WildFact
›
Premier Section
›
Edge of Extinction
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
ON THE EDGE OF EXTINCTION - A - THE TIGER (Panthera tigris)
|
 (06-19-2019, 10:57 AM)peter Wrote:(06-19-2019, 05:55 AM)Shadow Wrote: I noticed this article about that extraordinary case, where Siberian tiger Tikhon seemed to seek help. Was it so, that @peter had more information if Tikhon is still alive or dead? No matter how it is, this article has many photos from treatment of Tikhon. Here is footage about sedation of Tikhon. It was still in shape to run, when captured :) 
This is why I don't view tiger subspecies are 2, neither Siberian tiger (Panthera tigris altaica) and Caspian tiger (Panthera tigris virgata) are the same subspecies. It is on The Caspian Tiger #33.
How is it possible that tigers lived in the Korean peninsula (Seoul or Busan) and Russian Far East (Vladivostok) can be the same subspecies as tigers lived in far west of Asia, or few individual tigers reached even far places as western Russia, Belarus, and Ukraine? Whoever did research on that paper just wasted their grant money and published worthless information. However, I can understand that Caspian tigers lived in the central Asia were genetically very similar to Siberian tigers. It still won't cause any problem to releasing Siberian tigers in Central Asia since Caspian tigers are extinct. The same for releasing Sumatran tigers in Java Island, but situation of Java is even worse than Sumatra Island. Bali is absolutely impossible. Sad reality of Asia continent. ![[Image: sad.png]](https://wildfact.com/forum/images/smilies/wasm/sad.png) Few posts (and years) ago I discussed this idea about subspecies vs species. Biologists are still arguing how to define "subspecies". Reptiles, amphibians, fishes, and small birds and mammals are easy to define as species/subspecies since their can't move far wide as large mammals. Animals like tigers are different. That's why biologists are arguing how to define tiger subspecies. Bengal tigers living in western Myanmar/India/Bangladesh are suppose to be more similar to Indochinese tigers in eastern Myanmar compared to Bengal tigers in western/southern India, and Indochinese tigers lived in eastern Myanmar are more similar to Bengal tigers in western Myanmar compared to Indochinese tigers in Thailand, Cambodia, and Laos. Indochinese tigers lived in right above of Malayan Peninsula are definitely more similar to Malayan tigers in northern Malayan Peninsula, while Malayan tigers lived in southern Malayan Peninsula and Singapore Island are probably more closely related to Sumatran tigers. The same for Sumatran tigers, Javan tigers, Bali tigers, South China tiger, and Chinese tigers lived in mainland China. It is very difficult to conclude exact "subspecies" and boundaries in their range map. The same for any other large and medium size animals. That is why some biologists are just view it as 2 subspecies since tigers are endangered. However, I am absolutely against and disagree with 2 subspecies since people will start mixing tigers if it happens. I personally view any biologists believe tiger subspecies are 2 are highly ignorant and nonsense like Kitchner guy. However, I can understand their point of view on 2 tiger subspecies if you study genomic. It is very difficult to defining subspecies on large animals unless they are living in islands. I hope those people are not go far as doing stupid thing like releasing one tiger into places where other tiger subspecies live. (06-23-2019, 09:26 AM)Greatearth Wrote: This is why I don't view tiger subspecies are 2, neither Siberian tiger (Panthera tigris altaica) and Caspian tiger (Panthera tigris virgata) are the same subspecies. It is on The Caspian Tiger #33. Different definitions exist for the term 'subspecies', one of which is that two members of the same species are genetically and geographically distinct from each other (https://www.merriam-webster.com/dictionary/subspecies). If you go by genetics, then either the Caspian and Siberian tigers will have to be treated as the same subspecies, or the Bengal tigers will have to be divided into different subspecies, because the Caspian tiger is more closely related to the Siberian tiger than say a Sundarban Bengal tiger would be to a northern Bengal tiger in northern India, Nepal or Bhutan: Luo et al.: https://journals.plos.org/plosone/articl...ne.0004125 Figure 2. Phylogenetic relationships among tiger mtDNA haplotypes inferred using 4079 bp of concatenated mtDNA sequences (see Table S3). Singh et al.: https://www.ncbi.nlm.nih.gov/pmc/article...8846.g002/ Median-joining network created from four mtDNA genes (cytb, ND2, ND5 and ND6) (in total, 2600 bp) depicting genetic relationship between all haplotypes found in tigers. (a) haplotypes found in Sundarbans tigers (in black) and all other six tiger subspecies (in yellow and green color, from Luo et al. 2004) [2], (b) all haplotypes found in Bengal tiger populations from this study and Mondol et al. [22]. Pink: North India, Yellow: Central India, Blue: South India, and Green: Sundarbans. The sizes of the circles are proportional to the haplotype frequencies. Sundarban Bengal tiger: https://commons.wikimedia.org/wiki/File:..._Tiger.jpg Northern Bengal tiger at Jim Corbett National Park, northern India: https://www.dhikalaforestlodge.in/cobett...