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

[peter]

(06-01-2017, 09:49 PM)Pckts Wrote: Wild indian tigers differ from location to location, albeit small variations but still different.
Tigers in Tadoba that I saw have a darker coat and their body structure seems a little less dense compared to pench and kanha where tigers have lighter coats and seemed more muscular. The guides told me that the more hilly areas in Kahna produced larger tigers, not sure if it's true or not, it's hard to tell with the naked eye. But I definitely think the fact that Kanha and Pench or much more hilly with dense vegetation year round, especially Kanha, is a main factor as to why they seem more robust. Maybe the heat of Tadoba plays a role in the Tigers appearance as well, may be not. I would assume that the same should hold true with Amurs, the ones living in hilly terrain should could be more powerful than others. The fact that they have less prey now a days spread over vast territories and the need for fat reserves in the winter may also contribute to their "lean look" in summer months. But in regards to "athletic look" I think you can look towards females and see that there is probably not much difference. I think you'd be hard pressed to find a more athletic tigress than what you see in central india. Males are harder to determine since I only saw 2 and both were large, bulky individuals.

DIFFERENCES BETWEEN AMUR AND INDIAN TIGERS

Although the treats discussed in the previous post are arbitrary, there is reliable information pointing in the direction of distinct regional differences in India. A century ago, tigers shot in the northern part of India were longer and heavier than in southern India. Nepal tigers topped all tables. 

After World War One, the situation drastically changed in many parts of Asia. Amur tigers nearly completely disappeared in the first decades of the last century. They adapted to more pressure and smaller prey animals by droppping a few inches and pounds. I'm not sure about the conclusion in a paper published a few years ago (in which it was concluded that most historical records are unreliable), but today's Amur tigers do seem smaller than a century ago.

Apart from the reasons mentioned before (habitat destruction, prey depletion and tough conditions), I noticed a very limited amount of individual variation in wild Amur tigers. This most probably is a result of the population bottleneck in the thirties and forties of the last century: only 10-15 tigresses survived the unslaught. In Korea and Manchuria, tigers have disappeared completely. 

Tigers in India and Nepal also were severely threatened in the sixties and seventies of the last century, but there were still more than a thousand tigers left when it was decided to protect them. Those living in reserves today can hunt large animals and the result is many tigers in smallish reserves. As leaving the reserve usually is not an option, competition is intense (see Betty's last post). This might have resulted in robust survivors. 

In the end, however, conditions could be decisive regarding size. A large and robust specialist facing smallish prey animals, periodal migrations of deer and wild boars, long winters, deep snow and long distances on a regular basis will struggle with energy deficits every now and then. Loss of size is perhaps the best way to adapt. That and the ability to walk long distances (territories of Amur tigers are much larger than in India or Nepal).         


FEMALES

Sexual dimorphism is very outspoken in all members of the Panthera family. Biologists think that sexual drive is the main reason. When measuring tiger skulls, I noticed that female skulls are not as well defined as male skulls. There are distinctions between subspecies, but they are limited. 

Based on what I have, I'd say that individual variation in Indian tigresses is more outspoken than in other subspecies. Some females are nearly twice the size of others. If we add other measurements, the conclusion on size (between Indian and Amur tigers) is similar as in males in that Indian tigresses, at about similar length, usually are heavier. If you would compare dozens of photographs of wild Indian and Amur tigresses, you would most probably see a pattern. What you see isn't always clear as a result of the outspoken wintercoat and the relatively large skull of Amur tigresses, but they are not as heavy as Indian tigresses. From a distance, you'd conclude that one of the two offered speed and agility for more power. This most probably is an adaption to prey size.

When I would be able to get to a few tables, the results most probably underline the impression I have. You can also see it in captive tigresses. I've seen quite a few Amur tigresses exceeding 8.8 in total length in a straight line, but nearly all of them were very symmetrical in built. Captive Indian tigresses, like captive lionesses, often are shorter and more stocky. Same for extra-large individuals.   


ATHLETICISM

When I refer to 'athleticism', I mean symmetry. This means that not one factor really stands out. Maybe symmetrical big cats differ from robust big cats in that a robust cat is robust in all departments, whereas a symmetrical cat is reinforced in some parts of the body without sacrificing agility and speed. 

The most symmetrical cat could be the puma (a large small cat), closely followed by the leopard (a big cat of similar size). Of the other large cats, the tiger is the most symmetrical. This means that tigers often combine strength with speed and agility. Lions seem to be a bit 'top-heavy' and, whereas jaguars are robust in all departments. 

In specialised hunters, like wild cats, one often notices a balance between length, weight, strength, agility and speed. But often isn't always. In a cheetah, strength and agility were offered for speed. Jaguars offered speed for strength and lions offered symmetry for a top-heavy front. In pumas, leopards and tigers, balance is the first word that comes to mind. In general, it's easier to be well-balanced when you're not too big. A tiger is the exception to this rule. For this reason, I consider it relatively more athletical than the other big cats.

