Once you have spoken with the hunter to begin the hunting challenge, your map will be updated with a small search zone to the north. We need to find and kill 5 beavers. Fortunately, as we realised earlier, beavers are easy to spot and very slow in animal terms. Activate your Eagle vision to locate them and then quickly sprint over and kill them with the hidden blade.
The only thing you need to watch out for in this challenge is that if you stray too far along the beach you can run into a supply camp and the guards here will begin to attack you whilst you are still trying to gather furs. As such, it is best to stick around near the starting area for your beaver destruction.
Once you have the required pelts, the challenge will be complete.