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)
|
01 - CURRENT STATUS (2015)
At the turn of the last century, there could have been about 100.000 wild tigers in Asia. Today, " ... fewer than 4000 inhabit the forests of Asia - a historically low number. These tigers occupy only 7% of their former estimated distribution range ... and 70% of them ... occupy only 0,5% of their historical range ... " ('Planning Tiger Recovery: Understanding Intraspecific Variation for Effective Conservation', Wilting et al., 2015). As many live in isolated small patches not connected to others, it has to be expected the lack of new genes will have significant consequences. Most wild tigers are doomed, that is. Experts think only tigers living in south-west India, the Terai and Primorye could stand a chance in the long run, which would be some decades. Recent reports of TRAFFIC and other organisations, however, show tigers are poached in these regions as well. Most poached tigers pop up in small parts in some form somewhere in Asia. Tiger poaching is an interesting business on account of the very limited number of wild animals. The trade in wild animals all over the world is big business. Billions of dollars every year also means poachers are well armed and dangerous. If what we see today is typical for the future, a policy like the one adopted in Kazirangha might be the only option. This thread is dedicated to tigers. Anyone with good information is invited to share it here.
02 - EVOLUTION
Tigers very probably evolved in the south-eastern part of China and the north-eastern part of Indochina roundabout 2 million years ago. Many researchers think they spread from there in different waves. The first wave ended in Java, whereas the last was directed at the region between and just south of the Black and the Caspian Seas. The last wave probably ended 10.000-12.000 years ago and originated in northern China. As researchers found no significant differences between Panthera tigris virgata (the Caspian tiger) and Panthera tigris altaica (the Amur tiger), we have to assume they probably are, or more accurately were, one and the same. Another quite recent wave south of the Himalayas ended in the extreme north-west of India. Kashmir and the Indus River could have been the most northerly and westerly limits. Tigers in central and southern parts of India seem to be somewhat different from those in the north of India, suggesting they could have entered India before the new wave entered north India. This would, at least partly, explain the differences seen between both populations. The story on Sumatran tigers is quite complicated. It is very likely Sumatra was populated by tigers from the first wave and it is also likely they completely vanished as a result of the Toba eruption some 75.000-80.000 years ago. After the eruption, Sumatra was re-populated from both Java and Malaysia. This would explain the remarkable variation seen in Sumatran tigers. The differences between them and other subspecies is of such dimensions that researchers proposed to change Panthera tigris sumatrae to Panthera sumatrae. A prototype of the true tiger, that is. I have some doubts, but there is no question all island tigers are quite different from mainland tigers in many respects. Recent research suggests Bali tigers were more related to Java tigers than to any other regional type. The skulls I saw confirm they probably were closely related. Today, Panthera tigris balica is seen as a subspecies of the Java tiger. As the Java tiger changed from Panthera tigris sondaica to Panthera sondaica, the correct name for the Bali tiger is Panthera sondaica balica. The Bali tiger became extinct in the late fifties of the last century. In most models used to predict the presence of tigers, it was assumed tigers, as a rule, would avoid elevated, arid and open regions. J.F. Brandt (1856), after reading everything written on tigers in his day, however concluded tigers were present and even quite numerous in northern and eastern parts of Tibet as well as in barren and elevated regions of Central-China. A recent expedition confirmed tigers live and breed in suited regions of Bhutan at 10.000-12.000 feet. Tigers were also reported in eastern parts of Afghanistan only recently. This means assumptions about the most likely route tiger followed when they spread towards the Caspian could have to be revised. Afghanistan, tigerwise, is somewhat unclear. There are too many recent reports on tigers to be dismissed out of hand, but it also is a fact not one expedition produced strong evidence of tigers living in Afghanistan today. Many assume Javan tigers became extinct in the seventies or eighties of the last century, but there are persistent rumours about big cats in isolated parts of south-central and eastern Java. Although no evidence was produced so far, leopards were eliminated as candidates. Unclear. In the last decade, many interesting articles on the evolution of tigers have been published. These strongly suggest the classification proposed by R.I. Pocock in his article on tigers of 1929 (first published in the Journal of the Bombay Natural History Society) can no longer be used as a 'working-hypothesis'. 
