To start this mission, talk to Pearson who will tell you about the gang’s food woes. Charles will be accompanying you on this hunting trip as well. This will be a tutorial mission for hunting so make sure to take note of the basics. Once you’re on horseback, simply follow Charles.
Continue until Charles spots some tracks. Get off from your horse then draw the bow from your horse. Equip it from your weapon wheel then crouch down. Use your Eagle Eye to find the track and press R1 to track it. Eagle Eye is a very useful not only for hunting but also for highlighting objects of interest inside buildings and houses. Use this ability as often as needed to help you out while hunting and scavenging. For now, follow the tracks while remaining crouched.
Keep following the tracks until you finally see the deer by the stream. Don’t get too close; just aim for the neck or head, fully draw your bow, then release it. Drawing the bow at full will increase the damage and range of your arrow. If you draw too long, the strain will cause Arthur’s stamina to drain and his aim will start to wobble. If this happens, don’t release your arrow to avoid spooking the animal and replenish your stamina as needed. You’ll have to reset your aim and try again. For this mission, even hitting the body of the deer at full draw will cause a fatal hit.
Approach the deer to recover your arrows then use your Eagle Eye again to track another deer. Cross the stream and you should see another deer nearby. After killing it, approach the carcass of the second deer and pick it up. You have to load the carcass on the back of your horse. If your horse is nearby, just whistle to it to call it to your position. The higher your bond with your horse, the farther it can respond to your calls.
The deer will be added to your compendium as well. Your compendium will be updated whenever you study, tracked, killed, or skinned an animal. Some animals like horses, dogs, and cats don’t need to be killed but only need to be studied to be added to your compendium. If you’re a completionist, you’ll have to invest a whole lot of time cataloging all entries.
After loading the deer carcass, ride back with Charles to the camp. Upon arriving, pick up the carcass and drop it on the floor in Pearson’s kitchen. There, you’ll be able to skin the carcass. Skinning (or plucking for birds) allows you to collect various animal parts, primarily meat for cooking and pelts for selling/crafting. Other animal parts can be sold for cash or used as crafting materials. It’s recommended to do this action when hunting. Mission complete.