North American Porcupine

North American porcupines are the continent's second-largest rodent after the beaver — slow, blackish, and as much at home up a tree as on the ground, weighing anywhere from about 11 to 30 pounds. Some 30,000 barbed quills cover the back, sides, and tail, yellowish-white with dark tips, and they're a last resort: a threatened porcupine climbs first, then chatters its teeth and gives off a sharp smell, and only turns its quilled back on whatever keeps coming, with the barbs working each quill deeper once it's in. They feed mostly at night, living largely on the inner bark of trees, mistletoe, and pine needles through the cold months and ground plants in summer, with a craving for salt that draws them to salty tool handles and plywood — and the trees they work over grow stunted, twisted crowns. A single well-developed young, quills and all, arrives in spring after a seven-month gestation.