I am also finding it difficult to post scans or pictures here.
Nice info peter. 
@Pckts
I just made a tutorial to insert image from other source on internet. Here is the link http://wildfact.com/forum/topic-how-to-i...this-forum Please read it carefully. 
Hey guys, for those which want to read the book of Gerald Wood from first and, here is the link: openlibrary.org/works/OL14928697W/Animal_facts_and_feats
Choose the section "Borrow" and "eBook" However, you most take in count this: 1. This is like a physical library, if you borrow it (the ebook), you most return it, in order than other people can read it too. 2. If the book is already borrow, you most wait until the book is again available. 3. Use it only the necesary time. If you are not going to read it, return it for the use of other persons. 4. You can't download the book, this is not a PDF. In order to get the pages, you most save the webpage in and from new created carpet, you retrieve the selected images (you can save only two at the time). 5. If you can't do this, just tell what page (or pages) do you need and I will retrieve it for you. You most create an account first, but don't worry, it is completely free. Enjoy the reading. The tiger, evolution and taxonomy In all these years that I have studied tigers, I have managed to reconstruct the entire evolutionary history of the tiger. This is a large summary of all the data that I have compiled and posted in several topics, especially those about the Ngandong tigers. Also I present a good recount of the taxonomical studies on the tigers, providing the three taxonomical groups proposed for the modern tigers. It is a long post, read it, save it and discuss it. Tiger evolution: Tigers are part of the Panthera genus, which evolved about 4 million years ago, represented by Panthera blytheae like the first branch of this new form of predator. After this species, other great cats evolved, among them Panthera palaeosinensis and Panthera zdanskyi (The Longdang “tiger”), and with them the snow leopard (Panthera (Uncia) uncia) and the tiger (Panthera tigris); only the last ones exist in modern times. Jaguars-leopards-lions evolved more lately than these cats, although a large lion-leopard cat has been identified in the Laetoli area and dated about 3.5 million years ago. The first fossils identified as “tigers” are found in central China, in areas like Honan, Yunnan, Hubei and Choukoutien. However these fossils are too fragmentary and need more studies in order to clarify they taxonomic status. The first “true” tiger fossils are found in Java, in the deposits of Ci Saat and Trinil, about 1.6 million years ago. This first tiger form is known as the Trinil tiger (Panthera tigris trinilensis). It was a primitive tiger with relative larger carnassial and was no larger than modern Javanese tigers. At the early Pleistocene, the Sunda shelf (Sumatra, Java, Bali, Borneo) was connected to mainland by a land bridge, which was used by the Trinil tiger to enter into the Asian continent and replaced the primitive Chinese form. This was the first wave of the tiger evolution. In the middle Pleistocene, the new tiger at mainland evolved in a new form known as the Wanhsien tiger (Panthera tigris acutidens). This tiger subspecies lived up to the late Pleistocene and varied in size from the small Sunda tigers (earlier forms) to the larger Amur-Bengal tigers (late forms). Meanwhile, the Sunda population evolved in a new form named Panthera tigris oxygnatha, that was not different from the Trinil form in size, but had a different masticatory system with more wide carnassial teeth (no long bones have been found). Meanwhile, the Wanhsien tigers expanded its territory to the north of Eurasia, reaching the area known as Beringia and up to Alaska. This other form of tiger was of the same size than modern Amur-Bengal tigers and coexisted with the cave lions (Panthera spelaea spelaea). However, as tigers are tied to the forest areas, they were unable to adapt themselves to the great steeps of Beringia and this population doesn’t prospered like the southern forms. By the late Pleistocene about 100,000 years ago, the land bridge still connected the Sunda with the mainland, and the new large Wanhsien tigers began to expand its habitat and provoked a new wave that invaded the Sunda and replaced the original Sunda tigers. This new situation caused a new change in the Sunda ecology and with the large prey base at that moment, comparable with that of the richest areas of India, promoted the evolution of a new form known as the Ngandong tiger (Panthera tigris soloensis). This new subspecies was the largest tiger known in the fossil record and probably the largest Panthera member ever known. This giant had the same proportions than the large mainland tigers but its skull presented characteristics that were new in fossil records (elongated carnassials, smaller sagittal crest, and narrowed occiput) and that was the first time than the characteristics of the modern Java-Bali tigers are found in fossil records. Based on this, it is not clear if the mainland tigers completely replaced the old Sunda form or only mixed with it. At about 70-80 thousand years ago, a cataclysmic event known as the Toba eruption destroyed all the north and central part of Sumatra and affected