So, I know ecological niches can only be fulfilled by a single creature. If two creatures compete, one will either go extinct or be displaced. But I was thinking, don't wolves and certain extinct felines native to cold regions where wolves are share an ecological niche (large animals like mammoths, bovids, etc.). And prior to their extinction, wouldn't neanderthals have shared a niche with these creatures as well? And don't bears, cougars, and wolves all co-exist in the American west? Or is there more to it than the food source?

  Essentially, how can various large carnivores that seem to feed off the same things co-exist in some regions?

sorry no-one seems to know the answer to your question.