Porcupine, Porcupines, Erethizon dorsatum, fauna, herbivore, herbivorous, herbivores, Mammal, Mammals, Rodent, Rodents, North American wildlife, wildlife, Forest, Forests, Woodland, Woodlands, Boreal Forest, North America, Rocky Mountains, Kitchin, Hurst, quill, quills, Porcupine Quills, Jasper National Park, Canada, Alberta, defense, defence, defensive posture, Vertical