the climate of all Asia (probably the entire world), creating a series of extinctions and genetic bottlenecks among the surviving species. Tigers were no different as the species was nearly extinct after this event. However, the great cat is a very resilient species and recovered very well after this natural tragedy. A small population of Sunda tigers that lived in the eastern part of the Sunda shelf recovered and began to spread to the west area; these tigers were the first modern Java-Bali tigers, that retained the cranial characteristics of the Ngandong tiger but that began to suffer the island dwarfism. Meanwhile, the entire mainland tiger population was reduced to a small patch in the south China-northern Indochina region. According with genetic studies, this small population gives origin to the entire modern mainland tiger population, with the South China tiger (Panthera tigris amoyensis) been the oldest and more primitive form. After this, tigers began to expand its territory to the north of China and to the Indochina region. Tigers invaded the center of Asia up to the Caspian region through the famous Silk Road and created the western population known as the Caspian tiger. However, this same population began to expand its territory following the rivers of north central Asia and reached the Baikal Lake and with time, the entire Russian Far East. This large tiger population remained together up to 200 years, when the modern human activities separate them and the population of the Amur area was isolated from that of East Asia, only the Amur population survived to the 20 century. The area of India was too dry through all this time, but about 12,000 years ago, at the end of the last ice age and the beginning of the Holocene, the tiger first entered to the Indian subcontinent and rapidly conquer the entire region, despite the presence of the Asian lion (Panthera leo persica) and the human (Homo sapiens). In fact, in India, the tiger evolved its most magnificent form, adapted from the northern areas of the Himalayas to the swamps of Sundarbans and the large forest of the Karnataka region. The Indian tigers developed a series of adaptations, that for the old hunters and naturalists represented different subspecies, however these where only clinal adaptations and new genetic studies shows that all the Indian-Nepal-Bhutan-Sundarbans tigers are of the same subspecies (Panthera tigris tigris). Finally, what happen with the empty space between mainland and the Sunda shelf? Whell, in the time while the land bridge still existed (20-50,000 years ago), the mainland tigers began to travel to the south and the Sunda tigers to the northwest. Eventually, they join in the area that will be known as Sumatra. Here, something particular happened, the two subspecies mixed and they give origin to the modern Sumatran tiger. This new tiger present characteristics of both varieties but also evolved its own characteristics; recent craniological and genetic studies show that this is in fact, a different species, or at least, at the brink of been one. At 10,000 years ago, already in the modern age, the tigers were already spread in the known places, from the Russian far east to the Malayan peninsula, from the Caspian see to the islands of Amoy in China, and from the Pakistani valley of the Indus through the south of eastern Asia and the Sunda islands of Sumatra, Java, Bali and Borneo (this last population get extinct before the history time). Evolution in few words: The fossil record show that the first "true" tiger lived in Java during the early-middle Pleistocene and it was the Panthera tigris trinilensis. However, this relative small tiger invaded mainland, replacing the primitive China tigers and gives origin to the large Wanhsien tiger (Panthera tigris acutidens). Latter by the upper Pleistocene, a second wave from China invaded the Sonda shelf (Sumatra, Java, Bali and Borneo, together), replacing the local tiger population (which in that time, was the Panthera tigris oxignata). So, by the final of the Pleistocene, there were two large tiger species, the large Wanhsien tiger (Panthera tigris acutidens) in mainland (China to Beringia) and the larger Ngandong tiger (Panthera tigris soloensis) from the Sonda shelf (Groves, 1992; Hertler & Volmer, 2007). By end of the Pleistocene (75,000 - 108,000 ago), the great Toba eruption destroyed almost all the ecosystem of southern Asia and its species, forming several genetic bottle necks, and according with Luo et al. (2004), the last remnant tiger population that inhabit the north of Indochina, gives origin to all the modern mainland tigers (the South China-North Indochina tiger Panthera tigris amoyensis was the first of these new mainland tigers (Luo et al., 2004; Driscoll et al., 2009)). In other words, the large Wanhsien tiger is the direct ancestor of the entire modern mainland "Panthera tigris" (tigris, altaica, virgata, corbetti, amoyensis and jacksoni). The island tigers (Java and Bali) are the last remnant of the giant Ngandong tiger, which already showed the particularly narrow occipital with is characteristic of the Javanese tiger. This suffer from Island dwarfism and by the early Holocene, they were already of the size of an average South China tiger. The Sumatran tiger seems to be a hybrid