Here are some real fighting records of Asian Siberian brown bear and Siberian tiger. Please have a look (Alaska brown bear in the United States is bigger than Asian brown bear, and it is the largest brown bear).
First of all, the predatory relationship between tigers and bears
(A) the tiger's predatory behavior on bears
According to the official document of the Northeast Tiger Project, "the prey of tigers includes black bears, underage brown bears and female brown bears, and adult male brown bears are not in the tiger's diet". "Only adult male tigers have the ability to include bears in their daily diet." Therefore, the predation of bears by tigers is actually mainly the killing of black bears, underage brown bears and female brown bears by adult males.
1, the position of bears in tiger diet
(1) Tigers (mainly adult males) frequently attack bears. According to the statistics of tiger hunting times, the frequency of bears is 7. 1% (including 5.2% for black bears and 1% for brown bears). Excluding the dormant period of bears (late autumn, winter and early spring), it reached 1 1.4% (including 8.3% for black bears and 0/.3% for brown bears). The proportion in autumn is as high as 20.4%, indicating that tigers attack bears mainly in autumn.
Although the frequency of tigers attacking bears is very high, in fact, bears account for a small proportion in the tiger's food composition, accounting for only 2. 1% in terms of dry weight of feces and stomach contents (including black bears accounting for 0.7% and brown bears accounting for 1.4%). The main reason here is that tigers usually attack cubs or very young bears, and their weight is very small, resulting in a small proportion of bears in tiger food (Khramov, 1993). Among them, the difference between the two proportions of black bears is particularly great, because black bears are smaller than brown bears.
(2) We can make a simple calculation and estimate the average weight of bears killed by tigers. As mentioned above, according to the statistics of tiger hunting times, the proportion of bears is 7. 1% (including 5.2% black bears and 0/%brown bears); However, the dry weight of feces and stomach contents is only 2. 1% (including 0.7% for black bear and 1.4% for brown bear). Roughly speaking, the average weight of bears killed by tigers accounts for only 29.6% of the average weight of all tiger prey (2.1%/7.1%). The average prey weight of Bengal tiger is about 65kg, but compared with Northeast tiger, there are few similar studies. Limited samples show that the average prey weight of Amur tiger is 93.6kg(n=63). This simple calculation shows that the average weight of bears killed by tigers is only about 28 kilograms.
(3) In addition, it is found that bears are not the first choice prey for tigers. Only when ungulates become scarce, the proportion of bears in the tiger's diet will increase, especially in the 1940s and 1950s (1944 to 1950, 17 cases of tigers attacking bears were observed, and most details were not recorded).
(4) The researchers said that tigers kill bears mainly to kill sick individuals, which is beneficial to the bear population.
2. Several examples of tigers killing bears observed in the Northeast Tiger Project.
Nine tiger bear killings were recorded here, including 6 brown bears (5 females, 1 cub) and 3 black bears (2 males, 1 unknown). No adult male brown bear was killed; Except for a few unidentified males, all bears were killed by adult male tigers.
A very powerful tiger named Dell was observed in this project, weighing 202kg, which is almost the largest tiger found in this project, numbered M20. He killed four female brown bears and 1 male black bear. Of the four female brown bears killed, two were killed in a simple process. When the other two were killed, they resisted stubbornly, and Dale bled to death in the battle. It is known that the weight of one female brown bear is 150-200kg. It can be seen that it is very dangerous to kill the female brown bear.
3. Other examples of tigers killing bears, in which tigers are all adult male tigers except a few with unknown sex. Russian place names are too difficult to translate, so they are all omitted. In a word, they are in Primorsky Krai. As for the size and sex of bears, it is quoted that "the sex of bears is not always given, but judging from their size, there are obviously no adult male brown bears".
① Grokhoff (1973): A male tiger killed a female brown bear after fighting for 20 minutes.
②Kondakov( 196 1): A male tiger killed and ate a brown bear.
Up to now, the only case in which a tigress successfully killed a brown bear. 195 1 year, a tigress killed a sub-adult brown bear by the river, with a body length of only 158cm and an estimated weight of 170kg. Note that this bear is very short, not as long as the tigress, but it is estimated that it weighs a lot, probably because it has more fat.
(4)/kloc-in the winter of 0/949, a hunter found a dead black bear with severely torn skin, apparently killed by a tiger.
