|
Amur Tigers
|
 (08-13-2019, 12:11 AM)Spalea Wrote: Are you sure that this is an Amur tiger, as opposed to a Bengal tiger in the Himalayan region, such as in Bhutan? Without the information in these webs, these pics of Bhutanese tigers are quite certain to trick people into thinking that they're pics of Siberian tigers: https://www.iucn.org/news/species/201707...ers-bhutan, http://tigers.panda.org/news/bhutan-comm...ld-tigers/  *This image is copyright of its original author  *This image is copyright of its original author  *This image is copyright of its original author
@BorneanTiger :
About #543: Yes, perhaps you're right, I have no one certainty that it's an Amur tiger. But as concerns the Bhutan tigers, I remind some documentaries about them, they don't live the whole year under cold climates or above 4000 meters high. Thus I don't believe they enjoy a fur as thick as on the photo I posted at #542... Perhaps too the Amur tiger's fur is lighter in colour than the Bhutan tiger. But in this case I cannot really determine if it's the case with the photos of your linked account. I can be wrong I confess it.
Amur tiger spotted in China, looks like to be night between August 13th-14th.
https://shanghai.ist/2019/08/14/taxi-driver-spots-rare-siberian-tiger-by-side-of-jilin-highway/ Also video footage about it, low quality and after 0:23 no more footage about tiger, just some odd animations... Another, maybe a bit better quality. (08-26-2019, 03:03 AM)epaiva Wrote: So this is from 1999, right? And is this what they thought at that time to be wild Siberian tigers or is this information about captive tigers? This is after all very different when comparing to it,what they found out in that project in which they weighed wild tigers in Russia and which was published 2005.  (08-26-2019, 04:47 PM)Shadow Wrote:Yes this information is of captive Siberian Tigers, I received it in 1999. I was moving some of my books yesterday and found it.(08-26-2019, 03:03 AM)epaiva Wrote: (08-26-2019, 05:55 PM)epaiva Wrote:(08-26-2019, 04:47 PM)Shadow Wrote:Yes this information is of captive Siberian Tigers, I received it in 1999. I was moving some of my books yesterday and found it.(08-26-2019, 03:03 AM)epaiva Wrote: Ok, pity that not mentioned where was that 306 kg tiger. It would have been nice to find photos and see condition of it.  (08-26-2019, 06:01 PM)Shadow Wrote: Ok, pity that not mentioned where was that 306 kg tiger. It would have been nice to find photos and see condition of it. Actually, it seems that the letter just copy-paste the information from Mazák. About the tiger of 306.5 kg, it was a captive male named "Circa" and belonged to the Bougline Menagerie, the record came from the year 1960. It was reported by Mazák in his book "Der Tiger" in page 188-189 of his book (reprint of 2013 from the edition of 1983). Maybe @peter can give a better translation of that specific part, as he do read German.  (08-26-2019, 06:01 PM)Shadow Wrote:(08-26-2019, 05:55 PM)epaiva Wrote:(08-26-2019, 04:47 PM)Shadow Wrote:Yes this information is of captive Siberian Tigers, I received it in 1999. I was moving some of my books yesterday and found it.(08-26-2019, 03:03 AM)epaiva Wrote: V. MAZAK - DER TIGER (1983) V. Mazak was one of the first who collected a lot of reliable information on the size of tigers. With 'reliable', I mean he, in the third edition of his book, only used records of tigers measured in a straight line ('between pegs'). As far as I can see, Melinda Jessen used Mazak's book to answer Epaiva's question on the size of Amur tigers. Here's a few examples (regarding Amur tigers) for those who have Mazak's book: 1 - Total length: pp. 162-163 and 183-188 2 - Weight: pp. 163 and 183-190 3 - Standing height: pp. 179-181 4 - Skull length: pp. 162, 190-195 SIZE OF AMUR TIGERS Mazak's book is extensive and interesting, but the chapter on size (pp. 178-196) is a bit confusing at places. Mazak used information of both captive and wild tigers to get to averages. Not a few of them were large or very large. The result was impressive averages. Let's take weight as an example. His average for male Amur tigers (233,4 kg. or 514 pounds) is based on weights of 11 wild male Amur tigers and 1 captive tiger (n=12). The captive tiger, at 306.5 kg. (675 pounds), was the heaviest by a margin. Although the weight is reliable, the tiger was exceptional. If you use the weight of an exceptional captive male tiger in a table with 12 individuals only, chances are it will affect the result. The wild tigers were 245, 250, 184, 196, 217, 195, 270, 250, 221, 217,5 and 249,1 kg. (pp. 189). Reliable weights? In a document on the reliability of historic records (of wild Amur tigers) published in 2005, most of the weights used by Mazak were classified as 'unreliable'. In spite of that, Mazak's average was very close to the 'historic average' of wild male Amur tigers. MIXING RECORDS OF WILD AND CAPTIVE AMUR TIGERS Is mixing records of captive and wild Amur tigers unsound? Yes. One reason is captivity has a profound effect on big cats. Not seldom, captive big cats are quite different from their wild relatives. Another reason is