between the mainland population and the Javanese tigers that repopulated the area. The genetic studies of Cracraft et al. (1998) and Luo et al. (2004), together with the morphological analysis of Mazák & Groves (2006) and Mazák (2010) support the "species" status of Sumatran tigers (Panthera sumatrae). Interesting as it is, the evolutionary history of the tiger is incredible and based in several re-colonization, not just one simple migration from north to south like is suggested by early studies (Mazák, 1981; Heptner & Sludskii, 1992). Old taxonomy like that of Pocock is now outdated and most be discarded, especially by the fact that he based his statements in very few specimens. The Holocene tiger and its taxonomy: The classification of Dr Vratislav Mazák (1981; 1983) is the most widespread among scientific documents and he stated that there is one tiger species and eight subspecies separated by its body size and pelage (although based in very few specimens). Latter, Dr Kitchener (1999), based in a craniological and pelage study, showed that the “differences” among the putative tiger subspecies are only clinal and that the sample used for the “subspecies” classification is ridiculously small and reflects no real variation. He stated that there are no significant differences to show that there are subspecies at all, but based in morphological evidence (few specimens again), stated that there are only three subspecies (1. Mainland, 2. Island and 3. The Caspian). On the genetic side, Cracraft et al. (1998) proposed that there is not enough difference subspecies between the mainland tigers, but that the Sumatran tigers are different enough to separate them like a different species (not even subspecies). Luo et al. (2004; 2010) presented genetic evidence to show that there are in fact, enough genetic evidence to sustain the differentiation of five modern tiger subspecies and even proposed a sixth one (Malayan-jacksoni). Latter, Mazák & Groves (2006), using a morphometric study, stated that there are enough differentiation between mainland tigers (Corbetti only) and the Sonda tigers, to classified them like a different species, but disproved the claim of Luo et al. (2004) about the separation of the Malayan tigers as a subspecies, because they don’t found any difference between them and those from Indochina. The final study of J. H. Mazák (2010) on the Craniometrical variation of tigers show, again, that there is great differences between the mainland group and the island group and that the Sumatran tigers were probably a hybrid between the two populations. About the Caspian tigers, Driscoll et al. (2009) found that the Caspian tiger population was genetically undistinguishable from the Amur tigers and proposed to join the two groups into one subspecies (Virgata), discarding the statement of Kitchener (1999) that this group was a different subspecies. Besides, J. H. Mazák (2010) also found that the Caspian tigers had many morphological characteristics in common with all the other mainland tigers (disproving Kitchener (1999) again) and that the most different of all the mainland specimens were those from Amur, which were practically the most earlier in evolve. Finally, Kitchener & Yamaguchi (2010) repeated the same claim from 1999, adding several complaints about all the previous studies, for example: 1. The genetic study of Luo et al. (2004) had not enough specimens and that they can’t explain why Bengal tigers are far away than Sumatran tigers in the genetic graphics. 2. The morphometric study of Mazák & Groves (2006) doesn’t use other mainland skulls, which according with Kitchener (1999) also present the narrow occiput of the Javanese tigers (although he used fewer specimens than those used by Mazák and Groves). 3. The differentiation of the Malayan tigers is invalid as they don’t present a holotype and the genetic evidence is not enough to establish it as a species. However, they slightly mention the fact that Kitchener (1999) was wrong about the Caspian tigers and that his biogeographic analysis (Kitchener & Dungmore, 2000; repeated in 2010) failed in predict the populations of tigers in that area. Here is what I can quote from memory right now and based in all this, I can state that there are several forms to assimilate all this information. I prepared three cases, which can be used for tiger specification: Case 1 - The most simply form: Two species: * Mainland tiger: (Panthera tigris) - no subspecies. * Island tiger: (Panthera sondaica) - no subespecies. Case 2 - Based in morphometric and genetic analysis Three species with subspecies (or two and one hybrid): * Mainland tiger: (Panthera tigris): - Bengal tiger (P. t. tigris). - Caspian-Amur tiger (P. t. virgata). - South China tiger (P. t. amoyensis). - Indochina tiger (P. t. corbetti) - including jacksoni. * Island tigers: (Panthera sondaica): - Javan tiger (Panthera sondaica sondaica). - Bali tiger (Panthera sodaica balica). * Sumatran tiger: (Panthera sumatrae (tigris x sondaica)). Case 3 - Proposed by Kitchener, with modifications: One species (Panthera tigris) with two subspecies and one hybrid: * Mainland tiger (Panthera tigris tigris) - only clinal variations. * Island tiger (Panthera tigris sondaica). * Sumatran tiger (Panthera tigris sumatrae (tigris x sondaica)).
