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

[Apex Titan]

The size of bears hunted by Amur tigers

In the Russian Far East, its well known that tigers habitually hunt and kill both brown bears and Himalayan black bears. So much so, that some tigers become bear specialists and prefer eating bears to ungulate prey animals. In this region, tigers are the main natural enemy and predator of bears. So do Amur tigers target large bears as well? Or do they mainly hunt small bears like some people assume?

Based on scientific research and observations from various leading experts, biologists and researchers, its an established fact, that tigers definitely hunt and kill both large brown bears and black bears, more often than previously assumed by some biologists. Studies show that tigers mostly kill and eat adult bears and hunt these bears especially in summer and autumn, the seasons when bears are at their peak weights and condition.

Since numerous studies consistently show that tigers primarily hunt bears in summer and fall, and since studies show that biologists and researchers found mostly adult bears hunted and killed by tigers, its safe to assume that large bears must be killed too. This is confirmed by several other accounts of tigers hunting and killing large brown bears, as well as recent sources.

*This image is copyright of its original author

Research and evidence from Russian experts confirms that tigers prey on big bears as large and larger than themselves. Baikov stated (based on his observations) that large tigers kill bears of the same weight, which proves that large tigers successfully hunt large bears of similar size. i.e. Bears weighing well over 200 kg hunted and killed by tigers. There's no doubt that tigers predate on large bears.

Some people speculate that tigers would prefer to hunt small bears, but Tkachenko, Dunishenko, Matyushkin, Batalov, as well as WCS RUSSIA biologists and field researchers observations/reports, proves that male tigers hunt and kill large adult bears. Tigresses are the one's who usually hunt small to medium sized bears, but male tigers (as mentioned in my previous post) have the size, power and strength to regularly hunt and kill large adult bears. A tiger needs large prey animals to kill, scientific studies from the Russian Far East, India and other countries and regions of Asia, consistently show that tigers (male & female) always go after the largest prey animals available. Tigers are specifically built to be big game hunters, this is why even female tigers are well known to single-handedly hunt and kill large bull gaurs 7 times their own weight and huge bantang bulls weighing 800+ kg.

A small bear, in general, is not gonna satisfy such a large apex predator like a tiger, as 'energy maximizers', tigers prefer to kill large/very large animals to maximize their energetic return. Thats why tigers usually hunt adult bears, wild boar, elk and red deer. Tigresses have also been confirmed hunting and killing larger bears (Bromley). When it comes to Himalayan black bears, scientific research confirms that tigresses also successfully hunt both adult male bears and females, and have also been recorded killing adult brown bears (Kaplanov 1948; Bromley 1965).


Tigers hunting bears - Observations from Tkachenko

Konstantin Tkachenko, a zoologist, biologist and researcher, who studied the feeding habits of bear-hunting tigers in the Khekhtsir reserve, observed and reported that when tigers hunt brown bears and black bears, male tigers more often hunted adults, larger bears, whereas the tigress nicknamed "Three-toed" mostly hunted young bears:

*This image is copyright of its original author

https://elementy.ru/nauchno-populyarnaya...stvovaniya


Brown bear made up 18.5% of the tigers diet

"According to K.N. Tkachenko, in the tiger feces he studied, the share of the brown bear was 18.5%, while the share of the white-breasted bear was only 14.8%. In general, in the diet of a tiger, the brown bear firmly held the honourable third place, leaving only wild boar (37%) and red deer (29.6%)."

https://shish02.livejournal.com/7269.html?thread=55909

Brown bear made up 18.5% in the tigers diet and Himalayan black bear made up 14.8% in the tigers diet:

*This image is copyright of its original author

Russian biologist, tiger ecologist & senior researcher - Yuri Dunishenko (2021) stated that tigers kill large bears with a bite to the base of the skull, which again, confirms that tigers hunt and kill large bears and are able to dispatch big bears with a bite to the base of the skull, which indicates to the immense jaw power of the tiger.