-park.html Stuffed Caspian tiger from Iran which was killed after attacking livestock near Tbilisi in what is now Georgia, South Caucasus: http://kavehfarrokh.com/iran-and-central...the-1930s/ Amur tiger: http://overpoise.com/amur-tiger.html/amu...ter-forest If you go by climatological differences, this is where things can get complicated because there are both similarities and differences between Amur and Caspian tigers, like there would be between Himalayan Bengal tigers and Bengal tigers in hot jungles. On one hand, the temperate region inhabited by the Siberian tiger is different to the reed thickets of Central Asia or the tugai forests of West Asia, especially that surrounding the interesting river called 'Tigris' in Mesopotamia (mostly Iraq, but with parts of what are now Syria and Turkey), and so: Caspian tiger hunted by Soviet soldiers in a reed thicket of Central Asia, probably near the River Panj, in the early 1930s: http://kavehfarrokh.com/iran-and-central...the-1930s/ The Tigris River near Mosul in Iraq, roughly where a tiger, possibly from southeastern Anatolia (Turkey), was shot in 1887 (https://www.tandfonline.com/doi/abs/10.1...0.10637583): https://commons.wikimedia.org/wiki/File:TigrisRiver.JPG On the other hand, both the Caspian and West Siberian tigers appear to have occurred in the region of Lake Baikal in eastern Siberia (https://archive.org/stream/mammalsofsov2...rch/Baikal), and even apart from that, the Caspian tiger would have inhabited fairly temperate regions, such as northern Iran and the Caucasus, compared to the hot jungles of South and Southeast Asia, except that the Himalayan region of South Asia, where the Bengal tiger is present, is also fairly temperate: Map of distribution of tiger subspecies by Vratislav Mazák, page 3: https://web.archive.org/web/201203091255...1-0001.pdf Lake Baikal in south-central Russia, north of Mongolia: https://www.livescience.com/57653-lake-b...facts.html Caspian tiger killed in northern Iran in the 1940s: http://www.tigers.ca/Foundation%20overview/caspian2.htm A Persian leopard in the snow at Golestan National Park, northern Iran, where the country's last known tiger were sighted in the 1950s (https://books.google.com/books?id=t2EZCS...&q&f=false): https://www.earthtouchnews.com/conservat...ast-stand/ Himalayan Bengal tiger in the snow at Bhutan: https://www.iucn.org/news/species/201707...ers-bhutan
BorneanTiger
Sorry, but I have no idea what is your conclusion. So what is your conclusion? If you can read gene sequence (1st photo) and haplotype/mtDNA (2nd photo), then explain it to me precisely about those two pictures that how does it defines tiger subspecies. And again, where did samples on Caspian tiger samples came from for their research? Don't tell me if those Caspian tiger samples are from central part of Asia. If Malayan tiger is separate species from Indochinese tiger, then how is it possible for you to believe Caspian tiger lived in westernmost of Asia can be the same as Siberian tiger lived in southern part of the Korean Peninsula? I even seen worse idiotic biologist from the Texas A&M are saying like, "From our research, we discovered that every big cats were evolved from mixed each other throughout the history." Can you believe that now? That's why I am always having doubt on genetic opinion on species vs subspecies sometimes, especially if it is about big cats or other large mammals. They are just wasting grant money, including ones who published papers on single tiger species. They should better study on how to increase genetic variations from genetic bottleneck. Yes, Siberian tiger and Caspian tiger are closely related subspecies. I don't think it won't cause problem to releasing Siberian tigers into Caspian tiger range map. However, I can never agree that those two were the same subspecies unless they are referring to Siberian tigers lived in northern part of their range and Caspian tiger lived in the central Asia. (06-23-2019, 09:50 PM)Greatearth Wrote: BorneanTiger To put it simply, if you want to treat the Caspian and Siberian tigers as separate subspecies, then the Bengal tiger shouldn't be treated as a single subspecies, but a group of subspecies, such as perhaps Sundarban and Himalayan Bengal