Great summary Guate. Many thanks. Any chance you are able to construct an image with a timeline, thus allowing for an overview at a glance?
Oh yes, of course. It will take time, but I want to use good images in each branch. No Uchitel images or anything like that. I want my images here.
Hello everyone
I am planning on creating a similar table to Guates like the average body mass of east African lions Guate did sometime ago. This time it will be with all the availabile records I can find on tigers. It will be done on a similar manner as Guate did here... It will take all the individual records and put them into a large sample http://animalbattle.yuku.com/reply/639/E...#reply-639 Here is the sample of all the other figures in literature I can find. All are males and measured (in cm) between pegs, but the important figure here is the weight: Tiger No. Total length Weight in kg (and lb). Reference 1 , 292 198.2 (437) ,Baker, 1891 2 , – 236.2 (520.8) ,Brown, 1893 3 , - 203 (448) ,Lockyer, 1876 4, – 158.5 (349.5) ,Sanderson, 1879 5, – 161 (355) ,Inverarity, 1888 6, 283 172.4 (380) ,Lydekker et al., 1897 7, 267 164 (362) ,Lydekker et al., 1897 8, – 267.6 (590) ,Singh, 1959 9 , 323 222.7 (491) ,Ward, 1907 10 , 306 252.7 (557) ,Ward, 1921 11 , – 275.8 (608) ,Pocock, 1939 12, – 272 (600) ,Singh, 1970 13, – 250 (551) ,Chundawatt, pers. Comm. 14, – 240 (529) ,Chundawatt, 2004 15, – 220 (485) ,Sariska NP, web page 16, 297 188.7 (416) ,Burton, 1915 17, 292 256.3 (565) ,Berg, 1943 18 , 295 227 (500) ,*Burton, 1936 19, – 156 (344) ,Marshall, 1937 20, – 149.7 (330) ,Marshall, 1937 21, 285 213.2 (470) ,Stewart, 1927 22, - 227 (500) , *Alabama Conservation, 1944 23, - 292 (645) , Ward 1922 24, - 217 (478) , Ford News 1923 25, - 225 (496) , Quarterly 1956 26, - 224 (494) , Quarterly 1956 27, - 186.4 (411) , Quarterly 1956 28, - 159 (350) , Wroughton JBNHS (Vol. 22, pp. 29-66) 29, - 149.2 (329) , Buckland 1885 30, - 205 (452) , Buckland 1885 31, - 247.2 (545) , Ward JBNHS (Vol. 31, pp. 1-2) 32, - 217.7 (480) , Morris 1923 33, 292 181 (400) , Baker 1891 Average 212.3 kg (468 lb), n=33 *Exceeded scale limit NOTE: This table aims not to include any tigers from Sundurbans, due to possibility they are genetically separate subspecies. No weights above 300 kg included. I will change this table later. I will be adding to this soon
Many years ago, while trying to find Dunbar Brander's book on Indian wildlife ('Wild Animals of Central India'), I found a French translation (...) in a secondhand bookstore. I still have it.
