Gerrit Vyn / Porcupine (Erethizon dorsatum) on tundra. North Slope, Alaska, USA. September.

Steven Kazlowski / North American porcupine (Erethizon dorsatum) pup feeds on Alaskan high brush cranberries in the foothills of the Takshanuk Mountains, South-East Alaska, USA

Rod Williams / North American Porcupine (Erethizon dorsatum). Captive. Endemic to North America. Captive. UK, May.

Claudio Contreras / Balloon fish (Diodon holocanthus) with defensive spines, Puerto Morelos National Park, Caribbean Sea, Mexico, January

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

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

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

LYNN M. STONE / North american porcupine in tree in winter, USA.

Ingo Arndt / Burned trees in front of Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, USA, September 2011.

Ingo Arndt / Grand Prismatic Spring, Midway Geyser Basin, Yellowstone National Park, Wyoming, USA, September 2011.

Solvin Zankl / By-the-wind sailor (Velella velella) colony. Sargasso Sea, Bermuda.

Andy Rouse / Galapagos sea lion (Zalophus wollebaeki) silhouetted at sunset, Galapagos.

Peter Cairns / Twilight over Flakstad beach, Lofoten, Norway. February 2014.

Peter Cairns / Twilight over Flakstad beach, Lofoten, Norway. February 2014.

Ole Jorgen Liodden / Svalbard reindeer (Rangifer tarandus platyrhyncus) feeding at sunset, Spitsbergen, Svalbard, Norway, April.

Tom Gilks / Nyiragongo volcano lava lake, Virungas National Park, Democratic Republic of Congo February 2015.

Steven Kazlowski / Photographer in front of Northern lights / Aurora borealis glowing brightly over the frozen eastern Beaufort Sea, Arctic National Wildlife Refuge, Alaska Model released.

Alex Hyde / Alpine meadow, Nordtirol, Austrian Alps, July 2014.

Christophe Courteau / Light of the Creac'h Lighthouse at night. Ile d'Ouessant / Ushant, Finistere, Brittany, France, September 2011.

Wild Wonders of Europe / Bartocha / Early purple orchid (Orchis mascula) on the Forca Canapine, Monti Sibillini National Park, Italy, May.