A bull musk ox in the Arctic National Wildlife Refuge. Both male and female musk oxen have horns, although the male’s horns are thicker. Both sexes use their horns to fend off predators and in contests of dominance, slamming together headfirst after a top-speed dash of 50 yards or more.
Steller sea lions off North Marble Island, in Glacier Bay National Park and Preserve. The Steller sea lion is much larger and lighter in color than the California sea lion. Although they don’t migrate, sea lions do shift their central haulouts to track seasonal concentrations of food
A male walrus near Cape Peirce in the Togiak National Wildlife Refuge. Both male and female walruses have tusks, which they use to forage shellfish from the ocean floor, create breathing holes in ice, and even haul their heavy bodies out of the water. Males also use their tusks to battle each other during breeding season, sometimes inflicting serious wounds.