4. Some cases where tigers failed to kill bears.
Kostoglot (1981): A tigress with a cub tried to kill a brown bear. The brown bear began to try to escape, then turned to resist, and the mother tiger was finally forced to give up and leave with her cubs.
② Gorokhov (1973): A tigress tried to kill a brown bear. After a simple struggle, the tigress escaped.
③ Gorokhov (1973): After a long struggle, a tiger and a brown bear left in the opposite direction. The tiger was seriously injured and his mouth was bleeding.
5. The problem of tigers killing hibernating bears.
(1) There are several examples in history in which tigers killed hibernating bears. Bromely (1965) was the first to discover that tigers can kill hibernating bears. He studied in the middle of the West Hote Mountains for seven years and observed that 15 tigers attacked hibernating bears, mainly in late autumn and early spring. He claimed that only the biggest brown bear could escape being killed by a tiger during hibernation.
① bromley (1965): A tigress with a young female black bear dug a cave, dragged the female black bear out of the cave and killed it. The female black bear weighs about 80-100 kg; The tigress killed another bear weighing 30 kilograms.
(According to the paper, there are only two confirmed cases of female tiger killing bears so far, and the other case is killing a sub-adult brown bear, as mentioned earlier. )
② Yudakov (1987): A female tiger dug a hibernating cave of a male black bear and tried to kill it, but finally the female tiger escaped.
(3)1949 In the spring, a little black bear climbed the tree several times to avoid being chased by tigers. Judging from the fallen bark, the tiger spent quite a long time attacking the bear.
(2) With regard to the research on the killing of hibernating bears by tigers in Northeast Tiger Project, during the period of 13 years (1992-2005) since the beginning of Northeast Tiger Project, no incidents of killing hibernating bears by tigers were observed. But the existence of this phenomenon can be confirmed.
Male tiger M4: It contains bear's hair and claws in its feces in summer and winter. The researchers also found him searching the bear's cave and trying to kill the hibernating bear.
② Female tiger with cub f 2: In the spring of 2004, F2 tried to kill a hibernating female black bear. The researchers found that she climbed a very tall tree, but still could not reach the hibernating cave of the female black bear.
(3) Some new conclusions of Northeast Tiger Plan.
A recent study by WCS found that the relationship between bears and tigers tends to ease after hibernation. Although it has been proved that tigers do kill hibernating bears, it is far less frequent than previous researchers thought. The frequency of bears being attacked by tigers in hibernation is obviously less than that in activity.
On the other hand, after most bears go into hibernation, the situation of the female tiger will be much better, because bears often snatch the prey of the female tiger, while the male tiger is generally unaffected.
At the same time, the researchers also found that adult male brown bears generally do not hibernate, and spend the winter by grabbing the prey of tigers.
(2) The predatory behavior of bears on tigers
1, the position of tigers in the diet of brown bears
Many incidents in which brown bears killed tigers were caused by fighting for food, but sometimes brown bears also took the initiative to kill tigers.
(1) The brown bear's diet is 90% vegetarian. Except in spring, the brown bear who just came out of the hole urgently needs a lot of high-protein food to supplement the energy consumed during hibernation. WCS research found that tigers accounted for 0.5% of brown bears' spring diet. This value is lower than the proportion of bears in the tiger's diet (2. 1%).
(2) Brown bears are a great threat to tiger cubs. Gorokhov (1972) counted the deaths of 14 tiger cubs, three of which were killed by brown bears.
(3) According to the research of 3)WCS, it is very dangerous for female tigers with cubs to face brown bears, while adult male tigers are enough to repel other bears except oversized brown bears. After the bear hibernates, it will be much better for the mother tiger with her cubs.
(4) Kostoglot (198 1): Most tigers killed by brown bears are sick tigers, so the activities of brown bears help humans to control man-eating tigers.
(5) Some cases of brown bears preying on tigers.
(1) Lakoff (1959): A brown bear killed a tigress who came to eat beside the dead boar he killed.
② Sysoev (1960):1In the winter of 959, a big brown bear killed a young tigress on the way back from hunting wild boar, and was seriously injured at the same time. Later, he ate wild boar and tigress.