Unfortunately, I never found Dunbar Brander's book in English. Later, on AVA, I saw a number of pages from the original. They were posted in a thread on the size of Indian tigers. I compared them to the same pages in the French translation and concluded the translation (in which feet and pounds were replaced by cm. and kg.) was not quite accurate. For this reason, I never quoted from the French translation. The cover of the French translation, however, was scanned because of the nice tiger. He probably was one of the tigers Dunbar Brander shot, but I'm not sure as there is no information on him in the text. Here's the cover of the French translation:  *This image is copyright of its original author
(04-07-2014, 02:02 AM)'Kingtheropod' Wrote: Hello everyoneKingT, the book of Gerad Wood (1978) will help you with the length of some of those males that you used:  *This image is copyright of its original author I will help you with that, but for now, I am finishing the table about the size of Indian lions. (04-07-2014, 04:20 AM)'peter' Wrote: Many years ago, while trying to find Dunbar Brander's book on Indian wildlife ('Wild Animals of Central India'), I found a French translation (...) in a secondhand bookstore. I bought it and still have it.That is a massive tiger. Could be this the famous giant of 221 cm head-body from Brander? The tail of the tiger in the picture is very short, just like the huge male. I will love to have a picture of him. [img]images/smilies/tongue.gif[/img]
In those days, photography was very different from now. The equipment was heavy and not easy to transport. I recently read a book of C.H. Stockley ('Stalking in the Himalayas and Northern India' - Indian reprint).
The book was first published in 1936. Stockley wrote it wasn't easy to move his equipment as a result of the tough conditions he faced. His book has many photographs of wild animals, of which quite many were, to put it mildly, somewhat blurred. The main reason was it was too difficult to get the equipment installed at the right time and place. My guess is Dunbar Brander didn't carry equipment when he was travelling. If a tiger was photographed, he probably was taken back to camp to be weighed and photographed. As the 9.11 tiger wasn't weighed, my guess is he wasn't moved to camp. This means chances are wasn't photographed. My guess, therefore, is this was another tiger. I agree it is a muscular animal, but so were many in Central-India. Those with experience all agreed Central-Indian tigers were heavy, short-tailed and stocky as a rule. For some confirmation, go to the Journal of the Bombay Natural History Society. There are plenty of letters on average-sized and heavy Central-India tigers. Remember the table of Captain Hunt in the JBNHS? It had 6 big male tigers, of which the longest was 9.3 'between pegs' only.
Oh well, but I am sad. I would like to see him, in order to have the large tiger of Jankovskii and the Bachelor of Powargarh and make comparisons with the giant of Brander. [img]images/smilies/sad.gif[/img]
02 - EVOLUTION (continuation)
Palawan Guate's overview of the evolution of the tiger is the most extended and comprehensive overview I read. Although it probably explains the presence of tigers in Japan and Palawan (Philippines), one would like to read a bit more on the circumstances that resulted in the extinction of tigers on those islands. It is known that mammals living on islands adapt over time in getting smaller (as a general rule), but the causes of extinction are not well understood. Sumatra also is an island and still has tigers. Java and Bali, like Sumatra, would have had tigers today if it hadn't been for humans. But there are humans on Sumatra as well and Hokkaido and Palawan also had humans. Same for Borneo and, possibly, Shri Lanka (skulls and bone fragments of big cats were found on Shri Lanka in the recent past). My guess is more remains of big cats will be found on some islands in south-east Asia in the near future. There had to be other factors that resulted in the extinction of big cats on these islands, that is. Anyhow. This abstract of a study I, unfortunately, didn't read, proves tigers inhabited Palawan:  *This image is copyright of its original author
Palawan was in extreme northern part of the Sunda shelf. In this case, it is completely plausible that some tigers lived in that area, although with the rise of the sea level, the island was unsuitable for such a large cat, and taking in count the behavior of humans, is probably that the few tigers were hunted by the earlier humans.
About the Japanese tigers, it is possible that this was in fact, the lasts of the original tiger population that evolved in China, and that invaded Japan trough a land bridge in the Russian Far East. It have some morphological similarities with Panthera palaeosinensis. I am going to post the map of the possible land bridge latter. |
| Users browsing this thread: |
| 14 Guest(s) |