There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
01-01-2019, 10:22 PM( This post was last modified: 01-01-2019, 10:25 PM by peter )
PHOTOGRAPHS OF NEPAL TIGERS (2014)
Nepal, directly north of India, is not a very prosperous nation. In spite of that, it's doing very well in the department of conservation. Make that great. It now has over 200 tigers, an achievement only few dreamt of a few years ago!
A year or two ago, I posted a number of tables on the size of tigers in Nepal and different regions in India. The tables were based on information collected before 1940. The conclusion was that Nepal tigers, and those of Royal Chitwan in particular, topped the table for length and weight. Male tigers just about averaged 10 feet in total length measured 'over curves'. Those in Chitwan were even longer.
Tigers living in the hills just south of the Himalayas most probably always had been large. The difference in size between tigers in northern India and Nepal before 1940 could have been a result of protection. In northern India, they were hunted. In Nepal, they were not.
Are Himalayan tigers as large as they were before 1940? Based on what I found in books and documents published after 1940, I'd say they are. The difference in size between tigers in northern India and Nepal most probably is more limited than before 1940. The reason is that tigers are now protected in India as well.
Can you estimate the size of a big cat using a photograph? The answer is negative.
In spite of that, it would be nice to see recent photographs of Nepal tigers in order to get an idea. A few weeks ago, a new member, 'Greenforest', posted a document that has photographs of most, if not almost all, Nepal tigers. Here's the link to the document:
01-04-2019, 09:05 AM( This post was last modified: 01-04-2019, 09:15 AM by Wolverine )
Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
01-04-2019, 08:47 PM( This post was last modified: 01-10-2019, 06:06 AM by peter )
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying most of these statements are untrue. I'm also not saying that large bears would be unable to displace male tigers. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 12 were killed by adult male tigers. The other 3 (all Himalayan black bears, including an adult male) were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer. In the Sichote Alin Nature Reserve, most bears were killed in autumn.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
01-05-2019, 04:13 AM( This post was last modified: 01-05-2019, 05:16 AM by Wolverine )
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
-True, on the chart with No 3 is shown Land of Leopard NP, the only big protected area in Ussuriland situated outside Sihote Alin mountain range close to Chinese Mandzuria, all others are in Sihote Alin. Actualy seeng a maps from your previous posts could say that Jankovsky headquarters were somewhere in the general aria of current Land of Leopard NP, close to the borders with Korea and China.
- Yes, obviously displacing of tigers from brown bears in not something common. Some brown bears sometimes displace tigers while the majority of brown bears in the majority of time do not do this.
- Displacing of tiger from its kill by brown bear for sure is more risky job than displacing of wolf pack even large wolf pack in its combine numbers is not weaker than solitary tiger. In same time appropriating of kill from wolves doesn't mean that the bear will be capable to maintain the possession of the kill for long time since wolves re-group and often start harassing the bear by quick bites, frustrate it and sometimes succeed to chase it away. Here the question is the path of behavior of brown bears. Brown bear is omnivorous animal, it can wonderfully survive eating only vegetarian food and rodents. But sometimes some brown bears suddenly decide that they need meat proteins. Its like a pregnant woman who suddenly is obsessed by pattionate desire to eat some weird food, for example crunchy acidous cucumbers and you have to supply them right a way because her body (physicians says) need these minerals for better development of the embryo...
01-05-2019, 07:14 AM( This post was last modified: 01-05-2019, 07:59 AM by Shadow )
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
About 05: "05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is."