"All experts indicate one reason for the death of the victims - the destruction of the cervical vertebrae at the base of the skull. In this manner, the predator kills even a large bear."

*This image is copyright of its original author

http://amur-tiger.ru/data/files/files/ti...ressed.pdf


Large tigers successfully hunt bears of the same weight:

*This image is copyright of its original author

http://www.ssj.sk/sk/user_files/ACS_47_S106.pdf


Russian biologist, zoologist & researcher, Matyushkin reported that large bears are prey for male tigers:

DIET OF LARGE PREDATORS ( ON THE EXAMPLE OF THE TIGER ): METHODOLOGICAL ANALYSIS - 2008 V.G. Yudin

"As Matyushkin (1992) found out, the tiger usually hunts those ungulates that are more numerous on his site. Not only bull red deer, but even large bears and bill-hooks (large mature male wild boars) are physically accessible to an adult male."

*This image is copyright of its original author

There are also additional accounts of tigers hunting (and killing) large brown bears (Rakov 1965, E.N. Smirnov, Soviet literature 1956, Jankowski, Abramov). I also posted a reliable account of a tiger that hunted down, attacked and badly mauled a huge male brown bear. (See post #2,532)


"In December 1959 on the river, light tiger killed a large brown bear and lived around it for about 10 days until it ate."

*This image is copyright of its original author

170 kg adult brown bear killed by a tigress

In the spring of May, 1951 near the Tatibe river, Russian biologist Bromley found the carcass of a 170 kg brown bear that was killed and eaten by a tigress. Some Bear posters claim that the bear was either a subadult or fat juvenile brown bear, but there's no evidence to support such claims. According to actual evidence and reliable sources, the 170 kg brown bear killed by the tigress was an adult brown bear, not a subadult or juvenile. In fact, zoologist Mazak, in his book, stated (according to his sources) that the bear was a full-grown adult brown bear killed. 

Although Mazak wasn't an authority on tigers and bears in the Russian far east, he did have contact with various Russian researchers and zoologists.

According to this scientific peer-reviewed source, the 170 kg brown bear killed by the tigress was an adult brown bear:

"A adult brown bear killed by a Amur tigress." (Brown bear was killed in May, not April)

*This image is copyright of its original author

https://books.google.co.uk/books?id=Q9wH...wQ6AEIODAC

https://web.natur.cuni.cz/zoospol/actaangl.htm

Another thing that strongly indicates that the 170 kg brown bear was an adult bear killed, is the fact that Bromley, the biologist who found the bear, reported this specific case in the same context of tigers being enemies and predators of adult bears in the Russian Far East.

A chapter excerpt from Bromley's 1965 publication:  (Originally posted by Bear poster 'Grahhh')

BROMLEI CHAPTER ON BEARS: PARASITES, ENEMIES AND THE COMPETITORS: ( Primary source )

To the enemies of adult bears before the south of the Far East of the USSR one should add in essence of tiger. In 1940, L.G. Kaplanov (1948) for the first time saw before the sources the brown bear, torn to pieces by a tiger near the den. Based on this year similar cases before the Amur Region and the littoral were registered. It turned out that tigers press bears not only by those sleeping before the dens, but also in the period of their wakefulness. The fur of bears was repeatedly discovered in the spring and autumn excrements of tigers (on April 24, May 1, 10 November 15, November 27, November). In the beginning of May 1951 on the shore Tatibe (inflow river of Iman) based on the cry of crows was possible to find the brown bear (length of 158 cm, the weight of approximately 170 kg), slaughtered by a tigress.  In it all most fatty body parts proved to be eaten: back, ham and the accumulation of fat in the inguinal region. 10 m besides the eaten corpse were arranged the excrements, urinary points even three maturation of the tigress, that was being held here approximately of 3-4 days."

Now, if this bear was really a "juvenile" or "subadult" bear, as some Bear posters speculate or assume, then why did Bromley (the biologist who found the bear) specifically report this case in the context of tigers being enemies of adult bears? Why did a highly respected zoologist like Mazak (who had contact with several Russian researchers/biologists) also state in his book that the 170 kg brown bear was an adult brown bear killed? And why does a scientific peer-reviewed source also report that this bear was an "adult brown bear killed by a tigress" ?? ....

