Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing with own air bubbles in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Andy Rouse / Polar bear (Ursus maritimus) mother and yearling cub on pack ice at sunset, Svalbard, Norway. August.

Klein & Hubert / Dun foal jumping over a palomino yearling while playing. Nevada, USA.

Carol Walker / Mustang / wild horses, two yearling cremello colts Claro and Cremesso playing with a bay, McCullough Peak herd, Wyoming, USA, June 2008

Carol Walker / Mustang / wild horse, cremello colt foal Cremesso interacting with yearling filly, McCullough Peak herd, Wyoming, USA, August 2007

Carol Walker / Mustang / wild horse, yearling cremello colt Claro in thick winter coat, stretching, McCullough Peak herd, Wyoming, USA, February 2008

Gerrit Vyn / Dall sheep (Ovis dalli) yearling lamb running across alpine tundra, Denali National Park, Alaska, USA

Wild Wonders of Europe / D'Amicis / Female European brown bear (Ursus arctos) with two yearling cubs walking down steep slope, Western Tatras, Carpathian Mountains, Slovakia, June 2009

Wild Wonders of Europe / D'Amicis / Female European brown bear (Ursus arctos) with two yearling cubs feeding amongst Dwarf pines (Pinus mugo) Western Tatras, Carpathian Mountains, Slovakia, June 2009

Wild Wonders of Europe / D'Amicis / Female European brown bear (Ursus arctos) with two yearling cubs emerging from Dwarf pines (Pinus mugo) Western Tatras, Carpathian Mountains, Slovakia, June 2009

Wild Wonders of Europe / D'Amicis / Female European brown bear (Ursus arctos) with two yearling cubs walking on snow field on mountain ridge, Western Tatras, Carpathian Mountains, Slovakia, June 2009

Carol Walker / Wild Horses / Mustangs, pinto foal and pinto yearling in winter, McCullough Peaks Herd Area, Cody, Wyoming, USA

Doug Perrine / Humpback whale + yearling calf (in foreground) Tonga, Pacific {Megaptera novaeangliae}

Suzi Eszterhas / Polar Bear (Ursus maritimus) lone yearling on shore, Churchill, Manitoba, Canada

Cyril Ruoso / Giant Panda (Ailuropoda melanoleuca) year old cub in a tree, Chengdu Panda Breeding and Research Center, Sichuan, China

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) adult female nursing her two yearling cubs on sedge flats, Katmai National Park, Alaska

Matthias Breiter / Polar Bear (Ursus maritimus) mother with cub in snow, Churchill, Manitoba, Canada

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) yearling cub in temperate rainforest, Tongass National Forest, Alaska

Matthias Breiter / Polar Bear (Ursus maritimus) yearling cub, Hudson Bay, Manitoba, Canada

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) yearling cubs playing in temperate rainforest, Tongass National Forest, Alaska

Matthias Breiter / Polar Bear (Ursus maritimus) yearling cub running, Hudson Bay, Manitoba, Canada

Anup Shah / African Lion (Panthera leo) yearling cub playing with younger cub, biting its tail, Masai Mara, Kenya

Anup Shah / African Lion (Panthera leo) yearling cub playing with younger cub, Masai Mara, Kenya

Donald M. Jones / Black Bear (Ursus americanus) yearling cub at base of spruce tree, Alberta, Canada

Donald M. Jones / Black Bear (Ursus americanus) yearling cub up in a Lodgepole Pine (Larix laricina), Alberta, Canada

Matthias Breiter / Grizzly Bear (Ursus arctos horribilis) female with yearling cub, Katmai National Park, Alaska

Yva Momatiuk & John Eastcott / Mustang (Equus caballus) palomino yearling filly and her spring foal brother grooming each other, Pryor Mountain Wild Horse Range, Montana

Thomas Mangelsen / Polar Bear (Ursus maritimus) mother and two yearling cubs sitting on ice field, Churchill, Manitoba, Canada

Mark Raycroft / Black Bear (Ursus americanus) sow with yearling cub

Jim Brandenburg / Timber Wolf (Canis lupus) alpha female resting as yearling growls at camera, Minnesota

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) juvenile blowing bubbles, Floreana Island, Galapagos, South America, Pacific Ocean.

Tui De Roy / Juvenile Galapagos sea lion (Zalophus wollebaeki) hunting Black-striped Salemas (Xenocys jessiae). Rabida Island, Galapagos, Ecuador.

Tui De Roy / Juvenile Galapagos sea lion (Zalophus wollebaeki) hunting Black-striped Salemas (Xenocys jessiae). Rabida Island, Galapagos, Ecuador.

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing withg own air bubbles in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing withg own air bubbles in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing withg own air bubbles in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pups playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pups playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in shallows, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup chasing anchovy shcool, Puerto Egas, Santiago Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing with stick, Santa Fe Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playfully clambering on mother's back, Mosquera Islet, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in shallows, Rabida Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in sea cave, Gardner Islet, Espanola Island, Galapagos, Ecuador

Tui De Roy / Galapagos sea lion (Zalophus wollebaeki) yearling pup playing in sea cave, Gardner Islet, Espanola Island, Galapagos, Ecuador