It is told there, that:
Of the nine brown bears that were eaten by tigers, there was one adult male (the tiger acted as the scavenger), one male aged 3-4 years (before the life of the tiger), six adult females (five of them were the victims of the tiger ) and one bear cub of indeterminate sex of the second year of life (hunted by a tiger). Of the eight Himalayan bears that were all victims of tigers, there were two adult males, one adult female and five animals with non-defined sex (two young and three adults). Eight times bears were harvested by adult males of tigers (five times tigers mined brown bears and three – Himalayan), once a brown bear was hunted by a male tiger, whose age is not known, three times the bears were caught by adult females of tigers (an adult female of the Himalayan bear, an adult Himalayan bear of indeterminate sex and a young Himalayan bear AH-indeterminacy lennogo sex) ivtreh cases floor ivozrast ti Grove, dobyvshih a brown bear idvuh rod-Malayan bears was unknown. Five bears (three adult females of a brown bear, one brown bear of the second year of life, and one young Himalayan bear) were harvested by one tiger, an adult, radio-labeled resident male. The adult tigress ate an adult female of a brown bear, shot by a poacher, and a young tiger used an adult male of a brown bear killed by another brown bear.
Sorry for the bad quality of translation, google translate isn´t so easy always :)
Anyway: Male tigers killed there 6 brown bears and if I understood right in one case age of male tiger wasn´t sure, so it might have been adult or subadult, no-one knows obviously. Other 5 cases were by adult male tigers. So it leaves 2 open cases out of eight.
Then again it is told, that one female bear eaten by tigress was killed by a poacher and one young tiger ate carcass of brown bear killed by another brown bear. So when we have 9 dead brown bears and 2 killed by other reasons, than tigers, we have left 7 cases. 6 have been told to be killed by adult male tigers and in one case age of male tiger is unknown. These figures leaves us 1 case of brown bears with no information about cause of death.
9 brown bears: 1 killed by poacher, 1 killed by another brown bear, 6 killed by male tigers, 1 no information. One interesting thing is, that 4 of these killed brown bears were told to be killed by one adult male tiger alone.
What comes to Himalayan black bears, 3 of them were killed by adult male tigers and 3 by tigresses. 2 cases are then without information.
So this information doesn´t give any new information really what comes to brown bears and which tigers hunt those, but shows clearly, that smaller black bears are obviously available to female tigers too. But looks like to be safe to assume (until proven otherwise), that adult male tigers hunt female brown bears and if male bears, young ones or cubs.
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Peter, your posting 1 870 with report: Interspecific relationships between the Amur tiger (Panthera tigris altaica) and the brown (Ursus arctos) and Asiatic black bears (Ursus thibetanus) - I
In your posting isn´t at all page 3/10. You have there 2/10 and next is 4/10. That is the reason you seem to miss some information. I translated whole original document with google translator and there is more about those cases in original document, than there is in that which you have.
And I also think, that when we have open cases, we can´t assume automatically, that female tigers killed those bears. We simply don´t know what happened, when researchers don´t know either.
01-05-2019, 08:41 AM( This post was last modified: 01-05-2019, 08:50 AM by peter )
(01-05-2019, 07:37 AM)Shadow Wrote:
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Peter, your posting 1 870 with report: Interspecific relationships between the Amur tiger (Panthera tigris altaica) and the brown (Ursus arctos) and Asiatic black bears (Ursus thibetanus) - I
In your posting isn´t at all page 3/10. You have there 2/10 and next is 4/10. That is the reason you seem to miss some information. I translated whole original document with google translator and there is more about those cases in original document, than there is in that which you have.
And I also think, that when we have open cases, we can´t assume automatically, that female tigers killed those bears. We simply don´t know what happened, when researchers don´t know either.
Your response to my last post was the reason I read the article again. When I noticed that page 3 was missing, I logged in to inform you. But you beat me to it. Excellent reading and many thanks!
Why such a basic error? As a result of the amount of info on tigers and bears published in the last years, I decided to reorganize the entire administration. Everything I have is on my table and it's a lot. Page 3 no doubt is somewhere, but I would appreciate you posting the page as I'm very busy at the moment. Thanks in advance.
I don't know if the situation in the Sichote-Alin Nature Reserve is typical for all reserves in the Russian Far East, but if we assume it could be, the conclusion is that about 80% of all bears killed is killed by male tigers (12 out of 15). If we know the number of bears killed by male tigers, we have to add 25% to find the total number of bears killed by tigers.