The true length of the bear remains ambiguous because the tigress had already devoured the bears entire (large portion) back side, and we also don't know how (which method) the bear was measured. All in all, considering all the sources reporting this case and the spring weight of the bear, the 170 kg brown bear killed by the tigress, was most likely either a large adult female brown bear or large young adult male bear.

This case also confirms that even tigresses (120-140 kg) prey on large bears, and are well capable of killing significantly heavier adult bears with no problems. Which also strongly suggests that a male tiger is also capable of killing brown bears significantly heavier than themselves.

Does tiger predation on large bears often lead to head-on confrontations?

Yes, and this is a fact backed up by numerous reliable evidence and reports from biologists, naturalists, zoologists and even hunters. Although tigers can and do kill large bears with a bite to the base of the skull, due to the thick fat layer at the nape of the bears neck, large bears cannot be killed immediately in this fashion. Tigers often end up in a fierce struggle with the bear, in which the tiger, almost always, kills the large bear in a face-to-face fight. 

This is also confirmed by accounts reported by the Siberian Tiger Project biologists, where two different male tigers attacked and killed large adult female brown bears of similar-size, after fierce, prolonged battles.

Kaplanov stated:

"The tiger kills all types of prey almost instantaneously, biting through the neck vertebrae at the back of the head with canine teeth that reach 6 cm in length. Only large bears, due to the fat layer at the nape of their neck, cannot be immediately killed." 

https://aboutzoos.info/images/stories/fi...e_Alin.pdf

Russian zoologists, Heptner and Sludskii state:

*This image is copyright of its original author

https://archive.org/details/mammalsofsov...ew=theater


Here's a depiction of a tiger killing a large brown bear by biting the base of the bears skull: 

*This image is copyright of its original author

Some people assume that only small or medium-sized bears are killed with a bite to the base of the skull, but both Baikov and Dunishenko (based on over 40 years of field experience) stated that tigers also kill large bears this way too. 

The above statements from Kaplanov, Heptner and Sludskii, refute the assumption made by some bear posters, in that, tigers swiftly kill large bears by ambush, which is not the case at all. When tigers hunt and attack large, powerful and robust animals like large bears and wild boars, the tiger in most cases, kills the large bear or boar after an intense struggle. This explains why there are numerous accounts of tigers killing large similar-sized bears and large male boars after prolonged fights.

Vaillant (who talked to various biologists, researchers, rangers & locals), in his book, also reported that tigers attack brown bears, and sometimes prosecute the battles (referring to head-on fights) and brutally dismember the bears to the point where the bears appendages are strewn across the battleground:

*This image is copyright of its original author

John Goodrich (Chief Scientist & expert on Amur tigers) dreams of watching an Amur tiger attack a brown bear. When interviewed by the BBC Wildlife on the subject, he stated that in his work, he's found many (brown) bears that were killed by tigers, and from the tracks, he could tell that the battle was impressive:

*This image is copyright of its original author

https://books.google.co.uk/books?id=GJhF...=en&gbpv=0


Note; Goodrich reported that he's found many brown bears killed and eaten by tigers, after (as stated) impressive battles. Which strongly indicates that the brown bears attacked and killed by tigers, found by John Goodrich in his field work, were quite large bears killed. A small bear, or juvenile brown bear is not gonna give a tiger an impressive battle.

The Amur tigers physical anatomy and weaponry (wide & massive skull, huge canines, razor-sharp dexterous claws, immense biteforce & massive paws and thick, muscular forelimbs) is specifically designed to attack, grapple, subdue and kill large, dangerous and robust animals like large bears and wild boars. Tigers are the perfect combination of size, strength, speed, power and agility, which makes it the extremely lethal killing machine at the pinnacle of the food-chain and ruling apex predator of its ecosystem and domain.

