As you say, the water content in a tangerine and animal fat is negligible, ask yourself how much water your body would use to digest these items. Everyone knows, in a survival situation, unless you have a sustainable supply of water, your better off eating nothing as your body uses more water to digest food than there is water in the food. This is why I wouldn't be eating much at first,not without plenty of water. If you can catch big game you can smoke the meat to preserve it, use the hide/fur as clothing and collect the fats for cooking, fires, lamps etc etc. water needs to be a priority over food, as said you can live for 3 weeks without food but only 3 days without water. It also a known fact, in a survival situation, we use more water to digest food than there is actually in the food.....in general.