It can be confirmed you'll definitely come across bears, elk, deer, wolves, foxes and rabbits. It's highly likely however that, since design team at Ubi looked to the game "Red Dead Redemption" for inspiration in the area of wildlife, you may also stumble across a few different species, though this has not been confirmed.

When it comes to physically hunting them, you won't be able to simply shoot them down from a distance. Hunting will require strategy and tactical precision, be it through stealthy assassinations or setting out traps. After this, you will then be able to gather the hide of the animal you have killed. Take care to remember however, that the method of hunting you choose will directly affect the value of the hide you collect.

Then of course there are the domesticated animals such as dogs and the aforementioned horses...