tigers, but if you want to treat the Bengal tiger as a single subspecies, then the Caspian and Siberian tigers will have to be treated as the same subspecies, because the Caspian tiger is more closely related to the Amur tiger than a Sundarban Bengal tiger is to a Himalayan Bengal tiger. Luo et al. tested wild Caspian tigers from China, Afghanistan and the Central Asian countries of Kazakhstan and Uzbekistan, besides a captive tiger in Moscow Zoo that was taken in the wilderness in northern Iran in West Asia, before coming to the conclusion that Caspian and Siberian tigers were closely related, so there you go, even Caspian tigers in West Asia were closely related to Amur tigers in Northeast Asia: https://journals.plos.org/plosone/articl...ne.0004125 *This image is copyright of its original author Figure 2. Phylogenetic relationships among tiger mtDNA haplotypes inferred using 4079 bp of concatenated mtDNA sequences (see Table S3). To compare, the closest relatives of Bengal tigers in the Sundarbans appear to be southern Indian tigers and a number of central Indian tigers, with Bengal tigers in northern India being genetically different to them in a significant manner, see the diagram on the right-hand side: https://www.ncbi.nlm.nih.gov/pmc/article...8846.g002/ *This image is copyright of its original author Median-joining network created from four mtDNA genes (cytb, ND2, ND5 and ND6) (in total, 2600 bp) depicting genetic relationship between all haplotypes found in tigers. (a) haplotypes found in Sundarbans tigers (in black) and all other six tiger subspecies (in yellow and green color, from Luo et al. 2004) [2], (b) all haplotypes found in Bengal tiger populations from this study and Mondol et al. [22]. Pink: North India, Yellow: Central India, Blue: South India, and Green: Sundarbans. The sizes of the circles are proportional to the haplotype frequencies.
BorneanTiger
That logic is absolutely wrong, and that's why I view biologists brought up/published single species are extremely ignorant. They just think one stuff and something that is right front of them, but they can never think something that is far away. That's why I said they should never allow to work on tigers in Asia since they will ruining important evolutionary process caused naturally since thousands years ago. It was exactly like when many physicists living in the early 1900s were against with Einstein's special relatives and gravity waves. Or many physicists attacked on Boltzmann during the mid and late 1800s since they never believed his ideas on atom and thermodynamics. Now, we already know Einstein and Boltzmann were correct. I've seen this from Korean biologists working on reintroducing moon bear since past 20 years. Distance of South Korea to Caucaus mountain vs Himalaya to southern India? Your conclusion is no different than Bengal tigers living in Sundarbans or rainforest in western Myanmar are treated as the same subspecies as Malayan tiger living in rainforest or swamp in the Malayan Peninsula. I know you kindly provide info/photo on Caspian tigers, but I already know and seen photo, specimen, and morphology difference of Caspian tigers in different part of Asia long before someone post in wildfact. The same for Bengal tigers in different parts of habitats. And why did you brought up subspecies distinguish on Caspian tiger vs Bengal tiger in Sundarban and Himalaya to comparing Siberian tiger with Caspian tiger? We all already know Caspian tiger and Bengal tigers were far away from each other. That explanation is absolutely irrelevant. You can't compare any other tiger subspecies to Caspian tigers beside Siberian tigers. You also need to understand that tigers in India are mostly staying in the same place (isolated from long time) unlike the past due to human activity. And when I read that paper again, those biologists clearly mentioned they did not tested Caspian tigers from the westernmost part of Asia. I didn't said copy and paste photos and statements from paper. Explain it to me about haploid or mtDNA genes (cytb, ND2, ND5 and ND6), and other things in that paper that how does it shows tiger subspecies.. You studied and understand genomic/genetic. So explain it to me how does it shows they can be the same or different subspecies. You don't have to since you can believe whatever you want. Until 3-4 years ago, biologists believed lion and jaguar are the most closely related species. However, recent paper published concluded that leopard is actually most closely related to lion.. We will never know until the future. We don't really know everything on genomics, and this field is one of the fastest changing/studying area in biology. We should never conclude anything from our knowledge yet unlike like biologists brought up all tigers in mainland Asia are the same.
