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

[peter]

POSTS 1102-1106 - Bears and tigers in the Russian Far East 

a - The relation between age and size

There's no doubt whatsoever that there is a clear difference between between young adult tigers (3-5 years of age) and mature animals (6 years and older). Same for young adult male brown bears (4-9 years of age) and mature animals (9 years and older). The difference between young adults and mature animals in both species (about 1-4 years) is a result of genes: brown bears live longer than tigers and need more time to mature. 

The differences between both age groups are expressed at the level of averages. Let's take the table posted as an example. Young adult male grizzly bears in the USA averaged well below 400 pounds, whereas those of 6 years and over, apart from a few exceptions, averaged well over that mark. 

Bear biologists consider animals of 9 years and older as mature. Mature male brown bears, as Brotherbear wrote, are quite close to 500 pounds. At the level of individuals, however, things are more complicated. A 4-year old male brown bear can be larger and heavier than a 14-year old.

b - Disputes at kill-sites

In the Russian far East, bears (Himalayan bears and brown bears of all ages, so it seems) often visit tiger kills. Not seldom, tiger and bear meet near these kill sites. At times, conflicts erupt. Some of these end in a tragic way. Bears can displace tigers (and tigresses in particular, according to Seryodkin), but the opposite also is true. Russian biologists concluded bears initiated more fights, whereas tigers won most. As details about these interactions often are lacking, it's difficult to get to conclusions. However.

c - Tigers hunting bears 

Biologists know a bit more about tigers hunting bears. Most of these specialists were older males. Schleyer, who followed the tracks in the snow, concluded the tigers had a clear advantage in that they had about a hundred pounds on the bears they hunted. This, however, wasn't always the case. The largest bears hunted were adult females ranging between 150-200 kg. (visual estimation). Although all bears hunted were killed, it wasn't always easy. Two large females were killed after a 20-minute fight and in both cases the attacker was injured. All bears were killed with a bite to the base of the neck.  

Biologists long assumed that bears are too dangerous to attack, but in a recent paper they admitted they could have been wrong. Bears apparently are more often hunted than they thought and not all bears were as small as they assumed.       

d - The difference between a young male brown bear and a mature male of similar weight

Tiger 'Boris', although not yet mature, twice killed a bear. In both cases, the bear, if understood correctly, was killed near the kill site. Although details were lacking, biologists concluded the bears could have ranged between 2-4 years of age. Some bears of that age can be as heavy as an adult male tiger (350-450 pounds), but they lack the experience of the tiger and it would be premature to get to conclusions: a 4-year old male brown bear of, say, 380 pounds is a very different animals than a 10-year old brown bear of that weight. If a 4-year old decent-sized male brown bear would be killed in a fight, it doesn't mean a 10-year old of that size would be killed as well.  

e - Brawls - classified results and authorities

According to some AVA-posters, Russian biologists had a sit-down on bears and tigers somewhere in the sixties or seventies of the last century (before the Americans arrived in 1992, that is). They concluded brown bears would win on points. The reason is size. After they exceed, say, 400-450 pounds, males develop extra layers of muscles in the area targeted by tigers in a fight (shoulders and neck). As a result, tigers would need too much time to score a point. Furthermore, while trying to force a decision, they would become vulnarable themselves. One could say, as Pikunov did, that tigers wear themselves out, but one could also say that mature male brown are too large, too robust and too agile to be killed quickly. 

Furthermore, Russian 'black grizzly's' are known for their disposition (they have killed much more humans than Amur tigers). They also have much larger teeth than their, larger, Kamsjatka relative. Lastly, one has to consider the occupation of both. A tiger, as a professional hunter, would try to avoid injuries: he can hunt again. Russian brown bears can not. At least, not as good as tigers. This is the reason they are willing to take a risk, one would think.

But winning on points is different from killing your opponent. In an all-out anything is possible if both are about similar in weight and age. Furthermore, bears of some size have been killed by tigers. Although all of them were non-hibernating males (Shatuns) or bears just out of hibernation who most probably had lost a lot of weight (brown bears can lose 25-30% of their weight during hibernation), the outcome of a fight to the end is anything but clear.

Krechmar, a hunter, biologist and undisputed authority on bears and tigers, said big bears would get it their way. But large animals are few and far between and the differences between most male tigers and bears in the Russian far East are limited. There are no consistent winners, he concluded. Vaillant, who talked to many in the know, also wrote tigers avoid big bears. But they are prepared to confront a bear of similar size and, more often than not, are able to get it their way.  

f - The difference between brawls and a lifestyle  

Fights at kill-sites, although not very rare, are different from a lifestyle. It is a fact that Amur tigers hunt bears. Black and brown bears. In some regions and some seasons, bears are as important as wild boars and deer, if not more so. Not all bears hunted, as many seem to think, are immatures. Those who got to that conclusion are not operating in the amateur division, but in the Premier League. They published papers and articles and all of them are based on solid research. That should tell you something. I am definitely interested in sit-downs of specialists who knew more than all of us combined and I also agree with their conclusions, but it is a fact that bears are important to Amur tigers.

g - My opinion on bears and tigers in the Russian Far East

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*This image is copyright of its original author

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In short:

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