It is up to you whether to treat these as real species. The texts describe bears, ape-men, and intelligent monkeys with human-level reasoning. That said, we lack both archaeological evidence to prove that any such species ever existed. And it is not feasible Biologically to have Human like Intelligence in Animal like Brain.
However, a more plausible reality is that they were simply forest-dwelling tribesmen who dressed like animals. The tradition of donning animal hides and embodying a creature's spirit is not new—tribes across the globe, particularly in the Americas, have long practiced these rituals to channel the animal's essence.
These Tribes tend to be highly spiritual and Mystical. That is one thing they talked about them mastering Ashta Siddhis. Even Rama and Sita did not possess such Ashta Siddhi.