There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.

07-17-2014, 01:09 PM( This post was last modified: 07-17-2014, 01:51 PM by tigerluver )

Major oversight by me, I should've described the robusticity I am analyzing, that's why I need you guys.

My definition of robusticity isn't exactly kg/cm, as allometry makes larger specimens more dense than smaller specimens intrinsically. Therefore, yes, Bengal tigers are the most dense of the subspecies in terms of literal kg/cm. Amurs would follow for second simply due to the fact they are so long, thus isometry is strongly in their favor in terms of raw density. The robusticity I am defining here takes into account isometry and allometry. I'm playing around with three dimensions in a way. Thus, what I am looking for here is what happens if I were to scale a Javan tiger to the frame of the largest Bengal, etc. That is why I use regression to see where a Javan tiger would fall on the growth trend of Bengal tigers. Thus, based on my results, a Javan tiger scaled to the dimension of the largest Bengal tiger would be 14.8% proportionately heavier. For example, a Javan version of Sauraha would be up to 300 kg.

I came to the conclusion of the zygomatic width relation based on my definition of robusticity. I'll label this term "allometric robusticity" for lack of a better phrase. When scaled up to the Bengal's dimension, the South China and Javan tiger were heavier, even though they're skulls would be thinner.

I hope I cleared that up. This whole concept is a bit difficult for me to put into words, as I don't have exact units to describe what's happening.

The South Chinese tiger and the Javan tiger now are considered as the leftover of the two large Pleistocene tiger subspecies.

We have already made a good amount of comparison between the Ngandong tiger and the Javan tiger, now let's see if we can make something between the Wanhsien tiger and the South Chinese tiger.

07-18-2014, 07:40 AM( This post was last modified: 07-18-2014, 08:09 AM by peter )

(07-17-2014, 01:09 PM)'tigerluver' Wrote: Major oversight by me, I should've described the robusticity I am analyzing, that's why I need you guys.

My definition of robusticity isn't exactly kg/cm, as allometry makes larger specimens more dense than smaller specimens intrinsically. Therefore, yes, Bengal tigers are the most dense of the subspecies in terms of literal kg/cm. Amurs would follow for second simply due to the fact they are so long, thus isometry is strongly in their favor in terms of raw density. The robusticity I am defining here takes into account isometry and allometry. I'm playing around with three dimensions in a way. Thus, what I am looking for here is what happens if I were to scale a Javan tiger to the frame of the largest Bengal, etc. That is why I use regression to see where a Javan tiger would fall on the growth trend of Bengal tigers. Thus, based on my results, a Javan tiger scaled to the dimension of the largest Bengal tiger would be 14.8% proportionately heavier. For example, a Javan version of Sauraha would be up to 300 kg.

I came to the conclusion of the zygomatic width relation based on my definition of robusticity. I'll label this term "allometric robusticity" for lack of a better phrase. When scaled up to the Bengal's dimension, the South China and Javan tiger were heavier, even though they're skulls would be thinner.

I hope I cleared that up. This whole concept is a bit difficult for me to put into words, as I don't have exact units to describe what's happening.

Let's assume you are invited for a talk about the things you're interested in. Small town local school somewhere in the US. Most of those who paid the $ 5,00 for the two-hour talk (one break and one beer included) are untrained, but not stupid by any means. Let's say experienced hunters. Entertainment is one thing, but they would want you to convince them. Tell 'm what you want to say in a few minutes. You'd have to skip regression, isometry, allometry and everything connected.

Why would an average-sized Sumatran male tiger outrobust an average male Indian tiger if he would have had a similar length, knowing he has relatively smaller dimensions in all departments? And why would he, when he would be similar in length and weight, have a smaller and less robust skull when we know that there is a positive relation between skull size and mass in Indian tigers?

Let's assume I'm in the crowd and responding to your points when you're done.

I'd say I saw a BBC-documentary on Sumatran tigers not so long ago. Wild caught adult 'problem tigers' featured and most were lean, athletic and very aggressive. My guess was not one over 300 lbs. and most well below (males). I know some of the old Dutch hunters could have seen one approaching 400 lbs. after diner, but that was over a century ago when there were thousands of tigers and very few restraints. Today, the biggest males max out at 330 lbs. or just over. At about 5.7 in head and body straight (and 8.0 in total length), that would be well below 1 kg. per cm. (head and body length). Not even close to an average Indian male (relatives).

Why would they, when upscaled to 9.3 straight and 3.1 at the shoulders standing (a century ago, but today's tigers seem to be longer as well as taller), get to 460-470 lbs. and well over empty when transferred to India? Have a look at the percentages and the relatives (referring to length and weight). Than add the fact that wild Indian tigers are both absolutely and relatively more massive than wild male Amur tigers.

