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)
|
 (10-01-2016, 10:52 PM)Pckts Wrote: "trivial" would be subjective though, right? Under the natural occurrence, all tiger subspecies that share the geographic proximity would have the genetic exchange at some point. Now the complete isolation between the tiger subspecies is in fact not under the normal circumstance, and were artificially made under the human interference. From a genetic standpoint, all diversification of the outer appearance is undoubtedly trivial. Look at the difference between the canine breeds, they all belong to one single subspecies, and the diversification of their outer appearance in fact even exceeds that of the modern humans. All modern tiger subspecies were in fact a re-combination of the ancient tiger subspecies that survived after the prehistoric catastrophe, so let them evolve under their own way. I am not advocating to mix them on purpose under the captivity, but no need to go under another extreme over the genetic purity. In my opinion, both to mix them on purpose or to isolate them on purpose are in fact human's "playing God behavior". I don't like the extreme on the two sides of the same coin.  (10-01-2016, 10:58 PM)GrizzlyClaws Wrote: @Apollo Sunda tiger is just a senior synonym for the Java tiger and Bali tiger. So sumatrans are hybrids of mainland and sunda tigers. Are sumatrans bigger than sunda tigers (since mainland tigers are bigger than sunda) ? What common traits sumatrans have from both the tiger groups ? Did sunda tigers migrated to mainland through sunda shelf bridge ? Do mainland tigers show any sunda genes ? 
They were not necessarily bigger than the pure Sunda tigers.
From a genetic standpoint, they discovered that the Sumatran tigers were hybrids, but from the morphological perspective, they were completely convergently leaning toward the Sunda tigers, since they live in the similar environment. If the migrating Sunda tigers mixed with the Mainland tigers in the Mainland Asia, then I am pretty sure their hybrid descendants would share more morphological traits with the pure Mainland tigers. The morphological traits are just a sign of adaption in the different respective environments. (10-01-2016, 11:52 PM)Pckts Wrote: I agree @GrizzlyClaws From the conspecific point of view, all different subspecies are essentially the same, since they all belong to the same species who don't share any incompatible genetic barrier. Their hybrid offspring can all be fertile and produce the healthy descendants, unlike the inter-specific hybrid such as the ligers. But of course, all the inner intra differences still exist among every single species, but these differences are relatively trivial, not at the conspecific level. Just look at the South China tigers, since their own gene pool is nearly gone and cannot restore their population anymore. So the only way to bring them back is to borrow from the gene pool of the other tiger subspecies. In my opinion, all Mainland tiger subspecies shouldn't be a bad choice, since they all shared the genetic exchange with the South China tigers in the past. 
Excellent work, Grizzly. As to the questions of Apollo on size:
1 - Skulls Skulls of Javan tigers are a bit longer than those of Sumatran tigers. In females the difference is very limited, but in males it's over 10 mm. The largest skull, however, was a Sumatran tiger skull. Skulls of male Sumatran tigers also show distinctly more variation in size. Although some skulls of male Sumatran tigers are almost similar to a typical skull of a male Javan tiger, skulls of Javan tigers are generally more vaulted. Furthermore, many have a quite concave mandibula. In Sumatran tiger skulls, mandibulas can be straight or even slightly convex. In Javan tiger skulls, the occiput is constricted. This is not seen in other subspecies. In some skulls of male Gir lions, however, the occiput also is a bit constricted. Although skulls of Javan tigers are different from skulls of other tiger subspecies, skulls of Indian tigers are quite close in many ways. In both subspecies, the skull quite often is rounded and vaulted. Skulls of tigresses are smaller all the way. Not seldom, the sagittal crest is hardly developed. Although there are distinct differences between skulls of different subspecies, they are not as pronounced as in skulls of male tigers. 2 - Length and weight I have some measurements of Sumatran tigers measured 'between pegs'. From memory, six Sumatran males averaged 236-237 cm. (about 7.9) in total length. Based on what I have, my guess is Javan males could have been a bit longer. How much longer is anybody's guess. I'm not sure, but my guess is Sumatran tigers showed more individual variation. Sumatran males (sample < 10) averaged 115-120 kg., but the range is impressive. Tiger 'Slamet', recently weighed, was just over 148 kg. (about 327 pounds), but a tiger shot on a plantation between 1930-1940 seemed heavier and I found more information about large male Sumatran tigers shot between 1900-1940. In general, Sumatran male tigers seem quite stocky and robust, more so than tigers in the southern part of Malaysia. Most photographs of Javan tigers I saw suggest they could have been a bit taller and longer, but not more robust. One male was 141 kg., but that's all we have so far. As to why Javan tigers were quite different from Sumatran tigers. One reason could be genetics. Another could be habitat. Sumatran tigers live in dense tropical forests, whereas Javan tigers lived in more open forests. A third reason could have been humans. In Java, they already were on their way out at the end of the 20th century. In Sumatra, the pressure was much less intense. 