Neil Lucas / Two walrus facing one another. {Odonbenus rosmarus} Round Island, Alaska

Mike Potts / Large colony of Walrus {Odobenus rosmarus} beached at Round Island, Alaska.

Staffan Widstrand / Portrait of Walrus {Odobenus rosmaris} asleep on shore, Chukotka, Russia.

Matthias Breiter / Pacific Walrus (Odobenus rosmarus divergens) male portrait, Round Island, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group, Round Island colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) portrait in large colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) at rest in colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony, Siberia, Russia

Steven Kazlowski / Walrus (Odobenus rosmarus) a cow fights off a bull's advances at the end of mating season, Bering Sea, off the coast of Alaska, USA

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull spraying water through nostrils to filter collected food, Round Island, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull swimming in aggressive posture, Round Island, Bristol Bay, Alaska

Eric Baccega / Colony of Pacific walruses (Odobenus rosmarus) Round island, Alaska, North America

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group in water, Alaska

Kevin Schafer / Pacific Walrus (Odobenus rosmarus divergens) male in water, Walrus Islands State Game Sanctuary, Alaska

Kevin Schafer / Pacific Walrus (Odobenus rosmarus divergens) males hauled out on beach, Round Island, Alaska

Kevin Schafer / Pacific Walrus (Odobenus rosmarus divergens), Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group hauled out on beach, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) juvenile bull resting, Bristol Bay, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) bull, Bristol Bay, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) bull, Bristol Bay, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) bulls resting, Bristol Bay, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) bulls resting, Bristol Bay, Round Island, Alaska

Ingo Arndt / Pacific Walrus (Odobenus rosmarus divergens) bulls, Bristol Bay, Round Island, Alaska

Ingrid Visser / Pacific Walrus (Odobenus rosmarus divergens) tusk, scrimshaw depicting a walrus on ice, Kamchataka, Bering Sea, Russia

Steven Kazlowski / Walrus (Odobenus rosmarus) herd resting on and swimming around a chunk of pack ice during the spring breakup. Chukchi Sea, off the National Petroleum Reserves, Alaska

Steven Kazlowski / walrus, Odobenus rosmarus, herds resting on and swimming around chunks of pack ice during spring breakup, Chukchi Sea, off the National Petroleum Reserves, Alaska

Steven Kazlowski / Walrus (Odobenus rosmarus) herd resting on and swimming around a chunk of pack ice during the spring breakup. Chukchi Sea, off the National Petroleum Reserves, Alaska

Steven Kazlowski / Walrus (Odobenus rosmarus) herd resting on and swimming around chunks of pack ice during the spring breakup. Chukchi Sea, off the National Petroleum Reserves, Alaska

Matthias Breiter / Pacific Walrus (Odobenus rosmarus divergens) bulls silhouetted against setting sun, Round Island, Alaska

Neil Lucas / Pacific Walruses lying on rocks in water {Odonbenus rosmarus} Round Island, Alaska

Pete Oxford / Dead Pacific walrus {Odobenus rosmarus divergens} hunted by Upik eskimos, Uelen, Far East Russia 1993

Pete Oxford / Dead Pacific walrus {Odobenus rosmarus divergens} hunted by Upik eskimos, Uelen, Far East Russia 1993

Mike Potts / Aerial view of colony of Male Walrus {Obobenus rosmarus} at haul out on Round Island, Alaska, USA, 1988

Neil Lucas / Walrus hauled out {Odonbenus rosmarus} Round Island, Alaska

Pete Oxford / Yupik eskimos with hunted Pacific walrus, Uelen, E Siberia, Russia

Pete Oxford / Yupik eskimos with hunted Pacific walrus, Uelen, Siberia, Russia

Pete Oxford / Yupik eskimos butchering Pacific walrus, Uelen, Siberia, Russia

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) harvested by Inuits, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull with pale skin hauling-out after many hours in cold sea, after warming on land skin turns reddish-brown, summer, Round Island, Bering Sea, Bristol Bay...

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull with pale skin hauling-out after many hours in cold sea, after warming on land skin turns reddish-brown, summer, Round Island, Bering Sea, Bristol Bay...

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bulls resting in haul-out showing small claws on hind-flipper, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) males with large tusks resting on coastal rocks, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bulls hauled-out in cove protected by rocky outcrop, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) two bulls fighting in shallow waters off-shore, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait on coastal rocks in haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull portrait, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bulls interacting in crowded haul-out cove, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull resting in haul-out cove and waving front flippers, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Yva Momatiuk & John Eastcott / Pacific Walrus (Odobenus rosmarus divergens) bull dozing in haul-out cove, covering head with front flipper, summer, Round Island, Bering Sea, Bristol Bay, Alaska

Matthias Breiter / Pacific Walrus (Odobenus rosmarus divergens) overlooking sea, Pacific Walrus Islands State Game Sanctuary, Alaska

Matthias Breiter / Pacific Walrus (Odobenus rosmarus divergens) group of bulls on beach, Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group, Round Island colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group, Round Island colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group, Round Island colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group, Round Island colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) group silhouetted on offshore rocks, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony, Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony, Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony gathered on shoreline at base of cliff, Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony, Round Island, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) male among colony, Alaska

Michio Hoshino / Pacific Walrus (Odobenus rosmarus divergens) colony with males competing for territory, Siberia, Russia

Eric Baccega / Two Walrus in sea {Odobenus rosmarus} Round Is, Alaska, USA

Eric Baccega / Walruses hauled out on rock {Odobenus rosmarus} Round Is, Alaska, USA

Eric Baccega / Walrus portrait {Odobenus rosmarus} Round Is, Alaska, USA

Eric Baccega / Two Walrus {Odobenus rosmarus} fighting, Round Is, Alaska, USA

Eric Baccega / Walrus hauled out on rock {Odobenus rosmarus} Round Is, Alaska, USA

Eric Baccega / Walruses hauled out on rock {Odobenus rosmarus} Round Is, Alaska, USA

Eric Baccega / Walrus splashing into sea {Odobenus rosmarus} Round Is, Alaska, USA

Pete Oxford / Pacific walrus {Odobenus rosmarus} hunted by Yupik eskimos for food, Uelen, Russia

Eric Baccega / Walrus portrait {Odobenus rosmarus} Round Is, Alaska, USA

Neil Lucas / Walrus group hauled out on shore {Odonbenus rosmarus} Round Island, Alaska