"Overhunting" vs. "undermanagement" feels like a distinction without a difference outside a small circle of purely scientific inquiry.
The situation with bison in the US was deeply unnatural when you think about it. Bison are large herbivores, that can reproduce fairly quickly, and that don't have any consistent predators.
Nothing in the US can hunt them successfully and consistently. A wolf pack can take down a grown bison, but it's risky for them, and the wolf population was nowhere large enough to control the bison population numbers. Cougars and coyotes can prey on calves, but not on healthy grown bison.
Just guessing, but I would think there would have been a lot of cougars eating a lot of calves. That would also have some restraining impact on the population.
Only if you include Native Americans in the "natural" forces. They were responsible for the disappearance of the local megafauna.
> At the very least food availability would have limited their numbers in some way.
Or maybe periodic population collapses due to disease.
> It isn't dissimilar to the situation with bears.
Grizzly bears have one of the slowest reproduction rates, though. They simply won't have cubs if there isn't enough food. In Africa, it's a similar story with elephants, nothing can hunt them consistently, but they reproduce so slowly that they can't really overpopulate the area.
For Plains indigenous people, the buffalo were a massive part of their culture, spirituality and history. Hundreds of generations had lived alongside the buffalo herds and become a part of their life cycle. Their hunts, while truly massive, participated in the life cycle and ensured stable herds.
When european settlers came, they had absolutely no understanding of that life cycle so their hunts were in opposition. Then as they started importing european land ownership and putting up fences, the ecosystem collapsed. They hadn’t followed the herds for generations so really didn’t know how much land a herd actually needed to sustain itself.
It was really the wrong hunting even more so than over hunting. Early communities had names like “Pile of Bones” that were indicative of the scale of earlier hunts.