3 - Sumatran and Javan tiger compared - photographs a - Eastern Java, 1938 (Hoogerwerf):  *This image is copyright of its original author b - Western Java, female (1941):  *This image is copyright of its original author c - Central Java (not sure), male - first posted by Phatio:  *This image is copyright of its original author d - Sumatran tiger 'Slamet' (just over 148 kg.):  *This image is copyright of its original author e - Although well over 9 feet 'over curves', this male wasn't the longest. He could have been the heaviest, though. Shot on a plantation where he had killed and eaten a male sun bear some time before he was shot. Although loaded, it was a robust male tiger:  *This image is copyright of its original author f - Same hunter, different tiger (Lampung, 1941):  *This image is copyright of its original author g - Notorious man-eater. From memory, he had killed and eaten at least 69 people. One possible reason he hunted humans was a disability. The tiger was nicknamed 'De Kreupele' (kreupel refers to crippled). Although the angle definitely had an effect, the old man-eater had a large skull:  *This image is copyright of its original author h - Recent photograph:  *This image is copyright of its original author 4 - Tables I went over everything I have on Sumatran, Javan and Bali tigers (skulls, measurements and weights) some time ago. I didn't have the opportunity to do the tables, but I will as soon as I can. In the skull tables, I'll distinguish between young adults, mature animals and old tigers. The differences are remarkable.  (09-21-2016, 04:14 PM)peter Wrote: Good info and thanks, Diamir. Here's a few more questions. your questions answered 1) I could not find the other information (reliable information) about young Amur tigers - http://www.ifaw.org/russia/%D0%BD%D0%BE%...8F%D1%82-1 http://www.ifaw.org/russia/%D0%BD%D0%BE%...8F%D1%82-2 "В возрасте 15-16 месяцев, самым крупным тигром оказался Борис - его вес составил 118 кг, далее Кузьма - весом 116 кг и затем тигр Устин, весом 103 кг." 12/28/2013 At the age of 15-16 months tiger Boris weighed 118 kg, tiger Kuzma - 116 kg ,tiger Ustin - 103 kg http://www.ifaw.org/canada/news/rescued-...ast-russia http://www.ifaw.org/canada/news/how-russ...y%E2%80%99 2) tiger Boris killed two brown bears,two year old and three year old (details not reported) http://amuroopt.ru/tigryi-na-amurskoy-ze...d-spustya/ " Самец по кличке Кузя в первые дни на свободе сместился в район реки Урил Архаринского района. Он задавил крупного самца кабана: обнаружены следы жесткой схватки. Четверо суток кормился, не оставляя добычу. " "В конце августа Боря задавил трехгодовалого медведя. Илона в начале сентября на мари догнала и съела взрослого волка." Tiger Kuzma kills large male boar: traces of tough fights. Four days to feed, leaving the prey. In late august,tiger Boris killed the three-year old bear . Ilona in early September on the marsh caught and ate an adult wolf. http://www.khingan.ru/view_news.php?id=99 https://themoscowtimes.com/articles/puti...bear-48137 http://asn24.ru/news/society/6226/ 3)from April 2013 Aldrich foot snare are forbidden http://region-77-rus.livejournal.com/35897.html http://www.thepetitionsite.com/465/539/7...oot-snare/
Quality post all the way, Diamir2. Much appreciated and many thanks for the links to the articles.
I knew the young tigers had been observed in the facility where they were prepared to start a life in the wild, but couldn't find anything. The observations of Blidchenko are very interesting. She explained in what way young Amur tigers use and divide space and how they appreciate and judge situations. The experiment proves that young tigers without parents can be prepared for a life in the wild, provided the conditions are right. It also confirms the observation of Kerley and others, who wrote Amur tiger cubs disperse when they reach 18-20 months. Remarkable, as the conditions are far from easy in eastern Russia. I've read books written by people who found orphaned cubs of wild big cats. They took them home, kept them away from other people and trained them in the way their parents would. This means they walked the cubs through what would become their territory every day for many hours. In this way, the cubs got crucial information and grew in confidence. At times, their new 'parent' even had to defend them from other big cats. Later, the favour often was returned. To keep the story short: all cubs, except for a young male lion who was shot by trophy 'hunters', made it to adulthood and all of them did well. Every now and then, one of them returned to her (in most cases, the cubs were females) dad to lead him to her cubs. He wrote it was a great privilege. Billy Arjan Singh had a similar experience with a leopardess in northern India. She brought her cubs to his place during a flood. Orphaned cubs of big cats can be prepared to become wild animals in the way done in Russia, and it can be done in the way described above. The experiment in Russia shows the cubs don't need humans to succeed, meaning orphaned cubs of big cats could have more knowledge than we think. And knowledge is different from instinct. This confirms the observations of those who described the big cats as thinking animals. The only thing they really need when they're on they own and very young is protection and food. I was a bit surprised to read that Boris, at his age, was prepared, and able, to handle bears of similar age. The 2-year old bear he killed last year most probably was a brown bear, whereas the identity of the 3-year old bear he recently killed has yet to be determined. If the bear really was about 3 years of age, chances are it also was a brown bear. I'll ask the mods to move a copy of your post to the extinction thread, as it has crucial information on behaviour and food of young Amur tigers. Apollo's great thread is about individuals, whereas the extinction thread is intended for general information. I got more questions on tigers and bears, but will use the extinction thread for the reason explained above. Thanks again.
