Bear Size ~

[Polar]

Evidence for the greater predatory habits of ancient brown bears isn't only located in true anecdotes, but also in physical evidence.

There have been reports of bear-bones, dated two centuries ago, that have a higher concentration of nitrogen: nitrogen-15. N-15 is found in high amounts in carnivores/meat-eating animals, regardless of species.

So it is a proven fact that bears were more carnivorous back then without major human intervention.

But like the situation with Bengal Tigers, how do we really know that brown bears are getting smaller (polar bears sure are)? Bengal tigers in some populations were smaller at the turn of the 20th century, and now they are larger in the same areas. Vice versa in other populations of tigers.

Some brown bear populations have stayed the same size; namely the Rockies, Inland tundra, Kodiak, and Gobi grizzlies. Some populations have grew larger; Alberta, Northwest Pacific, and Scandinavian grizzlies. Some populations grew smaller; the Siberian, Californian, Mexican, and mainland European grizzlies.

Notice that the brown bears that became smaller lived in vast and diverse environments with plenty of prey, not just in number of prey but in the size of prey as well. The ones who grew larger or stayed the same size didn't have the same prey situation or geographical diversity.

Tigers grow largest in marshlands, and lands that have forests, grasslands, and marshes combined; diversity of prey and geography.

Coincidence?

Not at all. Reply