When we want to find out how many bears (both species) are killed by tigers every year, we need to start with the number of male tigers. Not all of them hunt bears. Based on the info from the Sichote-Alin Nature Reserve, it's likely that some of them are specialists. This is what Tkatchenko (2012) found in the reserve in the northern part of Sichote-Alin and the situation in the Sichote-Alin Nature Reserve seems to be similar in this respect. My guess is it isn't very different in tigresses, as it takes a lot of skill to hunt a bear.
In the Sichote-Alin Nature Reserve, tigers hunt quite large bears. The table in the article of Kerley et al. (2015) I posted says tigers hunt bears more often in the southern part of Sichote-Alin. Based on the info provided by Olga, tigers kill quite many young bears in the south. So much so, that female brown bears left districts with experienced bear hunters. This means that the average weight of bears killed in the southern part of Sichote-Alin most probably is lower than in the Sichote-Alin Nature Reserve. Biomasswise, however, bears still are an important source of food in the south. More so than in the Sichote-Alin Nature Reserve. This most probably means they not only hunt cubs, but larger bears as well.
Although it's likely that tigers kill a few hundred bears every year in the Russian Far East, the effect of predation, percentagewise, most probably is very limited. The reason is the number of bears in regions inhabited by tigers. In some districts in the southern part of Sichote-Alin, however, the pressure could be relatively heavy.
01-05-2019, 12:22 PM( This post was last modified: 01-05-2019, 12:26 PM by Greatearth )
It might be out of topic, but I think tigers and bears would generally avoid each other.
The Bengal tiger, Indochinese tiger, Malayan tiger, Sumatran tiger, Javan tiger, and Bali tiger once faced with the saltwater crocodile, which is the most dangerous rival equivalent as the brown bear. It is still occurring in smallest mangrove swamp forest Bengal tigers in the Sundarbans and the Sumatran tigers in some area. Not sure of the Malayan tiger since saltie is almost extinct in Indochina.
I heard that saltwater crocodiles in Sundarbans normally leave the tigers alone even when they are swimming in water because tigers can injure them horribly. Idk where did this person got this information, but I remember reading it from comment by Indian living in Sundarbans area. Wouldn't be the same for bear vs tiger?
01-05-2019, 12:40 PM( This post was last modified: 01-05-2019, 01:12 PM by Wolverine )
(01-05-2019, 08:41 AM)peter Wrote:
(01-05-2019, 07:37 AM)Shadow Wrote:
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Peter, your posting 1 870 with report: Interspecific relationships between the Amur tiger (Panthera tigris altaica) and the brown (Ursus arctos) and Asiatic black bears (Ursus thibetanus) - I
In your posting isn´t at all page 3/10. You have there 2/10 and next is 4/10. That is the reason you seem to miss some information. I translated whole original document with google translator and there is more about those cases in original document, than there is in that which you have.
And I also think, that when we have open cases, we can´t assume automatically, that female tigers killed those bears. We simply don´t know what happened, when researchers don´t know either.
Your response to my last post was the reason I read the article again. When I noticed that page 3 was missing, I logged in to inform you. But you beat me to it. Excellent reading and many thanks!
Why such a basic error? As a result of the amount of info on tigers and bears published in the last years, I decided to reorganize the entire administration. Everything I have is on my table and it's a lot. Page 3 no doubt is somewhere, but I would appreciate you posting the page as I'm very busy at the moment. Thanks in advance.
I don't know if the situation in the Sichote-Alin Nature Reserve is typical for all reserves in the Russian Far East, but if we assume it could be, the conclusion is that about 80% of all bears killed is killed by male tigers (12 out of 15). If we know the number of bears killed by male tigers, we have to add 25% to find the total number of bears killed by tigers.