wild Amur tigers decreased in size after, say, 1970. Captive Amur tigers in European zoos are descendents of wild tigers captured before 1970 (referring to Studbook Amur tigers). Based on what I have, I'd say they're larger than their wild relatives. Why did Mazak, a zoologist, decide to mix records of captive and wild Amur tigers? My guess is he did so as a result of a lack of data. Today, we know a bit more about the size of wild Amur tigers, but in the last decades of the previous century they were an enigma in most of Europe and the USA. SIZE OF WILD AMUR TIGERS There's only one table that has reliable information on the size of wild Amur tigers today. It was published in 2005, meaning it is based on measurements of wild tigers captured in the period 1992-2004 (the Siberian Tiger Project started in 1992). Although the table has a few young adults and so-called 'problem tigers', the averages of males of 3 years and older (176-177 kg. and 294 cm. in total length measured 'over curves') could be quite close to the mark. Although some wild male Amur tigers captured in the period 2005-2018 were quite large, not one of them even approached 500 pounds (226,8 kg.). Individual variation, in contrast to other subspecies, seems to be quite limited. Wild male Amur tigers today also seem to be shorter than wild male Amur tigers a century ago. Those captured in the period 1992-2004 averaged 294 cm. in total length measured 'over curves', meaning they are 280-281 cm. in a straight line. About as long as the male tigers shot by the Maharajah of Cooch Behar and his guests about a century ago. I never saw a table with reliable information on the size of captive male Amur tigers, but the information I have strongly suggests they are longer than their wild relatives. The 3 captive male Amur tigers I measured (280, 287 and 294 cm. 'between pegs') were a bit shorter than most. Large males well exceed 300 cm. in total length 'between pegs' and reach 100-110 cm. at the shoulder while standing. Most captive males range between 400-500 pounds (181,44-226,8 kg.), but some exceed 600 pounds (272,16 kg.). One of the Prague zoo tigers measured by V. Mazak had a head length of 45 cm., but the Duisburg zoo tiger, although shorter in head and body, had a head length of 50 cm. Tiger 'Igor' of the Odense zoo also had a large head. Most Studbook Amur tigers are descendents of wild Amur tigers captured in the period 1945-1970. According to those in the know, the size of Amur tigers declined after 1970. If true, it should show in the captive Amur tigers in European zoos meaning they should be larger than their wild relatives today. As this seems to be the case, they, albeit in an indirect way, more or less confirm the hypothesis on the decline of the size of wild Amur tigers. Any evidence of large individuals shot before 1970? The document on the reliability of historic records of wild Amur tigers published in 2005 (see above) has many records of large wild Amur tigers. Most were dismissed for good reasons, but that doesn't mean these records were a result of imagination. In spite of all dismissals, the historic average of wild Amur tigers was quite impressive (230-240 kg. for males). Could it be similar to the average of Amur tigers in European zoos today? I don't know, but my guess is the difference is limited. Wild tigers, if anything, should be a bit larger. The reason is more opportunities and more competition. FUTURE I'm not sure, but my impression is captive Amur tigers (in European zoos), sizewise, also seem to go downhill. I'm not the only one who noticed the giants occasionally seen in the sixties, seventies and eighties of the last century are gone. Some of the captive Amur tigers I saw back then seemed out of this world. They also had a very different attitude. But you never know. I read reports about plans to create new forests just about every other day. It seems humans have finally realized climate change and extreme weather conditions are very real threats. Something needs to be done and it needs to be done now. Could Manchuria be transformed into the sea of forest Baikov saw a century ago? The Chinese, although still a bit hesitant, seem to be serious about reforestation and creating new reserves. Same for the Russians. If wild Amur tigers have 300 000 square km. of forest at their disposal, anything is possible. But human-induced stress needs to be removed as well and Amur tigers also need the genes of their captive relatives to overcome the problems created during the bottleneck in the first decades of the previous century (referring to the limited amount of individual variation seen today). They need to be very fit if they want to hunt the mighty Ussuri wild boar. There seems to be a connection between big cats, size and wild boars. Rainforest leopards are large. According to Chui, pigs could be the reason. That, no other serious hunters and competiton for females. I saw a number of skulls of leopards shot in rainforests in central and western Africa. The teeth in particular were large and robust. Not that different from Amur tigers. |
| Users browsing this thread: |
| 57 Guest(s) |