Tetrapod Zoology

‘Revising’ the Siberian tiger

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Dave Hone – who’s had more than his fair share of mentions here at Tet Zoo over the past several days – accompanied me on a visit to Marwell Zoo yesterday. We had a great time, but unfortunately got all too little paper-writing done :) (after all, this is what scientists normally do when they meet up). There’s always something new to see, or experience, at the zoo. The Frill-necked lizards Chlamydosaurus kingii were brand-new, for example: it was in fact only their second day on exhibit. And I’ve never heard a Snow leopard Panthera uncia roar before. It didn’t sound like any other big cat roar, and in fact I can’t begin to describe what it did sound like. By strange coincidence, the male Pygmy hippo Hexaprotodon liberiensis also did some loud vocalisation, and again this was a first for me. But the coolest thing concerned the Siberian tigers…

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As should be obvious from these photos, one tiger was particularly grumpy and repeatedly ‘attacked’ the glass. It did this several times, providing some great photo opportunities. I don’t know what motivated this behaviour: in general, big cats learn to ignore the constant taunting they must get from kids and other annoying humans. But it was very cool.

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ResearchBlogging.org

Incidentally, the zoo world underwent a concerted effort a few years ago to get the Siberian tiger P. tigris altaica re-branded with one of its alternative names, Amur tiger. This hasn’t been too successful, and ‘Siberian tiger’ is still used more widely (at least, it is in the English-speaking world). Wild Siberian tiger exhibit low genetic variability and seem to be bottlenecked (Russello et al. 2005). This was thought to be the result of human persecution (during the 1940s, the wild population was down to 30-40 individuals. It’s now somewhere round about 200 animals according to WWF, though pre-2000 estimates were as high as c. 500). The global captive population (of about 250 individuals) is, rather unusually, more diverse genetically, so it might be that the founders of the captive population were captured before bottlenecking occurred.

However, recent work indicates that the Siberian tiger is a very young subspecies anyway (less than 10,000 years old) and that it only recently evolved from wandering populations of the almost certainly extinct Caspian tiger P. t. virgata (Driscoll et al. 2009) [captive Caspian tiger show below. This individual photographed at Berlin Zoo in 1899]. If this is valid, then the Siberian tiger may not have had much genetic variation to begin with. More importantly, perhaps, is that Caspian and Siberian tigers previously had a continuous range, were very similar in terms of habitat and natural history, and were extremely similar genetically: given this data, it might be argued that they should be regarded as synonymous. If this becomes accepted (see Driscoll et al. 2009), then (1) P. t. virgata is the correct name for the Caspian + Siberian tiger population (because P. t. virgata Illiger, 1815 predates P. tigris altaica Temminck, 1884) and (2) P. t. virgata is not extinct after all, just locally extinct across much of its former range (you may know that alleged sightings of P. t. virgata continue across its former range, despite its supposed extinction during the 1950s 1970s).

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Incidentally, this work is another demonstration of the fact that phylogenetic work can have a major impact on conservation strategies and wildlife management (because, if Caspian and Siberian tigers are the same thing, ‘Siberian’ tigers can be re-introduced to parts of the Caspian tiger’s former range).

PS – Driscoll et al. (2009) did not support the view of MazŠk & Groves (2006) that the Sumatran tiger P. sumatrae and Javan tiger P. sondaica should be regarded as distinct species relative to P. tigris.

Ref – -

Driscoll, C. A., Yamaguchi, N., Bar-Gal, G. K., Roca, A. L., Luo, S., Macdonald, D. W., O’Brien, S. J. (2009). Mitochondrial phylogeography illuminates the origin of the extinct Caspian tiger and its relationship to the Amur tiger. PLoS ONE, 4 (1), e4125. doi: 10.1371/journal.pone.0004125

MazŠk, J. H. & Groves, C. P. 2006. A taxonomic revision of the tigers (Panthera tigris) of southeast Asia. Mammalian Biology 71, 268-287.

Russello, M. A., Gladyshev, E., Miquelle, D. & Cacconne, A. 2005. Potential genetic consequences of a recent bottleneck in the Siberian tiger of the Russian Far East. Conservation Genetics 5, 707-713.

Comments

  1. #1 David Marjanovińá
    February 28, 2009

    ‘Siberian tiger’ is still being used more widely (at least, it is in the English-speaking world)

    Also in German and AFAIK French. “Amur tiger” is all I’ve ever seen in Russian, though.

  2. #2 Alan K
    February 28, 2009

    Very nice photo pun at the top with a very alert and interested “hippotigris” as the center individual.

  3. #3 Laelaps
    February 28, 2009

    “Incidentally, the zoo world underwent a concerted effort a few years ago to get the Siberian tiger P. tigris altaica re-branded with one of its alternative names, Amur tiger. This doesn’t seem to have been too successful”

    I’m doing my part.

  4. #4 Mike Keesey
    February 28, 2009

    Incidentally, this work is another demonstration of the fact that phylogenetic work can have a major impact on conservation strategies and wildlife management (because, if Caspian and Siberian tigers are the same thing, ‘Siberian’ tigers can be re-introduced to parts of the Caspian tiger’s former range).