When we want to find out how many bears (both species) are killed by tigers every year, we need to start with the number of male tigers. Not all of them hunt bears. Based on the info from the Sichote-Alin Nature Reserve, it's likely that some of them are specialists. This is what Tkatchenko (2012) found in the reserve in the northern part of Sichote-Alin and the situation in the Sichote-Alin Nature Reserve seems to be similar in this respect. My guess is it isn't very different in tigresses, as it takes a lot of skill to hunt a bear.
In the Sichote-Alin Nature Reserve, tigers hunt quite large bears. The table in the article of Kerley et al. (2015) I posted says tigers hunt bears more often in the southern part of Sichote-Alin. Based on the info provided by Olga, tigers kill quite many young bears in the south. So much so, that female brown bears left districts with experienced bear hunters. This means that the average weight of bears killed in the southern part of Sichote-Alin most probably is lower than in the Sichote-Alin Nature Reserve. Biomasswise, however, bears still are an important source of food in the south. More so than in the Sichote-Alin Nature Reserve. This most probably means they not only hunt cubs, but larger bears as well.
Although it's likely that tigers kill a few hundred bears every year in the Russian Far East, the effect of predation, percentagewise, most probably is very limited. The reason is the number of bears in regions inhabited by tigers. In some districts in the southern part of Sichote-Alin, however, the pressure could be relatively heavy.
So, if I understood your posts properly tigers has killed 15 bears for 2 decades from 1992-2013 in Sihote Alin state reserve. Tiger population of this reserve consist of 15-20 adult tigers or 3% of all wild Amur tigers. If we assume same frequency of killings for entire RFE we have to multiply 15 X 33 = 495 bears for 2 decades in entire Ussuriland. That means that according possibility theory tigers kill as average 24-25 bears annually in entire RFE. If we assume that southern parts of the region tigers hunt bears 2 times more frequently this makes 48-50 bears annually.
In same time you write about 18 cases of tigers displaced by brown bears in Sihote Alin state reserve for same period -1992-2013 or 0,8-0,9 per year. For entire RFE that mean 30 displacements per year or 600 per 2 decades. 18 is more than 15 hence brown bears displace tigers a little bit mote often than tigers kill bears.
01-05-2019, 09:07 PM( This post was last modified: 01-05-2019, 09:55 PM by ShadowEdit Reason: Addition.
)
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Here is something about 07: "07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013."
Here is another study (looks like to be overall of whole population) about mortality of Amur tigers 1985-1996. This study is partially overlapping with Sikhote-Alin report what comes to timeline. I have to say, that human caused death numbers were shocking in a way to realize, when we know how small number of tigers there is... But this report isn´t in contradiction with that, what Peter wrote. This report is from all population, not only from Sichote-Alin Nature Reserve. I haven´t seen more recent report yet about all Amur tiger population.
01-06-2019, 05:49 AM( This post was last modified: 01-06-2019, 09:29 AM by Wolverine )
(01-05-2019, 09:07 PM)Shadow Wrote:
(01-04-2019, 08:47 PM)peter Wrote:
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Here is something about 07: "07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013."
Here is another study (looks like to be overall of whole population) about mortality of Amur tigers 1985-1996. This study is partially overlapping with Sikhote-Alin report what comes to timeline. I have to say, that human caused death numbers were shocking in a way to realize, when we know how small number of tigers there is... But this report isn´t in contradiction with that, what Peter wrote. This report is from all population, not only from Sichote-Alin Nature Reserve. I haven´t seen more recent report yet about all Amur tiger population.
Very interesting Shadow. Where did you dig out this paper? If I am not wrong Its written that for the period 1985-1996 in entire RFE totaly 7 tigers have been killed by bears and 4 tigers have been killed by wild boars. But this data is for entire Russian Far East while the paper posted by Peter was only for Sihote Alin state reserve which is unsignificant percentage of Ussuriland teritory. So, there is no any contradiction.
