Have you ever seen the 3 to 5 inches of fat on a caribou? Caribou fat is what gets many Alaskan natives through the winter. You are correct about rabbits and squirrels. Of course, I could live on my body fat for a while before I need a porupine.Yes. Even in areas where there was no law against it they were reserved for emergency situations by common consent & social pressure.
They are easy to kill and have lots of fat. Fat is important, some nutrients are fat soluble. If all you have to eat is lean meat (eg rabbit, squirrel, caribou) you will quickly succumb to vitamin deficiency.