@
(06-23-2019, 09:26 AM)Greatearth Wrote: This is why I don't view tiger subspecies are 2, neither Siberian tiger (Panthera tigris altaica) and Caspian tiger (Panthera tigris virgata) are the same subspecies. It is on The Caspian Tiger #33... Absolutely! Even if they're considered similar enough to be a single subspecies, Siberian & Caspian tigers lived far enough as well as segregated enough from each other to have significant genetic differences. Like bengal tigers from different regions of India (for example, something like ranthambore's tigers compared to rest of central India's). In India the Satkosia relocation was done with tigers from Madhya Pradesh, 500km away. That was because of higher historical genetic similarity between both Bengal tigers populations from the two areas, compared to other adjoining places (maybe because of natural connection by a thick forest tract along Mahanadi river basin). Similar must be done for Amurs too... Tigers from Korean peninsula, Russian Far East, Manchuria, Central Asia could have had unique genetic differences. "Subspecies" are a man-made concept. Even if humans decide the similarities are/not enough for two populations to be classified as same subspecies, the natural variations within would still be there & needs to be preserved as well. Only few years ago Malayan tigers were decided to be different enough to be declared a seperate subspecies from Indochinese ones, after genomic study. Those differences still continue to exist & you can't just release tigers from Myanmar or Manchuria in those places just because they're broadly similar!! The mainland & island subspecies may have greater genetic similarity amongst themselves... but "similar" is not "same". IMO it'll be a prudent compromise if they group all the tiger (& lion) subspecies into two clades, Mainland-Sundaland for tigers & Northern-Southern for lions.
Size of the Bengal tigers.
sanjay Rishi Modern weights and measurements on wild tigers in post #6 A friend of mine said that he is leading tiger tracker in Ranthambore. However, his answer was that Ustad was never measured. He also think Ustad was not Ranthambore's biggest tiger from his opinion. Wikipedia seems to be wrong. He said that journalists ask questions, then officials just answer. So we don't know what is actual measurements of Ustad. Don't trust too much information from the newspaper. He thinks tigers in central India like Raiyakasa, Dadiyal, Chota Munna, Jai, Umarpani, Bamera son are bigger than tigers in western India (Ranthambore) like Fateh and Kumbha. When I spoke to other photographers, they said they didn't really seen any size difference. We will never know unless someone measured them besides tigers in Sundarbans are definitely the smallest. Is it because of arid area, semi-desert habitat, genetic bottleneck, and less numbers of large prey animals such as Gaur, water buffalo, ... and other large animals? Large herbivores like sambar deer and nilgai are still exist in Ranthambore as well. Male tigers in Ranthambore definitely seems to be smaller heavy body and built compare to tigers from northern and central India. My other friend thinks northern Bengal tigers seem to be heavier since they have thicker coat than other parts of India. My belief is that Bengal tigers from northern and central India are all similar in size beside minor difference by individual. Also, there are just more numbers of heavier and bigger tigers in northern India, especially in Assam and Terai. However, it depends by individual. Western and southern India seems to be next, but I am sure there was big tigers that can match size with very large tigers in Terai and Assam in these areas. (06-24-2019, 05:22 AM)Rishi Wrote: Absolutely! Even if they're considered similar enough to be a single subspecies, Siberian & Caspian tigers lived far enough as well as segregated enough from each other to have significant genetic differences. I absolutely agree with your post. About Korean tigers, I read in news long time ago in Korean research team saying that 2 or 3 sequences were different from Siberian tigers in Russian Far East due to adapting in the Korean Peninsula. That's why Korean tiger had unique morphology compared to other Siberian