(01-04-2019, 09:05 AM)Wolverine Wrote: Reason for scavenging of wolf kills by brown bears which probably could be applied for the brown bears and tigers as well:
"Additionally, grizzly bears now take advantage of the predatory behavior of wolves by waiting for the wolves to finish hunting and then contesting the wolves for access to the carcasses of their kill (Smith et al., 2003). As a result of being the larger animal in these standoffs, bears usually win, giving them access to food without the work involved in actually tracking down and killing the prey themselves (Smith et al., 2003). In addition to the obvious benefit of being able to consume this food, the grizzly bear populations do not have to expend the energy to hunt, as they now have a species that virtually does the hunting for them (Smith et al., 2003)."
Yes, read that one some years ago. It's no doubt true regarding brown bears and wolves in the northern part of the Americas. Same for bears and pumas. There is, however, a difference between wolves, pumas and tigers.
AUTHORITIES ON BEARS AND TIGERS IN THE RUSSIAN FAR EAST- RECENT PAST (1900-2010)
Over the years, I've read quite a bit on tigers and bears in the Russian Far East. Most authorities agreed that large bears displaced tigers more or less at will (1). Although they admitted that tigers hunt more bears than the other way round, that mainly was a result of tigers deciding when to hunt what bears where (2). Tigers, of course, decided for cubs most of the time (3). If they took a largish bear, it was a result of an ambush (4). In a one-on-one in non-ambush conditions, bears, if of similar size, would previal more often than not (5). Even large females came at quite a cost (6). Tigers disputing authorities, of course, often paid. No less than 12 perished in fights with bears over the years (7). All in all, they agreed that bears were 'too dangerous' to hunt for tigers (8). Etc.
I'm not saying large bears would be unable to displace male tigers. I'm also not saying that tigers and bears is a one-sided affair. Recent research, however, says it's about time to redefine a few statements that survived the ages.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - DISPLACEMENT
A few weeks ago, an interesting document ('Interspecific Relationsships Between the Amur Tiger (Panthera tigris altaica and the Brown Bear (Ursus arctos) and Asiatic Black Bears (Ursus thibetanus', Seryodkin et al., 2017) was discussed in this thread.
In the period 1992-2013, researchers found 763 animals eaten by tigers. Of these, 378 were eaten in the period that bears were not hibernating. In 11 of these 378 cases (2,91%), tigers were displaced, whereas bear and tiger shared in 7 cases (1,85%). Tigers lost, or partly lost, 4,76% of their kills to bears. Less than 1 in 20, that is.
In the 11 cases of displacement (in one of them an adult male Himalayan black bear was involved), bears displaced tigresses (in one case, the gender of the tiger was unknown). Of the 7 tigers forced to share their kill with bears, 1 was an adult male tiger.
All in all, we're talking about 18 cases in which tigers were displaced by bears or forced to share in the period 1992-2013. Less than once a year. And 'tigers' turned out to be tigresses in nearly all cases.
TIGERS AND BEARS IN THE SICHOTE-ALIN NATURE RESERVE 1992-2013 - TIGERS HUNTING BEARS
In the period 1992-2013, 8 Himalayan black bears and 9 brown bears were eaten by tigers. Of the 9 brown bears, 2 (an adult male and an adult female) were not killed by tigers. Of the other 7, two ranged between 1-4 years of age. The others were adult females. Of the 8 Himalayan black bears, 2 were young adults. The others (males and females) were adult.
Tigers killed less than 1 bear a year in the Sichote-Alin Nature Reserve in the period 1992-2013, that is. Of the 15 they killed themselves, 2 (brown bears) were immature. All others were adults.
Which tigers hunt bears? Of the 15 bears killed by 'tigers', 8 were killed by adult male tigers. The other 7, therefore, most probably were killed by adult tigresses.
