You can remove the entrails from trout and cook them whole. Other fish should be scaled or filleted if large enough. Carry some tied flies in case you can’t find bait.
Most mammals are edible. Some aren’t too tasty. They say you shouldn’t eat rabbit if you don’t have vegetables. Most places that have rabbits have some form of edible vegetation. Rabbits are vegetarians. Duh!
It’s better to skin animals before removing the entrails. Less hair gets on the meat. Carry plastic bags to put the meat in. If you can get deer sized animals to camp in a reasonable time, skin them and gut them there too. You won’t have to carry heart and liver separately that way either. If you have dogs with you, they can then have lights, kidneys, and diaphram, etc. as well as bones.
When I was a boy, we ate half the deer while we were cutting it up. Eating raw animals or fresh water fish today is probably not a good idea. Besides trichinosis in bears and wild pigs, there are many other parisites that survive as “cysts” in the meat. Not to mention all those newly discovered diseases in wild animals. Rabies can’t survive more than 72 hours outside a living host, but eating obviously diseased animals isn’t something I would recommend, cooked or not. Except in the most barren regions there is just too much other food, if you know where to look.
Besides squirrels, some of the best eating is rodents. Woodchuck is the only one I don’t really care for. Some say that it can be prepared so that it’s not so gamey, but I’ve never found the way. Still it’s better than starving. A porcupine is one of the easiest animals to catch, but be careful. Those barbed quills may be worse than hunger. My favorites are beaver and muskrat, but be careful not to touch the meat with hand or knife if you cut a gland. Wash them first. Glandular secretions make the flesh gamey. You can skin and fry the paddle of a beaver, though it’s mostly bone. The grease splatters badly, so don’t get your face too close to the skillet. The meaty part of the tail makes a good roast, similar to pork. In saurkraut you can’t tell the difference.
You can buy a dozen snares for about a buck apiece and put a couple in your survival gear. Or buy heavyweight braided wire fishing leader. A roll of that is about the size of a pack of cigarettes. It will take most small animals, especially if you watch over it. If you opt for the ready made snares, you will need wire or something to anchor it. Sometimes these little things are all too easy to overlook.
Hope you can make out the deeper water of the channel under the logs with the snare and the body gripping trap. Under logs with these beaver runs or channels is a safe and productive place for beaver. Memorize these places when you see them. If you get snowed in and the ice is thick enough to walk on, you can make a hole in the ice and attach a snare to a large limb or the log. Under the ice you don’t even have to put it under the log. Just under the ice. Be sure it’s in the middle of the channel.
In warmer weather, if your meat becomes tainted, impale it over the water on a long pole. Flies will lay maggots which will fall in the water attracting fish.