A captured wild South China tiger back in the 20th century.
 *This image is copyright of its original author
(10-03-2016, 09:50 PM)GrizzlyClaws Wrote: Do you think which other tiger subspecies they did resemble more? It's hard to compare since they haven't been spotted in so long and I haven't seen very many images of the in the wild. The coat color in your image appears to be more red, even more so than a bengal and comparable to a sumatran. But its face appears closer to the bengal than anything else.
The South China tiger supposed to be genetically closely related to the Indochinese tiger, but in the pic we saw except having more reddish coat, their facial structure is larger than those of the Indochinese tiger, and closer to that of the Bengal tiger.
That's a quite interesting phenotype that we observe from the wild South China tiger. I think those inbreeding captive specimens might not be representative of the normal population of the South China tiger.
Very nice photograph, Grizzly! One of a kind, I think. He's a bit different from the Amoy tigers I saw in books, but Amoy tigers apparently showed a lot of variation in size. The wide range (same for colour and stripe pattern) could have been a result of the description of Amoy tigers, which was a bit lacking. Maybe all tigers in the extreme south and west of China were included in Panthera tigris amoyensis when the end was near. But Panthera tigris corbetti is very different and tigers from Tonkin, not that far away, also were different. Same for those from central and northern parts of China.
Some time ago, I posted a few newspaper reports about tigers shot in the southeastern part of China in the first decades of the last century. I also posted information about the total length of a few males and females shot in that region. These tigers had been measured 'between pegs', which was quite remarkable for that region. The thing that stuck most, again, was the amount of individual variation. Same for the books I read. The books have quite accurate descriptions of Amoy tigers. I will try to find them when I have some time. At the moment, it's a bit difficult. Here's an adult female from Tierpark Berlin. The photograph was taken in 1972. Berlin has two zoos. I visited both. The zoo in the former western part of Berlin is a nice one, but I liked Tierpark Berlin better. The reasons are more room, less visitors, great scenery and many animals seldom seen in zoos. I saw rare deer, rare birds of prey (owls and quite a number of eagles, including the harpy), different bear subspecies, dholes (...), different leopard subspecies, cougars from different regions and representatives of three tiger subspecies (corbetti, sumatrae and altaica). In the days of east and west, I visited the eastern part of Berlin to buy a few books ('Saugetiere der Sowjet-Union' was one of them), watch a play written by B. Brecht and see the zoo (Tierpark Berlin). The male Amur tiger they had was the tallest captive big cat I ever saw. Many years later, I saw one who was about as tall in the facility I often visited. He was from Italy and his name was Elvis. I liked his voice and so did others, as he found a new home shortly after I saw him. Have a good look at these two photographs, as this tigress could have been the last of her kind (Panthera tigris amoyensis) in captivity. They really tried to find a male, but didn't succeed. She's very different from the captive Chinese tigers I posted about and apparently adapted to the harsh winters typical for that part of eastern Europe (at least, in those days):  *This image is copyright of its original author  *This image is copyright of its original author
The Amoy tigers did share a geographic proximity with many other tiger subspecies.
Historically, there were even Bengals lived in the southwest part of China, and that particular Amoy tiger was from that part of China, then I am not surprised that he did show some similarity with the Bengals. Even the current Asian elephant population that lives in China belongs to the Indian subspecies, and the historical Chinese subspecies of the Asian elephant was extinct long time ago. Indian Asian Elephant - Elephas maximus indicus Chinese Asian Elephant - Elephas maximus rubridens Back to the topic about the South China tiger, I also do believe they showed a lot of variation because of the genetic exchange with many other tiger subspecies with the Amur/Bengal/Indochinese, perhaps even the Caspian in the northwest fringe of China. |
| Users browsing this thread: |
| 100 Guest(s) |