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

[peter]

TIGERS IN NORTHERN INDIA AND NEPAL - PART XVII


Nepal (males - d)


a - Overview of 66 male Nepal tigers shot and measured 1908-1939

In the previous posts on tigers in northern India and Nepal, I posted information on the length of 71 male tigers shot in Nepal:

- 6 shot by the Maharajah of Bikanir in 1920 (source: JBNHS, Vol. 27, 'A sporting diary', pp. 386-391);
- 5 shot by Sir John Hewett and his party 1908-1912 (source: 'Jungle trails in northern India', J. Hewett, Natraj Publishers reprint 2008, pp. 169-174);
- 8 shot by the party of Sir Harcourt Butler 1919 (source: 'Jungle trails of northern India', J. Hewett, Natraj Publishers reprint 2008, pp. 71, 174-175), and
- 52 shot by the Maharajah of Nepal and his guests (source: 'Big game shooting in Nepal', A.E. Smythies, 1942).

Of these 71, 5 were omitted. The reason is age in all cases. One of the 6 males shot by the party of the Maharajah of Bikanir was very old and much shorter than the others. One of the 5 males shot by Hewett's party, also quite a bit shorter than the others, most probably was immature. Same for 3 of the 52 males shot by the Maharajah of Nepal and his guests.

The 66 remaining male tigers, most probably, were adult when they were shot. Here's the table with the 66 male tigers shot in Nepal in the period 1908-1939 (from left to right: source - year of publication - year in which the tigers were shot - total length 'over curves' - weight and remarks):

Table XVII:

*This image is copyright of its original author

  
b - Remarks

1 - Sources

The first source is the article in the JBNHS. The article wasn't written by the Maharajah of Bikanir (who there when the tigers were shot and measured), but by those who had direct access to it. Secundary, but reliable. Method of measurement clear ('over curves'), but no details were offered on the way the method was applied. Secundary and moderately reliable.  

The second source is Hewett's book. The book is a prime source regarding the 5 tigers Hewett and his party shot. Hewett also offered details on how the method used to measure tigers ('over curves') was applied. Prime source and very reliable. 

As to the 8 male tigers shot by the party of Sir Harcourt Butler in 1919. The information on these tigers, as far as I know, is not based on a publication, but Hewett apparently had direct access to the source. There's no information on how the method used to measure the 8 tigers ('over curves') was applied, but Hewett thought the information was reliable. This is remarkable, as Hewett was quite sceptical of measurements (read his book). Secundary and moderately reliable. 

The third source is the book of Smythies ('Big game shooting in Nepal'). Smythies wasn't there when the tigers were shot and measured, but he had direct access to the source (the diary of the Maharajah of Nepal). Although there are no details on the method used to measure tigers ('over curves'), Smythies talked to the one who headed the team responsable for the measurements. All tigers were measured by one team. Smythies, more than once, underlined the measurements were reliable. This statement carries some weight, as Smythies had been a Forest Officer in India for most of his life. He also had hunted tigers and was familiar with the method used to measure tigers in northern India. Secundary, but reliable.                       

Although 2 of the 3 sources are secundary and although crucial information on how the method used to measure tigers was applied is missing, the measurements, in my opinion, can be considered as quite reliable. Not quite what we would have wanted, but this is about as good as it gets. And way too good to dismiss out of hand.

2 - Sample

The sample in the book of Smythies (n=23) is good enough, but the other samples are a bit wanting. In my opinion, the right order would be Smythies - Hewett a - JBNHS - Hewett b. The only region exceeding the threshold would be Chitawan.

It is, however, interesting that the sample of Sir Harcourt Butler (described as Hewett b above and samplewise considered as insufficient), averagewise, nicely compares to that in the book of Smythies. Why interesting?

Well, the tigers shot by party of Sir Harcourt Butler were shot in Chitawan as well. They averaged 306,06 cm. 'over curves' in total length (n=8) in 1919, whereas those shot by the Maharajah of Nepal and his guests, shot in the period 1933-1939, averaged 307,65 cm. 'over curves' in total length (n=23). How close can you get?

3 - Average total length 

In the period 1908-1939, the average total length 'over curves' of 66 males shot in different parts of Nepal was 303,04 cm. or just over 9.11 (range 9.0 - 10.9). In central parts of Nepal (Chitawan), the average of 2 samples was 306,06 cm. (n=8) and 307,65 cm. (n=23). These averages, as far as I know, are unsurpassed. There's no question that Nepal tigers are longer than anywhere else.