tigers. I tried to search that journal, but I can not find it. It is the same for other tiger subspecies. It isn't just the tiger. Each tigers, leopards, snow leopards, cheetah, clouded leopard, and even other large mammals in Asia evolved unique adaptation, lifestyle, and morphology from habitats that they are living in. I do not want anyone to ruin that natural evolutionary process. We human already know that mother nature of Earth is far greater than us. No matter what, nature wins. It's been proven all the time from geology, physics, and biology as well. Invasive species is the answer of this. Nature has exact order to follow. Human shouldn't ruin it like 2 tiger subspecies. If you look current situation of the Aral sea, we've already learnt a lot of things that interference by humans will always cause disasters. (06-24-2019, 10:02 AM)Greatearth Wrote:(06-24-2019, 05:22 AM)Rishi Wrote: Absolutely! Even if they're considered similar enough to be a single subspecies, Siberian & Caspian tigers lived far enough as well as segregated enough from each other to have significant genetic differences. Firstly, take this into consideration, the reed region of the Panj River on the border of Afghanistan and Tajikistan in Central Asia, where the first tiger was apparently from (http://kavehfarrokh.com/iran-and-central...the-1930s/), is far away from and environmentally different to the hills or mountains of northern Iran in Southwest Asia, where the second tiger was from (http://www.tigers.ca/Foundation%20overview/caspian2.htm), yet nobody questions the idea that they are both Caspian tigers, or members of the same subspecies, right? *This image is copyright of its original author *This image is copyright of its original author Map of distribution of tiger subspecies by Vratislav Mazák, page 3: https://web.archive.org/web/201203091255...1-0001.pdf *This image is copyright of its original author Map by Luo et al.: https://journals.plos.org/plosone/articl...ne.0004125 *This image is copyright of its original author And Luo et al. (https://journals.plos.org/plosone/articl...ne.0004125) used at least one Caspian tiger that was West Asian, a captive tiger in Moscow Zoo that came from Northern Iran in West Asia, and its mtDNA was closer to the mtDNA of Amur tigers than those of some Bengal tigers to others, so just as 'subspecies' is a man-made concept, with one definition being about 2 populations of the same species that are genetically and geographically distinct from each other (https://www.merriam-webster.com/dictionary/subspecies), which wouldn't have applied when Caspian and Siberian tigers were contiguous, or when both were present in the area of Lake Baikal (https://archive.org/stream/mammalsofsov2...rch/Baikal), the names "Caspian tiger" and "Siberian tiger" are man-made names for a race of tigers that are distinguishable from other tigers in that they inhabited temperate or fairly temperate areas, such as northern Iran, the area of Lake Baikal, and the Russian Far East, whereas other tigers, with the exception of the Himalayan Bengal tiger, inhabit hot or warm tropical areas, in the same way that "Bengal tiger" is a man-made name for a tiger that inhabits India or South Asia, whether or not South Asian tigers are closely related in the same way as Korean, Manchurian, Russian, Central Asian and West Asian tigers are. If the great distance between the Amur tigers in Northeast Asia (Korea, Manchuria (Northeast China) and the Russian Far East) and the Caspian tigers in eastern Central Asia is enough to treat them as different subspecies, then why should the latter be treated as the same subspecies as the tigers in Southwest Asia (including Georgia and Iran), such as this Georgian or Iranian tiger (http://kavehfarrokh.com/heritage/the-las...n-georgia/)? *This image is copyright of its original author Luo et al.: https://journals.plos.org/plosone/articl...ne.0004125 "Tigers as a species historically ranged across Eurasia from the Sunda Islands, west through the Indian subcontinent to the Indus river and north along the Pacific seaboard to 60° NL and a wide swath of central Asia from the Russian Far East to eastern Turkey [1], [2]. This wide distribution was primarily influenced by