(3) Krivopsk (1957): 1956 In the winter of 1956, a female tiger with a 3-year-old male tiger (older than the female tiger) killed a wild boar, and a brown bear who didn't hibernate because of lack of food killed the male tiger while the female tiger left, and then ate the wild boar.
④ abramov (1962):1913, a big brown bear killed an adult male tiger, and the male tiger was "shredded".
⑤ abramov (1962):/kloc-0 In the winter of 960, a brown bear killed a young male tiger.
⑥ Kostoglot (198 1): A brown bear caught, killed and ate an adult male tiger.
The sex of the brown bear is not given in the above example, but the "big brown bear" and "non-hibernating brown bear" can only be adult male brown bears (adult male brown bears have the habit of non-hibernating), so although there is no explanation, in fact, the above tigers are basically adult male brown bears.
(6) Some cases in which brown bears hunted but failed to catch tigers.
① In the Northeast Tiger Project, a tigress was found to be followed by at least two brown bears, and one of them later ran after the tigress.
② In the Northeast Tiger Project, a brown bear was found to be very close to a female tiger with cubs twice.
(3) Kostogold (1981): A brown bear followed a 22km male tiger and tried to kill it; Later, the lucky tiger escaped bad luck by getting close to the residential area.
Unlike brown bears, black bears seldom fight back against tigers. Sisojev (1960) recorded the only fight between a black bear and a tiger. Generally, black bears take the initiative to avoid tigers. When you meet a tiger, you usually climb a tree and run away. There has never been a record of a black bear killing a tiger.
Second, the competitive relationship between tigers and bears.
This mainly refers to the relationship between the two in grabbing food.
1 and 1992-2002 found that 16.7% of the prey caught by tigers will be visited by brown bears, and 20% of the carrion of brown bears comes from tigers. Adult male tigers can basically keep their own food (a small number of adult male tigers will be robbed of their prey), but this is very unfavorable to female tigers; Brown bears are the main prey of female tigers, and occasionally there are adult male black bears.
The 36 cases observed can be divided into the following four situations:
16 cases (44.4%), bears washed tigers and ate leftovers (1 1 cases were brown bears, 2 black bears and 3 unknown bears);
4 cases (1 1. 1%) of bears drove tigers away to grab prey (2 cases were brown bears, 1 cases were adult male black bears, and the rest 1 cases were unknown; Tigers are all females);
In 4 cases (1 1. 1%), tigers and bears shared their prey (both bears were brown bears; Tigers are all females except a few unknown sexes);
12 cases (33.3%) have unknown details. ?
2. Other materials to supplement the above materials.
① Kostoglot (1976): An adult male tiger returned to his prey only to find a male brown bear eating. After a brief confrontation, the tiger was forced to retreat and the brown bear enjoyed it alone.
② Grokhoff (1973): A bear attacked a tiger and took its prey.
Researchers of Northeast Tiger Project once found a male tiger and a brown bear face to face next to a dead red deer, and finally the male tiger retreated first. There are two situations in which bears kill tigers for food (Sysoev,1960; Krivopusk, 1957), the female tiger and the sub-adult male tiger were killed respectively. I have explained it in the last section, so I won't repeat it.
Tigers occasionally eat carrion. In this project, a tigress was found following three brown bears and eating the rest of the wild boar. It was also found that a male tiger ate a dead brown bear, which was killed by a bigger brown bear. Lakoff (1959) also recorded an incident in which a tigress was killed while stealing the prey of a brown bear, as mentioned earlier.
Black bears usually avoid tigers very carefully and seldom patronize tiger prey. In addition to the case found in the project in which a male black bear drove a female tiger away to snatch prey, Yudakov(2000) also reported an example in which a black bear followed the tiger's footsteps and cleaned up the tiger's leftovers.
5. abramov (1972): During the famine years, bears became fierce and aggressive, and more actively grabbed the prey of tigers.
As mentioned earlier, tiger attacks on brown bears will increase in famine years. It can be seen that the decrease of ungulate density will lead to the intensification of competition between bears and tigers.
As mentioned above, recent research shows that adult male brown bears don't hibernate, but spend the winter by grabbing the prey of tigers.
The above is the relationship between the Northeast Tiger and the Big Brown Bear, as well as the record of fighting and competition.
We can conclude that
Male brown bear >: male Siberian tiger >: female brown bear/female Siberian tiger/male black bear >: female black bear