The Nepal tigers in the table above were measured 'over curves'. I also have records of Nepal male tigers measured 'between pegs'. The difference between both methods, as was discussed before (see the previous posts), was 2-5 inches in males in northwestern India (Hewett, 1938) and 5,45 inches in males in northeastern India (the Maharajah of Cooch Behar, 1908). After reading everything I have, I concluded it's likely that the way the method was applied in Nepal compared to the way the method was applied in northwestern India. This means we should deduct 2-5 inches in male tigers in order to get to the total length 'between pegs'. For now, I propose to deduct 2-3 inches in short males and 4-5, maybe 6, in long males. This would result in an average of about 9.6 'between pegs', maybe a bit more (range 8.9 - 10.3 or 8.10-10.4). If we decide for a total length of 285-290 cm. 'between pegs' (most probably closer to 290 cm. or even just over), chances are we would be very close to the mark.        

Confirmed in Nepal tigers measured 'between pegs' in those days (1900-1940 roughly)? Yes. The average total length 'between pegs' I found is very close to the average calculated above (range 9.4 to just over 10.0).  

4 - Weight

There's not much on Nepal tigers. What we have, however, strongly suggests that the average for males in Nepal is well over the average calculated for northwestern India. For that region, I got to about 475 lbs. some years ago. If we assume that the correlation between total length and weight in Nepal male tigers is similar to the correlation found in males in northwestern India (likely, as both inhabit the same region), Nepal male tigers should be heavier. Some years ago, I got to 480-500 lbs. (empty). Hewett's data fit perfectly. Same for the males weighed in Chitawan many years later. They averaged 488 lbs. adjusted and 520 lbs. unadjusted.

One of the males (the Sauraha tiger), at 10.2 in total length 'over curves' (and most probably very close to 10.0 'between pegs' if we consider the description of Sunquist on the way the method was applied), bottomed a 500-pound scale when he was first weighed as an adult. Some time later, he bottomed a 600-pound scale. A few years later, another Nepal male tiger weighed by researchers also bottomed a 600-pound scale:

" ... The high productivity of the riverine systems of the Terai may also be responsible for notable characteristics of the local tiger population. For example, Sunquist, Karanth, and Sunquist (1999) have noted that tigers in Chitwan have the smallest home ranges and highest densities in Asia. Male tigers (figure 3.6) captured in Chitwan are also the largest free-ranging Panthera tigris captured to date. Both a male captured by Smithsonian and Nepalese researchers in 1980 (tiger M105) and another captured by our project in 1984 (M026) exceeded 270 kg. 

Amur tigers of the Russian Far East are reported to be the largest in body mass among tiger populations spread across Asia. However, no male Amur tigers captured to date have exceeded the records of body mass reported for Chitwan (Dale Miquelle, personal communication, 1999) ... " ('The return of the unicorns', E. Dinerstein, New York, 2003, pp. 44).

The heaviest wild male Amur tiger weighed by researchers was a young adult male. Although a bit shorter than average, he was 212 kg. (468 lbs.). Some others ranged between 200-207 kg. (442-458 lbs.). The average of those weighed in the last decades is about 190 kg. (420 lbs.), but Miquelle thinks an average male is about 430 lbs. (195 kg.).  

The heaviest wild Amur tiger accepted by researchers, at 560 lbs. (254 kg.), is a male shot by Baikov near the Korean border more than a century ago. The Jankowski's, however, shot (and photographed) a male of 11.6 'over curves' in total length in July 1943 near the Sungari river in Manchuria (China). This tiger was estimated at about 300 kg. (662 lbs.). Although he, according to W.J. Jankowski, who corresponded with V. Mazak, had killed and eaten a large male brown bear a few days before he was shot ('Der Tiger', V. Mazak, 1983, pp. 188-189), there are more reports about wild Amur tigers well exceeding 300 kg. At least 3 of these ranged between 340-384 kg. ('Der Tiger', 1983, pp. 189). Although not one was accepted, authorities agree that wild Amur tigers were heavier in the recent past.

Captive Amur tigers, perhaps, reflect the potential. Some members of forums posted tables with records of captive males. The averages they found ranged between 210-220 kg. (464-484 lbs.), very close to the historical average of wild male Amur tigers.      
   