    To sort of continue a thought from the “FOUR Anacondas” post’s comments (but in a less philosophical and more biological direction) — what exactly does it mean for them to be “the same thing”? Wouldn’t Siberian tigers comprise a population whether that population is a subpopulation of the Caspian tigers or not? Or are you suggesting there was significant flow between Siberian and other Caspian tigers?

    I find it strange that conservation relies so heavily on concepts like “species”, “subspecies”, etc. when those terms are so ill-defined. Clearly these units are efforts at capturing some real aspect of biodiversity, but I feel that there has to be a better way to define such units. (Just a feeling, though — I’m far too unlearned to have an actual suggestion. Well, maybe something to do with metric balls, but I’m not sure what the metric would be.)

    (Side note: one of our cats is named “Caspian”. Fortunately, she’s not extinct yet.)

  5. #5 Ville Sinkkonen
    February 28, 2009

    First time I heard the “roar” was also the funniest moments I have experienced in zoo.
    I walked along so called “cat valley” which is the area where all of the cats, big and small, are kept.
    I stopped to see the snowleopards since they seemed pretty active at the time (all but one which was curled up in a corner biting it’s own tail). One of them climbed to highest point it could find and in “lion king” fashion got ready to roar, but instead of deep rumbling sound that I was expecting it was almost like housecat meow.

  6. #6 Ross Barnett
    February 28, 2009

    Great post about an important paper. Why it was only in PLoS one I dont know.
    The Caspian Tiger did hang around until the 1970s though. One was killed in Hakkari province in Turkey in 1970.

  7. #7 Mo Hassan
    February 28, 2009

    An Amur tiger (see, I didn’t say “Siberian”, haven’t done for years except to most other people) peed on me through the wire mesh of its enclosure once about 10 years ago, and I think I caught it on film but since lost it. I seem to remember it smelling strongly of musk, but not entirely unpleasant, unlike domestic cat wee. They seem to be more entertaining, although less photogenic, than Sumatran tigers.

    I got a bit too close to a dozing snow leopard in another zoo and it growled at me, but I don’t remember it sounding odd?

  8. #8 Dave Hone
    March 1, 2009

    Well if you don’t want to keep mentioning me, stop using all my amazing snake photos, or even pictures *of* me! ;-)

  9. #9 derek
    March 1, 2009

    As a layman, I don’t understand why you would want to abolish the later species of tiger after discovering that it was just part of a larger earlier population of another species, that was geographically isolated and then experienced changes while isolated that caused it to look different from the original. I thought the word for that sequence of events was “speciation”?

  10. #10 David Marjanovińá
    March 1, 2009

    The questions are whether it was isolated and whether it looked different from the original. You might like to read the post again…

  11. #11 Metalraptor
    March 1, 2009

    Therin lies the biggest problem with cladistics. For example, (sorry for using a non-tetrapod response) genetic research has shown that king crabs are nestled within the hermit crab genus, Pagurus. There are three solutions to this, all equally absurd. One, we could sink the king crab species within Pagurus. Two, we could split up Pagurus, along the lines of which ones are closer related to Pagurus, but that would also be absurd, as they are barely distinguishable. Third, make the genus Pagurus paraphyletic. Aaargh, can we not find an acceptable classification system!

  12. #12 Christopher Taylor
    March 1, 2009

    Therin lies the biggest problem with cladistics.

    Sorry, I’m not quite understanding what is the target of your ire there. Are you complaining about cladistics (which is a method of predicting relationships) or phylogenetic nomenclature?

    Identifying what actually happened evolutionary-wise is one thing. Deciding how to express what happened as a classification is another.

  13. #13 Hai~Ren
    March 1, 2009

    Interesting. Some articles I read recently I had been led to believe that the mainland Asian tiger subspecies formed a single contiguous population that differed morphologically due to climate, prey availability and competition with other predators.

    I would have thought that the Amur tiger was most closely related to the South China tiger due to proximity, and that the Caspian tiger was either one of the most basal or most derived due to its geographical isolation. It’s very interesting to see how this paper presents a very different picture of tiger dispersal across the continent.

    Similarly, I would have thought that the Malayan and Sumatran tigers to be closely related to each other, though it appears that this is not the case. Interesting to note that the South China tiger is the most basal, and that the Sumatran was the next one to diverge before the other mainland Asian subspecies. Is it possible that there were multiple waves of dispersal of tigers through Indochina and the Malay Peninsula, with the extant subspecies having replaced populations that went extinct in prehistoric times?

    So it seems that the South China tiger is a relictual population surrounded by more derived populations. I wonder how much genetic introgression has taken place both from the south (Indochinese), north (Amur), and west (Caspian)

  14. #14 Hai~Ren
    March 1, 2009

    Looking at the wealth of grammatical errors in my previous comment, I now realise how important it is not to leave comments before one has fully woken up.

  15. #15 Mo Hassan
    March 2, 2009

    For me, the easiest subspecies of tiger to identify is the Sumatran, because of its face. This suggests, to me, that it is more different to the mainland races than any of them are from each other. It makes sense then that the Sumatran, and probably also the extinct Javan and Bali subspecies, would be phylogenetically distinct from the rest of the tigers.