Huge, robust and muscular forelimbs of the tiger, allows it to grapple and overpower big, strong and aggressive animals like bears, wild boars, gaurs, wild buffaloes etc. The superior speed and agility of the tiger also allows it to out-maneuver these animals in a fight. Tigers, of all the worlds terrestrial predators, hunt and kill the most dangerous prey.

The tiger eats only large prey. The basis of its diet in nature is wapiti (elk) and wild boars, sika deer, but sometimes the tiger attacks a badger, bear, wolf and lynx. To overwhelm a wolf or grapple with such a dangerous opponent as a bear, it really takes a lot of strength. There are cases when Bengal tigers attacked crocodiles in India, because, as the eastern wisdom says, when a tiger is hungry, it eats everything."

*This image is copyright of its original author

https://www.mk.ru/social/article/2009/11...tigra.html


What is a 'large bear' killed by a tiger?

'Large bears' hunted and killed by tigers is referring to the biggest male (160-250 kg) Himalayan black bears and adult brown bears of at least similar-size and heavier. Research and observations from various experts confirms that tigers prey on large bears in these size ranges.

Himalayan black bears of the Russian Far East (Amur-Ussuri region) are the largest subspecies of Asiatic black bears in the world. Large male bears in this region can weigh up to 200 kg in the fall, with some very large individuals reaching up to 250 kg in weight. 

Aramilev in a very recent video, stated that tigers especially like to hunt Himalayan black bears in autumn when the bears have fattened up. These large bulked up bears are delicious food for tigers and tigers specifically target these type of bears.

Although most bears are killed by tigers during summer and autumn, throughout the winter, tigers will also actively search for hibernating bears in their dens. Finding a sleeping bear, the tiger will pull it out of the den and kill it. Here's an example from leading zoologist and researcher, Sergey Kolchin who found the remains of a fully-grown adult male black bear that was pulled out of his den, killed and eaten by a tiger. Kolchin regularly finds remains of bears killed and eaten by tigers all year round.

Sergey Kolchin states:

"The main natural enemy of the Himalayan bear in the Ussuri forests is the tiger. The habitats of these species in the south of the Far East coincide, forcing the bear to adapt to the dangerous neighborhood."

"An important adaptation that increases its viability in such conditions is wintering in tree hollows. However, if the entrance to the hollow is too low, near the roots of the tree, the tiger can kill the careless owner of the den."

"Once positively experienced, tigers begin to systematically check low-entry tree dens in search of prey."

Remains of an adult (mature male) Himalayan black bear killed and eaten by a tiger:

*This image is copyright of its original author

*This image is copyright of its original author

https://www.facebook.com/sergey.bears?fref=nf


STP biologists radio-collared a male tiger nicknamed 'Misha' (Dima, Dale, M20) who habitually hunted adult female brown bears, as well as other bears. Over 80% of Misha's kills found by biologists were bears. 'Misha' killed at least 4 adult female brown bears on record (see chapter 19 study), and two of the four female brown bears killed by 'Misha', were large bears around his own weight:

*This image is copyright of its original author

https://www.nfwf.org/sites/default/files...056.03.pdf

This account, again, confirms that tigers hunt and kill large adult bears of similar-size and weight, and usually have no problems in doing so.

Adult male black bears and adult female brown bears are regularly hunted and killed by male tigers. In some areas and districts, bears are more important in the diet of tigers than wild boar and red deer, particularly during the summer and autumn months. When hunting Himalayan black bears, tigers readily prey on large mature male bears, and when hunting brown bears, tigers also predate on the largest and healthiest adult female brown bears (Kerley).

Linda Kerley's observations on tigers hunting bears:

Back in 2011-2012, a poster named 'Jungle Sprout' contacted tiger biologist and researcher, Linda Kerley for more info on tiger predation on bears, and to know more about her experiences on the topic, and this is what she stated: ( I just posted the text of her email, as the email is in very bad quality and barely readable ) ....