TIGERS AND BEARS IN 3 SITES IN THE RUSSIAN FAR EAST - TIGERS HUNTING BEARS
Of the 378 animals eaten (and most probably killed) by tigers in the period that bears were available, 15 (3,97%) were bears (both species). In the Sichote-Alin Nature reserve, the conclusion is that tigers are modest bear hunters.
According to Kerley et al. ('A Comparison of Food Habits of Amur Tiger (Panthera tigris altaica, Temminck, 1844) at three sites in the Russian Far East', 2015), bears are more often hunted in the south of Sichote-Alin. Corrected for pseudo-replication, the percentages are quite high:
*This image is copyright of its original author
Remember that the percentages refer to biomass, not the number of animals killed by tigers. Also remember that most bears were hunted in summer, not winter.
Here's the map in the article of Kerley et al. There is some confusion about the location of the Sichote-Alin Nature Reserve. It's the reserve in the northeastern part of Sichote-Alin (no. 1 on the map below). In the map, that reserve is the Southwest Primorskii Krai (SW).
My guess is a mistake was made. Same for the percentages in that 1 was 3 and the other way round:
*This image is copyright of its original author
CONCLUSIONS
The info in this post is without the observations of K.N. Tkatchenko ('Peculiarities of nutrition of the Amur tiger Panthera tigris altaica (Carnivora, Felidae) in a densely populated locality (on the example of the Bolshekhtsirsky reserve and its environs'), 2012). The tigers he studied in the northwestern part of Sichote-Alin were heavily involved in bears.
Based on these 3 studies published in 2012, 2015 and 2017, we can get to a number of conclusions. One could say that each of them debunks an assumption close to a myth and be close.
01 - Although tigers in the Russian Far East are wild boar hunters foremost, bears are an important food source. Biomasswise, bears are as important as wild boars in some regions.
02 - Most bears are not hunted in winter, as many assume, but in summer.
03 - Tigers in the Sichote-Alin Nature Reserve (situated close to the coast) are modest bear hunters: about 4% of all animals killed in the period 1992-2013 are bears. In reserves in the northwestern, southeastern and southwestern part of Sichote-Alin, the percentages are (significantly) higher.
04 - In the Sichote-Alin Nature Reserve, brown bear cubs (< 1 year of age) were not hunted in the period 1992-2013. Two of the 7 brown bears killed ranged between 2-4 years of age. The other 5 were adult females, averaging 140-150 kg. Of the 9 Himalayan black bears killed, 2 were young adults. The other 7 were adult. Of the 15 bears killed (both species), 11 were adult, whereas two (Himalayan black bears) were young adults. One of the two immature brown bears killed a was 3-4 year old male. Based on the info I have on the size of immature male brown bears, the bear could have been as heavy as his killer, if not heavier.
05 - Many assume that bears, and brown bears in particular, are hunted by adult male tigers only. In the Sichote-Alin Nature Reserve, however, 8 of the 15 bears hunted in the period 1992-2013 were killed by adult male tigers. The other 7 bears were killed by young adult male tigers or adult tigresses, that is.
06 - In the Sichote-Alin Nature Reserve, tigers killed 378 animals in the period bears were not hibernating. Bears displaced tigers in 11 cases (2,91%). In 7 cases (1,85%), tiger and bear shared the kill. Tigers lost, or partly lost, less than 5% of their kills to bears, that is. Less than 1 in 20. This in a period of 21-22 years. And 'tigers' turned out to be tigresses in all but one case (in which an adult male tiger shared his kill with a brown bear).
07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013.
08 - Based on 1-7, one can't, as some did, conclude that (brown) bears are 'too dangerous' to hunt. Tigers avoid adult male brown bears, but adult females " ... up to the largest and healthiest individuals ... " (Kerley, 2011) are hunted more often than many apparently assume.
Kerley's observation is supported by those of Bart Schleyer, who followed tigers in the snow. Most of them were older males, who had about a hundred pounds on the bears they followed. All bears were killed and all were killed with a bite to the base of the skull.