environmental changes associated with Pleistocene glaciation events [3]. Commonly known as the Caspian tiger on the basis of its type locality (N. Persia), the historic range of Panthera tigris virgata also included Trans-Caucasia and Eastern Anatolia, with the greatest population densities in the riverine tugai forest systems of Central Asia [1], [2], [4]. During the Middle Ages Caspian tigers were resident across the steppes of Ukraine and southern Russia [4]. Between 1920 and 1970, tiger populations throughout Central Asia declined and disappeared for reasons common to tigers elsewhere: hunting, conversion of their limited habitat to cultivation with a concomitant decline in prey, and conflict with livestock [1], [4]–[6]. The Caspian tiger became extinct in February of 1970 when the last survivor was shot in Hakkari province, Turkey [1], [7]. In the era before molecular taxonomy tiger subspecies definitions were based on classical criteria: geographical origin, gross size and pelage variation (hair length, color, stripe number and patterning) (Figure 1) [3], [6], [8], [9]. Subspecies so described were often spurious as they were sometimes based on a single, possibly aberrant, individual, or from the unknowing sampling of clinal variation [3]. Such methods led to a lack of consensus, repeated taxonomic revision, and debate [10]. Though debate continues, eight tiger subspecies (three of which are extinct) are widely recognized based on these criteria [1], [2], [6]. However the phylogeny of the five extant recognized tiger taxa (P. t. tigris, P. t. altaica, P. t. amoyensis, P. t. sumatrae, P. t. corbetti) was revisited recently using mitochondrial molecular genetics by Luo et al. [11] who affirmed the validity of subspecies ranking for these groups. Additionally, these authors identified an equivalent sub-specific taxon unique to the Malay peninsula south of the Isthmus of Kra, formerly classified within P. t. corbetti but now designated as the Malay tiger, P. t. jacksoni. Panthera tigris virgata (Illiger, 1815) was the second tiger taxon described following the nominate Panthera tigris tigris (Linnaeus, 1758). However, because no holotype specimen of P. t. virgata exists, the relative scarcity of specimens, and the unreliability of morphological subspecies-diagnostic characters, the taxonomic validity of P. t. virgata has been questioned, its phylogenetic placement relative to other tigers is a matter of speculation, and its biogeographic origin unclear [1], [3], [4], [6]. Here, using well provenanced museum samples and ancient DNA techniques, we explore and interpret the phylogeographic natural history of the Caspian tiger, P. t. virgata in the genetic context of the living tiger subspecies, and explore possible routes taken during tiger colonization of Central Asia. Twenty (of 23) Caspian tiger museum samples (Table S1) were successfully sequenced for at least one segment of five mitochondrial genes – ND5, ND6, CytB, ND2, and COI (1257 bp), amplified as eight short amplicons to facilitate PCR of ancient material (see Methods). The amplification targets include 21 single nucleotide polymorphisms (SNPs), of which 14 are diagnostic (fixed differences) for subspecies affiliation in tigers [11], and include four of the four sites diagnostic for P. t. altaica, five of the seven for P. t. amoyensis, one of the three for P. t. corbetti, two of the three for P. t. tigris and both sites diagnostic for P. t. sumatrae. There are no diagnostic sites for P. t. jacksoni though we survey three signature alleles found uniquely in P.t. jacksoni. Seventeen of twenty P. t. virgata individuals carried a single distinctive mitochondrial haplotype, while three P. t. virgata tigers (Ptv-17, 22, 23) carried autoapomorphic variants (Table 1; Table S2). The amount of mtDNA variability observed in P. t. virgata (4 haplotypes/20 individuals), like P. t. altaica (1 haplotype/32 individuals), is low relative to other tiger subspecies P.t. tigris, (8 haplotypes/19 individuals); P. t. sumatrae, (10 haplotypes/31 individuals); P. t. jacksoni, (5 haplotypes/28 individuals); P. t. corbetti (5 haplotypes/33 individuals) [11]–[13] (Figure 2). Except for Ptv-5, housed in the Moscow Zoo but taken in the wild in Northern