"I have been studying tiger food habits for the past 14 years and have found several bears killed and eaten by tigers. Some tigers specialize in eating bears and they will kill both Asiatic black bears and larger brown bears. We radio tracked one male tiger who ate bears all summer and lost weight in the winter presumably because he couldn't find his favorite food. I have also tracked tigers in snow who seemed to be searching for bear dens perhaps to find a sleeping bear to eat. Recently, people have been killing more bears because of an increased demand for bear feet and gall bladders and I worry that this will effect tigers as well because bears are an important food source for tigers in summer. 

Her reply to his second question: 

"I've seen tigers prey on all shapes and sizes of black bears and up to the largest and healthiest female brown bear. We used to think that only male tigers would be brazen enough to tackle a bear but I have seen one incidence where an adult female tiger with cubs killed and ate a black bear. Bears will kill tiger cubs if they can catch them and will chase mother tigers with cubs off kills. There are many stories and mostly what we know is that there are no rules - anything can happen between bears and tigers."

Note; more recent studies (2015-2017) from Linda Kerley & Dale Miquelle, shows that tigers regularly hunt and kill bears during the summer months, and predate on bears far more often than previously assumed.

Here's some images/videos of adult male Himalayan black bears and female Ussuri brown bears, to put things into perspective of what size and kind of bears that are often hunted by tigers in the Far East of Russia.

Adult male Himalayan black bear in the Lazovsky Reserve: (Primorye region)

*This image is copyright of its original author

Female Ussuri brown bear in the Durminskoye Game Reserve:  (Khabarovsk region)

*This image is copyright of its original author

https://www.facebook.com/amurtigercenter...0194942173


An adult female Ussuri brown bear from "Land of the Leopard" National Park in Primorsky Krai:

*This image is copyright of its original author

As these images & videos clearly show, the bears that are regularly hunted and killed by Amur tigers are large, robust and powerful animals.


Conclusions:

Research shows that tigers prey on large bears, as confirmed and reported by numerous biologists, zoologists and researchers. And do kill large bears with a bite to the base of the skull. Recent sources (Dunishenko, Aramilev, 2021) also confirms this. Its an indisputable fact that Amur tigers hunt and kill large bears. (Kerley, Batalov, Matyushkin, Baikov, Dunishenko, Tkachenko, Rakov etc)

When tigers prey on large bears, quite often these attacks turn into face-to-face confrontations, in which the tiger, in most cases, still ends up killing and devouring the bear. Ambushing large, powerful and robust carnivores of similar size (or heavier) is a dangerous game, but the tiger is a master at it and prevails in most fights.

According to Tkachenko's studies & observations (see Tiger predation on Bears - PART 1) tigers routinely hunt adult (both sexes) Himalayan bears, and individuals of all ages and genders are killed and eaten by tigers. This is also confirmed by Sergey Kolchins recent observations. Tkachenko also observed and reported that male tigers more often hunted large adult brown bears.

Evidence clearly shows that both male and female tigers prey on adult bears of similar size and heavier bears, which refutes the false assumption of tigers only hunting "smaller" bears. Its a fact that tigers predate on bears of many sizes, from large, medium to small. 

Not only did biologist Linda Kerley confirm that tigers hunt and kill the largest and healthiest female brown bears, but she also stated that she's seen tigers prey on all shapes and sizes of black bears, which clearly indicates that she's also seen the largest black bears hunted and killed by tigers.

Renowned Russian biologist & zoologist, Matyushkin also stated that large bears are prey for male tigers.

Tigers are big game hunters, they prefer to hunt large animals. Because so much energy is spent locating prey and killing it, hunting large animals is more efficient than hunting smaller ones. By doing this, tigers maximize their energetic return. Large animals provide more meat for the tiger, thats why male tigers in particular, often hunt and kill large bears, which provide more meat than a small bear.

All in all, it would be completely illogical and ignorant to deny the fact that tigers hunt and kill large brown and black bears. Evidence, accounts and testimonies from various experts & biologists confirms that they do. Reply