  16. #16 Nathan Myers
    March 2, 2009

    I, for one, find Dave Hone at least as interesting as any actual tetrapod.

  17. #17 Hai~Ren
    March 2, 2009

    What’s up with that “islam sohbet” spambot that copied a sentence of my comment and reposted it?

  18. #18 Graham King
    March 3, 2009

    I, for one, find Dave Hone at least as interesting as any actual tetrapod.
    Posted by: Nathan Myers | March 2, 2009 2:14 PM

    er, Nathan, surely Dave actually is a tetrapod himself? (checks photo)…unless missing a limb or two, unknown to me?

    Brilliant stuff Darren! I immediately went and read that paper.

    In it I read of

    clouded leopard (Neofelis nebulosa) [14], leopard (Panthera pardus) [15] and snow leopard (Panthera uncia)

    Re clouded leopard: this was unfamiliar to me; if I ever did read the name before I may have thought it synonymous with snow leopard.

    Struck that clouded leopard was a different genus to leopard and snow leopard, I took a look via Wiki to read up and see a video of it. Wow! Beautiful. That coat looks particularly cryptic… say among forest floor litter.

    Re Snow leopard:

    -I am curious to see 3 synonyms Panthera uncia, Felis uncia and Uncia uncia. 3 synonymous generic names, one specific name… Is this unusual?

    Ville Sinkkonen said:

    …roar, but instead of deep rumbling sound that I was expecting it was almost like housecat meow.

    -Is a less-roaring call
    (a) adaptive per se? (eg guessing… in habitat where prey densities are presumably scarcer, is it maladaptive to roar so loudly due to risk of scaring prey away? yet.. scarcity would suggest larger ranges and need for louder call audible over greater distances between individuals? especially if in thinner air…)
    or
    (b) a mere side-effect of a change that is adaptive for another reason (eg different throat/larynx morphology or breathing pattern suited to colder/thinner air where it lives?)
    (c) a quirky effect of bottlenecking (founder effect, chance descent from one ‘unusually quiet’ individual – I notice that domestic cats have very variable individual miaow-characteristics?
    (d) is this quietness innate genetic, or environmentally-conditioned, or culturally-trained, difference?
    (e) could snow leopards roar loudly but maybe just don’t realize it?!
    (I’m serious. Our family spaniel howled like a wolf – but only twice in her life that I know of, and both times were in her sleep?!! Awake, did she not realize she could howl? or did she just never have a real-life social trigger to do so?)

    Ok, that’s enough matters arising. See how interesting your blogs are, Darren? Stirring all this thought?!

  19. #19 Nathan Myers
    March 3, 2009

    Graham: surely Dave actually is a tetrapod himself?

    That’s a hypothesis I’m happy to entertain, but we’re supposed to be scientists around here. What experiment can we conduct that will settle the matter? “Tetrapod” is a matter of ancestry, so counting limbs is out. Are any tetrapods known that are demonstrably ancestral to Dave?

    For my part, in the interest of comity, I am willing to hold claims of my own tetrapodality in abeyance until the matter is settled.

  20. #20 David Marjanovińá
    March 3, 2009

    I am curious to see 3 synonyms Panthera uncia, Felis uncia and Uncia uncia. 3 synonymous generic names, one specific name… Is this unusual?

    Not at all. It just means there’s a bit of history here: originally all cats were put into Felis, then the big cats were separated as Panthera, and then the snow leopard was taken out of Panthera for being too different.

  21. #21 Jerzy
    March 3, 2009

    Hi Darren,

    Congratulations for daughter! Cute little tetrapod indeed!

    Tigers shows that, if anything, molecular studies cannot replace old-fashioned morphological subspecies for practical and conservation purposes. Tiger subspecies are pretty close genetically. But ecologically they are non-replaceable. Tropical tigers couldn’t survive Siberian winters, nor Siberian tigers could live in hot tropical climate. If anything, less related but tropical Indian, Malayan and Sumatran tigers can better replace each other ecologically than Siberian and Indian ones.

    BTW – this paper also suggests that Amur tiger is indeed ‘Siberian’, because tigers roamed all south Siberia between Caspian Sea and Amur region in recent times.

  22. #22 Dartian
    March 6, 2009

    Ross Barnett:

    The Caspian Tiger did hang around until the 1970s though. One was killed in Hakkari province in Turkey in 1970.

    The original reference for that is Baytop (1974), who saw and photographed the pelt of a tiger supposedly shot in Hakkari Province (extreme SE Turkey) in February 1970. In addition, both this source and Kumerloeve (1974) claim that a few tigers were shot (or rather, poached) in Turkey even after this date.

    References:

    Baytop, T. 1974. La présence du vrai tigre, Panthera tigris (Linné, 1758) en Turquie. Säugetierkundliche Mitteilungen 22, 254-256.

    Kumerloeve, H. 1974. Zum Vorkommen des Tigers auf t√ľrkischem Boden. S√§ugetierkundliche Mitteilungen 22, 348-350.