lot and it is not difficult to get to some qualitative conclusions.


Pckts wrote:
 
“Many captive big cats weigh right in the prime range of their wild counterparts. You should know as well as anyone, tigers and lions have a large variation of weights even with in the same territories.”
 
I meant another thing, which is myself wondering when a small child why I could not see anywhere a living tiger measuring any close to 4 meters. The answer is obvious.

 
                        WaveRiders

Reply