Iran, all Caspian tiger specimens are from individuals taken directly from the wild. Because these samples were collected between 1877 and 1951 (i.e., covering ca. 15 tiger generations) from wild tigers in China, Kazakhstan, Afghanistan, and Uzbekistan (see Table S1) it is unlikely they represent the sampling of a single extended family. Moreover, since sample collection took place over the broad geographic range of the subspecies when Central Asian tiger populations were still large, albeit declining, the low endemic mtDNA diversity (relative to other subspecies) indicates that low variability was a natural genetic feature of the 19th century Caspian tiger population and not an anthropogenic effect. To place more accurately the Caspian tiger relative to living tiger subspecies we re-assessed the phylogenetic relationships of tiger subspecies using a previously published dataset [11], but here rooted using clouded leopard (Neofelis nebulosa) [14], leopard (Panthera pardus) [15] and snow leopard (Panthera uncia) [16], with the inclusion of Ptv-2, the Caspian tiger for which the longest combined sequence was available (1.26 kb) (see Methods). The rooting imparted evolutionary polarity to the tiger family tree and showed P. t. amoyensis to be basal and P. t. altaica to be a sister group to P. t. corbetti, while the Caspian tiger haplotype was one step away from that of P. t. altaica (Figure 2). The phylogenetic placement and remarkable similarity observed between P. t. altaica and P. t. virgata indicate that the Amur tiger population is the genetically closest living relative of the extinct Caspian tiger, and strongly implies a very recent common ancestry for the two groups. Russian records from the 19th and early 20th centuries indicate that tigers were sporadically present throughout the region between the core distribution of Caspian and Amur tigers (see Figure 1) and were only hunted out in the modern era [4]. Thus, the actions of industrial-age humans may have been the critical factor in the reciprocal isolation of Caspian and Amur tigers from what was likely a single contiguous population. The origin of the Amur tiger population is estimated at less than 10,000 years ago by molecular genetic analysis: using a rate of mitochondrial evolution calibrated on the tiger-leopard split (estimated at 2 million ya.), Luo et al. [11] inferred that the P. t. altaica population, which showed no mtDNA variation, underwent a genetic reduction less than 20,000 ya, that being the time required for a single mutation to appear. The authors then refined their age estimate of the P. t. altaica subspecies further to around 10,000 ya. using a standard curve of the relationship of microsatellite allele variance in average repeat size to elapsed time [11]. This estimate is supported by biogeographic reconstructions of tiger range covering the last 20,000 years [3]. Furthermore, paleontological evidence suggests that morphologically modern tigers occurred first around two million years ago in eastern China (in the historic range of modern P. t. amoyensis) [8], suggesting that tigers in China may have comprised a stem group that gave rise to modern subspecies. Tigers only recently expanded to the Indian sub-continent (6–12 kya), the Russian Far East (late Pleistocene/Holocene) and Central Asia (Holocene) [1], [3], [4], [10], perhaps impelled by climatic and ecological changes associated with the end of the last glacial period [3]. Therefore, if 19th century Caspian and Amur tigers comprised a single population (as supported by these genetic data), then Caspian tiger diversity (or lack thereof) would likewise date to less than 10,000 years."
In latest discussion about subspecies it is good to remember, that legit biologists, zoologists and scientists are having there disagreements. So it would be surprising, if there wouldn´t be disagreements among people who are very interested about wildlife. That´s why it is good to remember, that if professionals can´t find a clear agreement, it can´t be expected here. So writing something like "that logic is absolutely wrong" is very strong statement and rises up question, that with what competence such statement is made? Especially when situation is like that.