Recent observations suggest that the largest female brown bears killed by male tigers ranged between 150-200 kg. One of the male tigers was injured during the fight.
09 - According to those who know, adult males of both species avoid each other. Although most favor the bear in a fight, male tigers were not displaced by brown bears in the Sichote-Alin Nature Reserve in the period 1992-2013.
10 - In recent articles, researchers said 12 tigers have been killed by brown bears in fights. In 10, adult tigresses and youngish male tigers (adolescents and young adults) were involved. I know of two cases in which adult male tigers were killed by bears. The tiger killed in 1960 was a young adult male. That incident was described more than once. There's no info about the tiger killed in 1972.
Here is something about 07: "07 - In the Sichote-Alin Nature Reserve, no tigers were killed by bears in the period 1992-2013."
Here is another study (looks like to be overall of whole population) about mortality of Amur tigers 1985-1996. This study is partially overlapping with Sikhote-Alin report what comes to timeline. I have to say, that human caused death numbers were shocking in a way to realize, when we know how small number of tigers there is... But this report isn´t in contradiction with that, what Peter wrote. This report is from all population, not only from Sichote-Alin Nature Reserve. I haven´t seen more recent report yet about all Amur tiger population.
Very interesting Shadow. Where did you dig out this paper? If I am not wrong Its written that for the period 1985-1996 in entire RFE totaly 7 tigers has been killed by bears and 4 tigers has been killed by wild boars. But this data is for entire Russian Far East while the paper posted by Peter was only for Sihote Alin state reserve which is unsignificant percentage of Ussuriland teritory. So, there is no any contradiction.
This was posted at the Animal Versus Animal forum of Yuku (now Tapatalk) by Grahh or Warsaw. It could be in the thread 'Male bears are not out of the predatory reach of male tigers if of similar size'. That thread still is a good read for those interested in tigers and bears in the Russian Far East and it isn't the only one.
I agree human-caused mortality was significant in that period of time. Today, things seem to have changed for the better. If the proposals of Pikunov will be implemented, the number of tigers in the Russian Far East can continue to grow, but there's no room for, say, a thousand adult tigers in Sichote-Alin. In China, the situation seems to be more promising in this respect.
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01-06-2019, 09:49 AM( This post was last modified: 01-06-2019, 10:08 AM by Wolverine )
I remember that as a child red in Red book of Soviet Union (from 1980's or 1970's) that even in pre-industrial age, before human colonization of RFE Amur tiger's population was assessed at around 700-900, there were never more than 700-900 wild tigers in what is today Russian Ussuriland. Amur tigers have never been numerous.
That's way we have to understand that there is only one true Kingdom of the Tiger in this planet and this is INDIA. Tropical ecosystems are much more fertile than northern ecosystems, density of tropical tigers is 15-20 larger than dencity of Siberian tigers. In one small Kaziranga NP on territory of 430 sq.km. live 90 tigers while in gigantic Bikin NP with territory of 11 600 sq. km. live only 40-50 tigers....
Every square feet of Indian jungle is teeming with life, every square feet of Indian jungle is a diamond! @Rishi
(01-06-2019, 09:49 AM)Wolverine Wrote: I remember that as a child red in Red book of Soviet Union (from 1980's or 1970's) that even in pre-industrial age, before human colonization of RFE Amur tiger's population was assessed at around 700-900, there were never more than 700-900 wild tigers in what is today Russian Ussuriland. Amur tigers have never been numerous.
That's way we have to understand that there is only one true Kingdom of Tiger in this planet and this is INDIA. Tropical ecosystems are much more fertile than northern ecosystems, density of tropical tigers is 15-20 larger than dencity of Siberian tigers. In one small Kaziranga NP on territory of 430 sq.km. live 90 tigers while in gigantic Bikin NP with territory of 11 600 sq. km. live only 40-50 tigers.
