Konrad Wothe / Common Porcupine (Erethizon dorsatum), North America

Tim Fitzharris / Common Porcupine (Erethizon dorsatum) portrait, Montana

Gerry Ellis / Common Porcupine (Erethizon dorsatum) climbing tree, North America

Tim Fitzharris / Common Porcupine (Erethizon dorsatum) feeding on fruit, Montana

Matthias Breiter / Common Porcupine (Erethizon dorsatum) in willow tree near the Denali highway, Alaska

Michael Quinton / Common Porcupine (Erethizon dorsatum) feeding on Pussy Willow (Salix discolor) in spring, Alaska

Michael Quinton / Common Porcupine (Erethizon dorsatum) sitting in a tree in winter, Yellowstone National Park, Wyoming

Michael Quinton / Common Porcupine (Erethizon dorsatum) feeding on Pussy Willow (Salix discolor) in spring, Alaska

George Sanker / North American porcupine (Erethizon dorsatum) feeding. Yellowstone National Park, Wyoming, USA. May.

George Sanker / North American porcupine (Erethizon dorsatum) feeding. Yellowstone National Park, Wyoming, USA. May.

George Sanker / North American porcupine (Erethizon dorsatum) feeding on riverbank. Yellowstone National Park, Wyoming, USA. May.

Gabriel Rojo / Brazilian porcupine (Coendou prehensilis) in tree. Cuiaba River, Pantanal, Mato Grosso, Brazil.