Would it be better to say something like, "I can´t agree with your logic, because....". When looking at subspecies, one issue are possible genetic differences as far as I know. Then we can have some visible differences in size, looks etc. for some reason making population from some area to be easy to identify when comparing to population in some other area. Then we can have maybe some other reasons... There can be then agreements or disagreements, that how big genetic differences can be considered so relevant, that some populations should be considered different subspecies. Something like that can be seen in latest debate between tiger specialists, which have leaded to current situation where Cat Specialist Group suggested two subspecies, but which in reality haven´t lead to any changes in for instance Amur tiger conservation. And as far as I know and believe, also no changes what comes to conservation of Bengal tigers. This issue is quite complex, so when making postings and statements, I think that most would appreciate when text is wrote carefully and making clear points of view(s) and good reasoning easy to read. But everyone have to understand, that now we aren´t discussing about weights or heights, when talking about subspecies. There is no clear measurement to use in judging, who is right or wrong. Keeping that in mind and keeping calm is best way to discuss about a bit unclear things. I can understand point of view of @ (06-24-2019, 04:53 PM)Shadow Wrote: In latest discussion about subspecies it is good to remember, that legit biologists, zoologists and scientists are having there disagreements. So it would be surprising, if there wouldn´t be disagreements among people who are very interested about wildlife. That´s why it is good to remember, that if professionals can´t find a clear agreement, it can´t be expected here. So writing something like "that logic is absolutely wrong" is very strong statement and rises up question, that with what competence such statement is made? Especially when situation is like that. Yes, and @ Pages 130–141: *This image is copyright of its original author *This image is copyright of its original author ... *This image is copyright of its original author
MAN-EATING TIGERS IN NEPAL - I
Nepal today has 235 tigers, about twice as much as a decade ago. The effort to protect wild country and wild animals paid, that is. Great news. Most unfortunately, there is a flipside. Most tiger reserves in northern India and southern Nepal are situated in a densely populated region. This means they, more often than not, are surrounded by villages populated by poor people struggling to make a living. Not a few of them use these reserves to feed their cattle. Very often, they just don't have another option. The most likely result of more villagers in tiger reserves and more tigers in these reserves is more encounters. Some of these have a tragic outcome. Man-killers often get the benefit of the doubt but when they develop into confirmed man-eaters, authorities have no option but to act. The aim is to capture the tiger alive. Not easy by any means, as tigers are elusive animals. Every now and then, an attempt to sedate a man-eating tiger develops into a chaotic affair with a deadly outcome. LINKS a - A man-eater in the Kathmandu Zoo (article and video) If you click on the first picture in the article, a video (01:57) will start. In the video, 'host' Casey Anderson sits himself in front of the cage with his back to the tiger. His first aim is to provoke the tiger, a confirmed man-eater. His second aim is to 'prove' an attack can be prevented if it's noticed in time, provided the intended victim is able to connect to the tiger by looking into his eyes for a prolonged period of time. The attempt to provoke the tiger succeeded in that the tiger approached Anderson after some time. It failed in that the tiger growled before he approached. This means he didn't see him as a snack, but as a challenger or, more likely, as a nuisance. Not the response Anderson anticipated. The stare also failed. A result of a poor preparation, so it seems. Any trainer could have told him tigers and lions respond in a different way to a stare. Lions, more often than not, react, but most tigers do not. They're not interested in staredowns, but in something else. Like a meeting without bars. In the end, as the tiger in the video underlined, it is about the teeth. All in all, one could conclude the tiger acted in a somewhat surprising, but civilized way, whereas Anderson, especially during the stare, lost a bit of face. Final score: Anderson 0 - tiger 4. The article about tigers and humans in India and Nepal isn't too bad. It has a few links to articles published in the New York Times: https://www.monstersandcritics.com/smallscreen/casey-anderson-faces-a-man-eating-tiger-in-monster-encounters-exclusive-interview-and-preview/ b - The attempt to capture a man-killer in Nepal in 2018 The article in 'The Himalayan Times' (31-08-2018) is a bit short, but informative. It also has a photograph. The story is short. After he had killed a man in Royal Chitwan, the tiger was located, cornered, sedated and moved to a zoo. Although things went according to plan, it took a week to get it done (...). The tiger was an adult male wounded in a fight: https://thehimalayantimes.com/nepal/man-eater-tiger-captured-after-week-long-operation-in-chitwan/ |
| Users browsing this thread: |
| 30 Guest(s) |