Every square feet of Indian jungle is teeming with life, every square feet of Indian jungle is a diamond! @Rishi
Really? So Siberian tigers were always small numbers in Russia? 700-900 seems to be too small. Wouldn't be just in Ussuriland? How about other states in Russia? Moreover, places like Manchuria? I think Manchuria was once hold the highest populations of the Siberian tigers. Plus, many people also hunts their food like deer a lot in 20th century. Korea had a high density of tigers compared to its size.
I was always wondered that why tiger population was high in India even though they were exceptionally hunted just like in other Asia. It maybe different reasons. I don't know places like other South East Asia (India is also much larger than other SE Asia country). As for biodiversity, Indochina has much higher biodiversity than India. About population of large mammals seem to be different. However, I am curious why prey density in South East Asia is smaller than India.
China once had the Siberian tiger, Caspian tiger, South China tiger, Indochinese tiger, and Bengal tiger. China was also experienced different ecosystems throughout the times due to human impacts throughout each dynasties.
I am not sure how many tigers were in mainland China 100~150 years ago. I believe that Kingdom of Tiger was for both China and India, I would put more hand on China though. Difference is that chinese lost that title by themselves.
01-06-2019, 10:32 AM( This post was last modified: 01-06-2019, 10:35 AM by Wolverine )
(01-06-2019, 10:10 AM)Greatearth Wrote:
(01-06-2019, 09:49 AM)Wolverine Wrote: I remember that as a child red in Red book of Soviet Union (from 1980's or 1970's) that even in pre-industrial age, before human colonization of RFE Amur tiger's population was assessed at around 700-900, there were never more than 700-900 wild tigers in what is today Russian Ussuriland. Amur tigers have never been numerous.
That's way we have to understand that there is only one true Kingdom of Tiger in this planet and this is INDIA. Tropical ecosystems are much more fertile than northern ecosystems, density of tropical tigers is 15-20 larger than dencity of Siberian tigers. In one small Kaziranga NP on territory of 430 sq.km. live 90 tigers while in gigantic Bikin NP with territory of 11 600 sq. km. live only 40-50 tigers.
Every square feet of Indian jungle is teeming with life, every square feet of Indian jungle is a diamond! @Rishi
Really? So Siberian tigers were always small numbers in Russia? 700-900 seems to be too small. Wouldn't be just in Ussuriland? How about other states in Russia? Moreover, places like Manchuria? I think Manchuria was once hold the highest populations of the Siberian tigers. Plus, many people also hunts their food like deer a lot in 20th century. Korea had a high density of tigers compared to its size.
I was always wondered that why tiger population was high in India even though they were exceptionally hunted just like in other Asia. It maybe different reasons. I don't know places like other South East Asia (India is also much larger than other SE Asia country). As for biodiversity, Indochina has much higher biodiversity than India. About population of large mammals seem to be different. However, I am curious why prey density in South East Asia is smaller than India.
China once had the Siberian tiger, Caspian tiger, South China tiger, Indochinese tiger, and Bengal tiger. China was also experienced different ecosystems throughout the times due to human impacts throughout each dynasties.
I am not sure how many tigers were in mainland China 100~150 years ago. I believe that Kingdom of Tiger was for both China and India, I would put more hand on China though. Difference is that chinese lost that title by themselves.
These numbers (700-900) are only for Outer (Russian) Mandzuria and do not include numbers in Inner (Chinese) Mandzuria which is twice the size of the Russian part. Soviet scientists didn't care about China of cource when they did their assesments.
Why the density of tigers is higher in India than in South East Asia if they both are tropical ecosystems? Good question. Its the same question as why the human population in India is so gigantic and much much larger than population of South East Asia? A land which can feed much more people can also feed much more tigers. They both have high tempeartures and high humidity ideal for lush vegetation. The answer is: SOIL. The alluvial soils of India and China are the most fertile soils in the planet. In India you have ideal combination: high temperatures + humidity + fertile soils + enough grass between trees for feeding of high number of herbivores. So you have astronomical dencity of tigers and other big predators.
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