In my opinion, they would need an ungrade in robusticy and the only way to get there would be some experience in wild India. As captive Indian male tigers in Indian zoos average 400-410 lbs., one could say mass has to be a result of the conditions in the reserves. It seems a high density of large prey animals, limited territories and severe competition could be the driving forces. Selection in Indian reserves, therefore, seems to be more severe than in wild Sumatra, where reserves are way larger.

While waiting for your response, someone in the crowd fancying my chances offers me a second drink. Soda, of course.

07-18-2014, 10:20 AM( This post was last modified: 07-18-2014, 10:41 AM by tigerluver )

The kg/cm unit has to be completely dropped in this situation. It isn't a valid unit for growth because an animal is characterized by volume, cm^3 (in actuality the value of 3 is more of a 3.5) in a way. I assume you get the point that larger organisms are innately more literally robust (greater ratio of kg/cm) than smaller ones due to growth in three dimensions. That's why a 310 cm cat weighs 272 kg while a 300 cm cat weight 240 kg. Mass does not grow with dimension in a one to one ratio. The kg/cm ratio of the longer cat has to be greater than the shorter cat. That's also why the smaller Sumatran tiger will look much leaner and thinner then say, a 250 kg prime male Bengal. Not because the Bengal species is proportionately heavier at equal sizes.

In simplest terms, here's a microcosm what's happening, based on live, actual specimens. A Bengal tiger of length 251 cm weighs 115 kg (Sunquist, 1981). A Javan tiger of length 248 cm weighs 141 kg (Mazak, 1981). At equal dimensions, island tigers carry more mass.

Now let's do some math. No regression. I'll prove to you that even the largest Bengal tigers do not carry as much weight (kg) in their volume (cm^3 or with true scale factor, cm^3.5) as the Javan. Just take some numbers and find density. That's the most simplistic word I overlooked when describing the value I am measuring.Take the approximate scale factor of mass growth in tigers, 3.5.

Let's get the big male Sauraha as our Bengal tiger ambassador. 310 cm, 272 kg (we'll give him is highest weighted mass rather than his official 261 kg just to remove any doubt that Javans are denser).

A large male Javan tiger is 248 cm and 141 kg. Our density unit, kg/cm^3.5.

Let's see who is more dense.
Sauraha: 272 kg / (310 cm)^3.5 = 5.19e-7 kg/cm^3.5.
Javan: 141 kg / (248 cm)^3.5 = 5.87e-7 kg/cm^3.5.

07-18-2014, 09:46 PM( This post was last modified: 07-18-2014, 09:47 PM by Pckts )

The only factor would be muscle densisty compared to fat. One of these specimans could be ''fatter" and while being heavier, may not be "denser."
In terms of view to the naked eye and as a physical powerful speciman.

07-18-2014, 11:35 PM( This post was last modified: 07-18-2014, 11:36 PM by tigerluver )

As all the data is derived from wild specimens, obesity should not be problem. Though, the Caspian and Amur tigers may be less dense than what is already shown, as fur and fat weight is probably higher as you pointed out. For the tropical forms, they're all lean muscle.

How much truth is there to the Javan tiger having larger paws than specimens for Nepal? If it's true, what do you think the purpose or cause of this is?

Large paws are known to act as "snow shoes." There hasn't been snow in Java for millenia. From my discussion with the professor who examined the Javan fossils, she believes these forms essentially evolved into the modern Javan form. Occupit similarities also support this claim.

Maybe the evolution of the Sonda tiger was rushed for whatever reason. Once the oceans rose, the larger specimens stuck on the island probably could not survive for long, and the extreme downsizing began. Is it possible that the large paws of modern Javans are a remnant of their giant ancestors?

In fact, some pictures show that the paw of the Javanese tiger was of normal size, compared with other tigers. However, other images show very large paws, comparable to those of the Amur tiger.

Check what Hoogerwerf (1970) states about the Javanese tiger pugmarks:

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What do you think, guys? [img]images/smilies/tongue.gif[/img]

07-29-2014, 08:37 AM( This post was last modified: 09-07-2020, 10:24 PM by peter )

tigerluver\ dateline='\'1405659026' Wrote: The kg/cm unit has to be completely dropped in this situation. It isn't a valid unit for growth because an animal is characterized by volume, cm^3 (in actuality the value of 3 is more of a 3.5) in a way. I assume you get the point that larger organisms are innately more literally robust (greater ratio of kg/cm) than smaller ones due to growth in three dimensions. That's why a 310 cm cat weighs 272 kg while a 300 cm cat weight 240 kg. Mass does not grow with dimension in a one to one ratio. The kg/cm ratio of the longer cat has to be greater than the shorter cat. That's also why the smaller Sumatran tiger will look much leaner and thinner then say, a 250 kg prime male Bengal. Not because the Bengal species is proportionately heavier at equal sizes.

