Next to the beaver, the porcupine is the largest rodent in the United States; the largest porcupines live in Alaska. When on the ground, his short, thick tail drags in the snow, leaving a zigzag trail. When the snow is deep and the weather stormy, he spends much of his time in pine, spruce, and hemlock trees, feeding on the bark and twigs. [Illustration: NORTHERN SHRIKE.] Notes January Thirty-first Hawks, before eating, tear away the skin and feathers from their prey; but owls eat everything, unless the prey be large, even bolting small birds and mammals entire. In the course of a few hours they disgorge pellets of indigestible portions, the bones being encased in the feathers or hair. The pellets may be found on the snow beneath the owl's roost, and they often contain skulls of mice as white and perfect as though they had been cleaned in a museum. Notes =February= February First Mourning-cloak butterflies do not all die when winter comes. Those that hibernate are usually found singly or in clusters, hanging from the rafters in old buildings, or from the under side of stones, rails, limbs of trees, or boards. Those that appear in the spring with tattered wings, have probably been confined in buildings, and in their efforts to escape have battered themselves against the windows. February Second Does any one know how old the story is that tells us this is the day on which the bear and the woodchuck rub their sleepy eyes and leave their winter quarters for the first time? If they see their shadow they return and sleep six weeks longer, but should the day be cloudy, they are supposed to remain active the rest of the season. This of course is only a myth. February Third Frogs usually pass the winter in the mud at the bottom of a stream, lake, or pond, or below frost-line in a woodchuck, rabbit, or chipmunk burrow. However, it is not uncommon to find them active all winter in a spring, or a roadside drinking-trough supplied from a spring. I wonder if they know that spring-water seldom freezes, and that by choosing such a place, they will not have to hibernate. Notes February Fourth The bloodthirsty weasel, which is reddish brown in summer (save the tip of his tail, which is always black), is now colored to match his surroundings, white. His tracks may be found in the woods and along the stump fences in the fields, where he has been searching for mice. He is one of the very few mammals that will shed blood simply for the pleasure of killing. February Fifth