Why didn’t Grizzly bears extend their range into the east say 400 years ago before large scale development? Not enough food on the Great Plains?
I was watching that show on the history channel last night, “After Humans” and they were talking about how fast animal populations can expand given an opportunity. So I’m thinking what kept the Grizzly to the western half of N. America? I am assuming that developed areas keep them locked into the Rockies now.
A quick read of this wiki entry shows that, indeed, their historical range did not include the eastern US. I’m guessing, just from reading this related article that the reason is that that part of the continent was more ideally suited to the black bear.
Following up on Ponder’s post–Grizzlies are better suited to open areas. Black bears are better suited to more heavily forested areas. It looks as though the grizzlies did, at one time, live on the Great Plains as well as the Rockies, but they were never able to successfully exploit the densely forested Eastern US.