In simplest terms, here's a microcosm what's happening, based on live, actual specimens. A Bengal tiger of length 251 cm weighs 115 kg (Sunquist, 1981). A Javan tiger of length 248 cm weighs 141 kg (Mazak, 1981). At equal dimensions, island tigers carry more mass.

Now let's do some math. No regression. I'll prove to you that even the largest Bengal tigers do not carry as much weight (kg) in their volume (cm^3 or with true scale factor, cm^3.5) as the Javan. Just take some numbers and find density. That's the most simplistic word I overlooked when describing the value I am measuring.Take the approximate scale factor of mass growth in tigers, 3.5.

Let's get the big male Sauraha as our Bengal tiger ambassador. 310 cm, 272 kg (we'll give him is highest weighted mass rather than his official 261 kg just to remove any doubt that Javans are denser).

A large male Javan tiger is 248 cm and 141 kg. Our density unit, kg/cm^3.5.

Let's see who is more dense.
Sauraha: 272 kg / (310 cm)^3.5 = 5.19e-7 kg/cm^3.5.
Javan: 141 kg / (248 cm)^3.5 = 5.87e-7 kg/cm^3.5.

Who's denser? The Javan, by 13.1%.

Much appreciated, tigerluver. Agreed with the first part of your post, but the problem, of course, is enough accurate and reliable data. Most unfortunately, there isn't much about the size of Sunda tigers in documents.

Although I assume you saw the scans already, I decided for a repost of the tables from Sody (1949). Maybe you could compare the skulls of P.t. tigris, P.t. sondaica and P.t. sumatrae to get to a prediction regarding weight and relative robustness.

I have no clue as to Java tigers, but the average I found for wild adult Sumatran males was between 115-120 kg. about a century ago (total length straight 7.11). Today's wild tigers, like in India, could be heavier (two males recently weighed were 148,2 and 150,0 kg.), but I doubt if they are longer.

1 - SODY

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2 - SUMATRA TODAY

2a - 150,0 kg.

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2b - 148,2 kg.

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2c - Denning (weight unknown, but the most massive he shot in the thirties of the last century - this tiger ambushed, killed and consumed an adult male sun bear)

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2d - Auckland Zoo captive Sumatran male tiger

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3 - INDIAN TIGERS

3a - The Sauraha tiger (Chitwan, Nepal - 310 cm. 'over curves' and over 600 pounds not adjusted the last time they sedated him)

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3b - Unknown male India (watch the skull)

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3c - Madla (Central India - this tiger bottomed a 550-pound scale)

I'm much too tired for a proper response to match your great post Peter, but out of respect, I'll try to share some thoughts and add on later.

For sure the sample size is not large enough, probably never will be. If I remember correctly, the Bengal database is of almost 30 specimens. Only one Javan specimen has been recorded and that's all I could use as reference. I had more specimens of Sumatran and South China to use for analysis. Like I stated earlier, +/- 5% in density difference isn't too significant to me (I can show hypothesis tests later), and so the Sumatran tiger might not really be the model for our prehistoric forms. The striking differences are in the Bali, Javan, and South China forms because they are 9.8+ %, enough for me to call significant in my opinion.

For my purposes, the robusticity calculations are more of a correction factor. I am almost certain that some modern male Bengals are as robust as the island tigers. The relatively long specimens of the early 1900s are a bit less bulky than say, Sauraha, density-wise. If I'd get my hands on enough of the large modern specimens probably no density factor would be needed and the uncorrected estimate would still probably range from 470-500 kg. Maybe the predator-prey density ratio plays a strong part in how dense the specimens are. Ironically, less tigers has lead to bigger tigers, and maybe this is due to the predator-prey ratio approaching prehistoric values, just not in the way us conservation savvy folk would have hoped.

On a separate note, to address the Anyonge equation coincidence with my latest estimate some may be wondering about. It really just comes down to how that equation ended up giving the right values had the specimen been a dense island tiger. The Copenhagen specimens used by Christiansen and Harris 2009 are light. A specimen (230 kg) a bit longer than Sauraha (270+ kg) was at least 40 kg lighter. The Anyonge formula gave an estimate of 290 kg for the specimen. This is where the Anyonge equation overestimation conclusions comes from. So for starters, the 290 kg estimate from Anyonge isn't too bad for Sauraha. Add to that, Sauraha isn't the most dense of specimen eithers judging by the Javan comparison and even his own neck girth (10 cm thinner in circumference than Madla). Taking into account all this, a dense specimen the size of Sauraha could reasonably be 290 kg. Extend that to the 350 cm specimen, and 470 kg isn't out of the question.

