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

[peter]

(09-15-2014, 10:55 PM)'Pckts' Wrote: Very impressive to see that Bears made up 31% of a tigers diet. But I notice that tigers may be forced to hunt them more due to the lack of wild boars and once wild boars were abdundent, bears where not targeted as much. I wonder if over hunting of hooved animals will/has caused tigers to hunt bears more and more.
Very interesting read, tfs.

 

Not quite. Availability, of course, has something to do with it, but the real reason could be natural balance. If a predator selects different animals in different seasons, prey animals have a chance to recover. This will result in more balance and more balance is a better future.

In the region studied, tigers hunt bears in every season. When wild boars and red deer are available, tigers hunt them more often than bears, but that doesn't mean black bears are not hunted at all.

We have to remember Tkachenko's results relate to 3 adult tigers (two males and one female) in one region only. In other regions, bears are not hunted at all. Another conclusion is bears are not only hunted by male tigers.

It is not known why some tigers hunt bears and others do not. Russia has a limited number of herbivores and quite many bears. Tkachenko concluded black bears do not fear tigers. Many visit tiger kills when possible. Any tiger even remotely interested in bears would get a chance to test bears at some time. Maybe those not hunting bears had a bad experience and maybe those interested had a different experience.

Some years ago, I read everything available on bears and tigers. I concluded bears and tigers most often meet near kill-sites. At times, there are encounters, but in most cases the animals radiated. When fights erupted, most had a tragic outcome. Tigers won most fights, but bears didn't do that bad.

Anything known on these fights? Not much. The researchers often were unable to conclude anything on sex, age and subspecies. What is known, however, suggests adult animals perished in fights as well.

Anything known on adult males? A bit. There was a long and interesting debate in a thread on bears and tigers in AVA some years ago. Krechmar, a renowned Russian biologist and hunter, featured in quite many posts. When asked about fights between males, he said not one dominated the other in a fysical fight. When average weights for both are included (male brown bears average 250-270 kg. and male tigers between 170-212 kg.), one could say male tigers do quite nice. Winner on points, perhaps? 

Not quite. Some male brown bears easily exceed 300 kg. and one would think they would be able to take any tiger kill. Krechmar confirmed and so did Sludskij and Sysoev. As they don't come more experienced, the conclusion has to be big male brown bears get it their way. The Russian biologists, therefore, concluded there is a winner on points. And he has no stripes.

Could have been different in the recent past, tiger posters think. A century ago, some tigers also reached 250-275 kg. or even more. They have a point, although exceptions are different from general rules. In 1943, an exception was photographed near the remains of a big male brown bear he had killed and eaten. This incident, however, wasn't accepted by researchers. No passport, no case and case closed, they concluded.

Today's tigers seem a bit smaller, but Krechmar thinks Russia still has wild large Amur tigers. He saw prints of extra-large tigers and as he has personal experience we have to assume he is right. In an indirect way, he was supported by the two male tigers who destroyed the much critisized Aldrich-snare. Both were large. Maybe larger than 'Luke', who leads the table for now. Luke, although heavy at 212 kg., wasn't impressive in lineair measurements (183 cm. in head and body straight).

And my stand?

The more I read, the more I'm convinced things are not that different from a century ago. It depends on the circumstances and these seem to improve in both Russia and China. Modern wild males range between 360-470 pounds, but maybe large males are able to destroy the Aldrich-snare.

If Amur tigers would compare to Indian tigers, the heaviest wild Amur tiger could exceed an average male by 35-50%. This would result in 480-700 pounds. In theory, of course.

The heaviest males actually weighed (and accepted) ranged between 550-560 pounds. The giant shot in 1943, at about 650 pounds, was heavier and (at 11.6 feet 'over curves') longer, but he had just finished a large bear when he was shot. If we include captive Amur tigers (those in the overweight department excluded), one would expect to find a freak of 650 pounds or even a bit more once in a generation. But 430 pounds apparently is just about enough to prevent getting robbed by an average male Amur bear.

We could conclude any statement on tigers and bears depends on the angle and be right. We could also say not enough is known. There are not enough data. Unclear, I concluded. Reply