The decline in size most probably is a result of a combination of habitat destruction, prey depletion and hunting. Less than a century ago (between 1900-1940 roughly), Amur tigers walked the edge. The, atypical, lack of individual variation in Amur tigers could be a result of the population bottleneck they faced in that period. Without Kaplanov, who rang the bell, Amur tigers most probably would have been exterminated.     


c - Conclusions

1 - In the period 1900-1940, 66 male Nepal tigers averaged 303,04 cm. in total length measured 'over curves'. Chitawan male tigers were even longer. The 8 males shot by the party of Sir Harcourt Butler in 1919 averaged 306,06 cm. in total length 'over curves', whereas the 23 males shot by the Maharajah and his guests in the period 1933-1939 averaged 307,65 cm. in total length 'over curves'. The averages for male tigers in Nepal in general and Chitawan in particular are unsurpassed. 

2 - Although the information on the length of Nepal tigers in this post, apart from a few exceptions, is not based on undisputed prime sources, it is considered quite reliable. One could say this conclusion was confirmed by researchers working in Chitawan.           

3 - In the period 1900-1940, as far as I know, only 4 Nepal male tigers have been weighed. One of these, most probably an immature male shot in 1909, was 368 lbs. The longest shot by the Maharajah of Nepal in 1936, at 10.9 'over curves' in total length, was 705 lbs. The other 2, shot in 1909 and 1910, were 487 lbs. (total length 'over curves' 292,10 cm.) and 488 lbs. (total length 'over curves' 302,26 cm.) respectively. If we remove the immature male and the giant shot by the Maharajah, the average of 2 is 487,5 lbs. If we include the 2 others, the average is 512 lbs. (range 368 - 705).  

4 - What to say on weight? In order to get to an answer, we have to do a detour. I propose to go to northwestern India first. 

In the period 1907-1912, Sir John Hewett weighed 15 male tigers shot in northwestern India. They averaged 433,27 lbs. (range 355-570). Of these 15, one male of 366 lbs. had been quite severely wounded some time before he was shot. Another male of 355 lbs. was not quite adult when he was shot. Without these 2, the average of the remaining 13 was 444,46 lbs. The males weighed, however, were quite a bit shorter (292,606 cm. in total length 'over curves') than those not weighed (they averaged just over 300 cm. in total length). Many of those not weighed were described as 'heavy' or 'very heavy'.

I tried to get to an average of those not weighed by using the details of those weighed. The result was then added to the total of those actually weighed. The average of different attempts ranged between 460-490 lbs. for all males shot in northwestern India in the period 1883-1927. As a hypothesis for now, I propose to take 475.

Nepal male tigers are about 2 inches longer than male tigers in northwestern India. Using the same method as described above, I tried to get to an average for Nepal. Most attempts ranged between 480-500 lbs. For now, I propose to take 490.

Is there any way to reject or confirm the proposals regarding average weight of male tigers in northwestern India and Nepal? The answer is no regarding northwestern India and yes, to a degree, regarding Nepal.

In the last decades of the last century, there have been different projects in Nepal. As far as I know, research in Chitawan still is ungoing. What do we know? Well, Chitawan males averaged 488 lbs. adjusted and 520 lbs. unadjusted. All in all, less than 10 males were actually weighed. Of these, 2 bottomed a 600-pound scale. One of the 2, at 10.2 'over curves' in total length, was adjusted to 261 kg. (576 lbs.). This weight was a result of regression. A bit tentative, I think. There are no details about the other male (M026).

All in all, I think the proposal regarding weight in Nepal was confirmed. You could decide to follow Kitchener and go for unreliable because of a lack of adjustment (which in fact is incorrect) and you could opt for another conclusion. Up to you.

5 - There's no doubt that that Nepal male tigers in general (at the level of averages), and those in Chitwan in particular, are the longest and heaviest wild big cats today. I'm not sure about the situation a century ago, because those in the know agree that wild Amur tigers were larger than today's wild Amur tigers. They might have compared to Chitawan male tigers, that is. Chitawan tigers apparently didn't change a lot in a century and there's no reason to assume that Amur tigers would be different. Chitawan, however, didn't change a lot. Not true for Sichote-Alin.    

6 - As to the maximum weight of wild lions and tigers. There's, I think, no question that some of today's male lions ranged between 260-280 kg. One of these, a male of 260 kg, was about 240 kg. adjusted. Not sure about the 2 others. There's also no question that some wild male tigers compared or even slightly exceeded that mark (referring to the 705-lbs. Nepal tiger shot by the Maharajah of Nepal and 'Old One Eye' shot in southwestern India almost a century ago (that tiger was 11.0 'over curves'). The difference is wild tigers in Nepal (and India) seem to do it more often. This although the number of wild tigers In India and Nepal is well below 2500 (about 200 in Nepal and just over 2000 in India). Reply