It all comes down to database, database, database. Bone dimensions are sometimes messy and weight is too sensitive to them due to small sample sizes. I myself have only been able to measure and add 3-4 more small tiger (the largest specimen was only 125 kg) specimen skeletons to my database. Body dimension reconstruction from a long bone or two seem more reliable to me from what I've gotten. So at this point, I've stuck with the Kurten method of reconstructing the body frame from the bones then applying it to a much larger database of body lengths and the correlating masses.

Tigerluver, could you tell me which is the method of Kurten for the reconstructing of the body frame from the bones? I am VERY interested in this. [img]images/smilies/biggrin.gif[/img]

Sorry for the late reply, I got sick for weeks and forgot about the thread.

The Kurten method is simply reconstructing body size from bones then applying body size to body mass. Estimates are better reflective of wild specimens this way as bone to body size is consistent in captivity and wild, but no weight. Moreover, due to the sensitivety of mass, the Kurten method can be more powerful as the modern database for in the flesh size to mass in much larger than what we have on bone to mass (I've expanded the database on tiger bones to 7 specimens, courtesy of the Smithsonian. The problem, these aren't purebred specimens and are exceptionally light, not well reflective of the wild populations). Kurten used this method in one of the first estimations of the Short-faced bear. Today, his estimates seem to be underestimates, but the reason to this is easy to explain. Kurten (1967) used a proportionately light variety of bear, either the sun bear or the sloth bear, I can't remember which one off the top of my head.

Radius to humerus ratios have a strong correlation to the relative robusiticity and density of a species.

This table is from Big Cats and Their Fossil Relatives by Mauricio Anton.

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Note how low the ratio is for Smilodon, supporting the idea that this is a freakishly robust animal.

Diedrich (2011) mentions a female specimen of P. spelaea spelaea with the following dimensions:

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Thus, the radius/humerus ratio for this holotype is 0.903, essentially identical to the modern lion. I'm slowly becoming more inclined to accept the "leo" addition to the cave lion name. Skull differences are even found between the tiger subspecies, and might be a better characteristic for subspeciation rather than speciation. Body-wise, the lion and P. spelaea sit in exactly the same unique class. The jaguar and leopard are far, far off from even P. atrox in body characteristics.

Tigerluver says: ~
Now the point we all love, mass. The Smilodon humerus is about 3% shorter and 6% wider than the bear humerus, leading me to believe we have a specimen which probably weighed around the bear's mass. Of course, Smilodon being built differently from a cat and a bear in terms of dimensions (e.g. the sloping back) would likely have an effect on mass. But from what we have available, the bear bone is a good reference point. So, what do you guys think? Tigerluver, you have sparked my curiosity. Can you give us more info on Smilodon populator?

08-30-2014, 04:40 AM( This post was last modified: 09-10-2014, 09:52 AM by tigerluver )

I've prepared something more on Smilodon with bears as comparison, will post that ASAP.

Also, here's a surprise, the true 480 mm Ngandong femur. No distortions or anything, just what von Koenigswald photographed and published in his book (yes, unfortunately the page had to be ripped out for a perfect scan).

*This image is copyright of its original author

Edit: Here are the details on this femur.

To find the measurements, I myself used a pixel to pixel method on a high resolution scan of the page. For sharing purposes, I added a ruler for people to see. Unfortunately, it seems the photo quality degraded uploading a bit.

At first, the discrepancy in the distal measurement here and the one published worried me a bit. So I explored the possibility of a typo. I did the math and concluded a typo wasn't possible. If the distal extremity were 88 mm on this bone, then the proximal greatest diameter would be 91.6 mm, and the total length 393.4 mm. 2 typos in one has a 0% chance. Add to that, this is one of the two pages in the book which doesn't utilize an actual size scale. Upon further research, the measurement is from below, literally on the transverse plane.

Compared to modern comparative data, specifically the database of Christiansen, two values here are comparable, the length and the distal AW. The epicondylar index of this specimen is .223, out of the range of logged Amur and Bengal forms by a good amount (.183-.199). The database of Javan and Sumatran specimens comes closer to this value (.193-.212). I rescind my previous conclusions after getting my hands on wild, island form long bone data, and it seems larger epicondylar indices do correlate a bit with relative body density.