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

[peter]

Interesting. But what was written about the wild boar found close to Uporny? Was it completely eaten, or partly?

As to the size of brown bears and the interactions between tigers and brown bears. At about similar head and body length (190-200 cm. 'over curves'), male brown bears average close to 600 pounds, whereas male Amur tigers, according to Miquelle, average 430 pounds. Male brown bears, therefore, are heavier and more robust. This should result in an advantage in a fight. It should also result in displaced male Amur tigers. However:

1 - The samples on adult males (6 years and over in tigers and 9 years and over in brown bears) are too small to get to solid conclusions on size.

2 - It's unclear if the brown bear averages I saw were corrected for the effects of season and hibernation.

3 - Although Krechmar, an undisputed authority on bears and tigers in the Russian Far East, thinks a large male brown bear would go unchallenged (some individuals well exceed 1 000 pounds), he also thinks there's little to choose between most male tigers and male brown bears. Fights do not produce consistent winners, he wrote. 

4 - Reliable information about tiger kills, scavenging bears and conflicts suggests that most tigers are not displaced. Most of those that were displaced were females. This, indirectly, confirms the opinion of Krechmar (see -3-). 

5 - A recent article about food habits of Amur tigers posted a week ago (this thread) strongly suggests that bears (black and brown) are more often hunted than was assumed. Based on the tables in the article, the bears hunted are far from small. The outcome of the study, as Kerley and the others concluded, runs counter to the widely held assumption that bears are too dangerous to hunt for tigers.

6 - Although many think that adult males of both species avoid each other, it could be quite different. There are 13 brown bears to every tiger, meaning they are bound to meet each other. For a tiger, it most probably starts at a young age. Young tigers just can't avoid bears, especially at kill sites. For a tiger, a confrontation with a bear either means hunting again or defending a kill. Some will avoid a fight, but others will not. Tiger Boris, not even a young adult male when he was released into the wild, could have been forced into fights with bears interested in his wild boar kills. It resulted in 2 dead bears. Although they were young, a 3-year old brown bear is not a joke. If Boris grows into an adult, chances are he will use his experience to hunt bears. If he tries his luck with an adult bear and the fight is not going his way, he can get out. For a bear, this is more difficult. 

Maybe experienced tigers avoid large bears, but there's no question that some tigers attack larger (heavier) bears at times. If a tigress is able to kill a heavier bear (referring to the 1951-incident near the Tatibe River), so is a male tiger. Although the outcome of a fight between adults could be unclear (no consistent winners, Krechmar wrote), there's no doubt that adults meet and engage at times. Statistics published by Russian researchers show that male tigers have been wounded and killed by male bears and the other way round. 

Psychology could be a factor. Adult male Amur tigers are survivors that don't take an offence lightly. If they are displaced by a larger male brown bear, they might develop a grudge that could result in an all-out fight one day.

The outcome of fights depends on many factors. Two factors that need to be considered are the effects of crop failure and the effect of hibernation. If bears can't fatten up in autumn, they can't hibernate. Most non-hibernating bears don't survive the long winter in the RFE. Those able to hibernate lose 25-35% of their autumn weight. The bear killed by a tigress near the Tatibe River was estimated at about 170 kg. in early May meaning he could have been well over 200 kg. in late autumn. A few years ago, an article was published about Amur brown bears. Two adult males of 8-10 years of age were 180 and 235 kg. in autumn. Weightwise, they could be vulnarable in early spring. 

Something else to consider is inborn dislike and instinct. Captive tigers don't fight other animals for food or domination. They fight animals they dislike. Time and again I noticed that captive Amur tigers dislike bears. They will never really let go of it, until a decision has been reached. Some trainers say that tigers often get involved in fueds, but it could be more primitive than that. If we add planning, which seems to be typical for tigers in particular, the most usual result is an all-out at some stage. The animosity between Amur tigers and brown bears, if it can be described in this way, is way more intense than the animosity between lions and tigers.     

Apart from large male bears, I'd say that things are unclear between adult male Amur tigers and adult male brown bears. I'm sure they meet and I'm also sure they engage at times. The outcome of these bouts is anybody's guess. As Kerley wrote in her mail to 'Jungle Sprout' recently posted in this thread, anything is possible between tigers and bears. Maybe a researcher could get lucky on day, but most clashes will go unnoticed. The Russian Far East, although no longer a 'sea of forest', still is a very large region with few people. Reply