Size comparisons

[GuateGojira]

(05-22-2022, 02:39 PM)LonePredator Wrote: @GuateGojira Hello Guate, I was looking at your size data about Ussuri Brown Bears and Yellowstone Grizzlies and I noticed something interesting. I wanted to ask you which sample the length and height of the Grizzly been taken from? The 193kg sample or 245kg sample? And which one for the Ussuri Brown Bear?

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

*This image is copyright of its original author

As you can see, the length and height of the Ussuri Brown Bear outsizes the inland Grizzly by a huge margin but the weights of both are still so similar. How could this be possible? Is it because of different samples for weights and measurements or is it due to food shortage for the Ussuri Bears because the Ussuri Bear measurement also shows a low chest girth in relation to its length and height.

With the length and height the Ussuri Bear has, it could most likely achieve very high weights such as 300-350kg given the right conditions and I think this is perhaps the same weight as the average Kodiak or Alaskan Peninsula Bear.

One more interesting thing to note is that ursids and felids do not burn muscle mass like humans do due to lower amounts of myostatin, dense and thick bones and a combination of other factors. Even after hibernation when Bears lose a lot of weight, the loss of muscle mass in Bears is still almost negligible.

My point here is that the Ussuri Bear should have a lot more strength than the inland Grizzly since the Ussuri Bears may not have as much fat but it would still retain most of its muscle which would give it that level of strength while a lot of the inland Grizzly’s weight is still made up of fat. The Ussuri Brown Bear could likely have the level of strength only slightly less than the giant Alaskan Peninsula and Kodiak Bears.

Even the pictures you have used in the comparison shows a giant Ussuri Bear with huge skull and overall body dimensions but it looks like it’s starving while the Grizzly is small in overall dimensions but looks quite fat which suggests that the overall absolute muscle mass in the Ussuri Brown Bear should be much much higher than the Grizzly.

These images are old and outdated, specially the one from the Russian bear, however the one of the American bear is still ok.

About the data of the Grizzly, the source is: Blanchard, 1987. Size and growth patterns of the Yellowstone Grizzly bear. Measurements used in the images are the ones taken in straight line.

About the Russian bear, the data came from an article of S. P. Kucherenko in the 70's, and the article was published in a webpage in 2003. Sadly the webpage is gone, as far I know, but I saved the table with the body measurements:

*This image is copyright of its original author

Now, as you can see, the image of the Russian bear is incorrect, as I escalate it like if the bears were measured in straight line, when actually they were certainly taken along the curves. In this case, I made a new image in 2020, with other corrections like the body mass in modern records and I also re-escalated the Amur tiger size in the image. Check it:

*This image is copyright of its original author

Please, check the difference in the escalation, the size is closer to the size of the Grizzly now, which make more sense. About the body mass, I just found pieces of the modern records so I tried to reconstruct the information, however @peter made a good compilation of the especific modern records and the heaviest male was of 363 kg, here are his tables:

*This image is copyright of its original author

*This image is copyright of its original author

Taking the 8 males from this list and the other 2 males captured in 2011 and reported in the document of 2014, the average weight for the male Russian bears in the Sikhote Alina area, in modern records, is of 247.5 kg.

Certainly I need to update the images, and add the figures presente by peter.

Hope this helps. Reply