When you see a tiger, you see symmetry. A large male tiger from northeast India, however, is more robust than anything else. Some males are built like a tank. When you think of athleticism, you don't think of a tank.                    

Wild Amur tigers and wild Indian tigers are similar in length and limb length, but Indian tigers often are more robust and heavier. The emphasis is on power, whereas it is on legs in many wild Amur tigers. That and length.

  
SOME EXAMPLES

1 - Puma (Zoologischer Garten, Berlin)

Southwestern part of the USA. Spine long, legs muscular and hindlegs longer than front legs. Skull small. Most athletic of all large cats. Pumas have killed and eaten humans, but incidents of this nature are very rare: 

*This image is copyright of its original author

2 - Leopard

2a - Java (Zoologischer Garten, Berlin)

This is an adult male. Similar in length to the puma above, but hindlegs shorter and skull larger. This cat also is very athletic, but it's more robust and not as fast as a puma. Leopards are more visible than pumas and less timid: 

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2b - Northern India 

Although larger and more robust than the Javan leopard above, this male still was well-proportioned. It was shot because it was a notorious man-eater:  

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3 - Lion

3a - Zimbabwe

Adult male lion Zimbabwe. About as large as an Indian tiger, but more cursorial and, as a result of the large skull, a bit 'top-heavy'. Good for penetration, but a bit unstable in heavy seas. Not afraid of humans. Athleticism isn't the word first that comes to mind when you see a male lion:     

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3b - Okavango

Pride male in his prime. Long-skulled, robust and very present, but not athletic: 

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4 - Jaguar

Photo Sascha Siemel. Large male jaguar with a large, wide skull, a powerful neck and robust limbs. Raw power, but not a prime example of athleticism:

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5 - Tiger

5a - Central India

Although much larger than the wolf, the tiger could get to him. The wolf knows. Wild male Indian tigers often are robust animals. This male still had a bit of growing to do. Less top-heavy than an average lion, Indian tigers also are more elusive and more aggressive towards humans. They still kill dozens of humans every year. Spine long and bow-shaped, long and muscular legs and a more rounded, large skull:   

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5b - Sumatra 

This male is wel-balanced in all respects. Maybe this is 'Fearful symmetry':

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5c - South-central India

Adult male in his prime (Raja). Although very muscular and tall, this male also was fast and agile: 

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5d - Northeastern India

The male below is so robust that he almost seems a dwarf, meaning he lacks length in all respects. He didn't. I'm not saying that all wild males in Kazirangha compare to him, but the number of photographs of robust males in that region is quite extended. When trying to find words to describe him, athleticism would come last.

Those who hunted Assam tigers a century ago wrote that not a few males hunted buffalos and elephants. Today, some male tigers added rhinos to the list. The conclusion is that tigers in northeastern India adapted to large prey animals. The result is a stocky and robust animal. Not longer, but heavier than in most other regions. 

Assam females also hunt large herbivores at times, but not as often. Although relatively less robust than males for this reason, they still outaveraged tigresses in other regions a century ago. 

The male below, although exceptional, illustrates the robustness typical for quite many Assam male tigers:     

*This image is copyright of its original author

5e - Russia (Baikov, 1911)

Although I have seen captive male Amur tigers that, weightwise, compare to some of the largest wild male Kazirangha tigers, most wild Amur tigers today are about as heavy as an average wild male tiger from central India a century ago (170-210 kg.). At that weight, they could have slightly longer skulls and legs. Although the front limbs are bigger, the body usually is less robust.   

Wild Amur tigers often struggle with long winters, deep snow, few prey animals and, as a result, periodic energy-deficits. A century ago, they followed wild boars when the herds moved as a result of a crop failure. Today, they sometimes enter villages when the going gets tough. Most of them are adolescents and young adults ranging between 18-48 months. Learning how to survive takes a lot of time. Not every adolscent grows into an adult.

The tiger below, at 11.7 'over curves' in total length and 560 pounds, is the accepted record but experienced researchers think large males might reach 600-650 pounds at times:

*This image is copyright of its original author

Surviving includes learning how to deal with bears. The photograph below is a bit deceptive, as the tiger seems to be as big as the bear. This is not the case. Adult male brown bears average about 270 kg. (just under 600 pounds): 30-40% heavier than a male tiger of similar length (referring to head and body length).

Amur tigers hunt bears, but most bears killed are smaller (about 100 pounds, Bart Schleier thought). Although interactions have been witnessed, male tigers and male bears seem to avoid each other. Male tigers are seldom displaced, but females with cubs are more vulnarable:    

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