Male elk bugling during the fall rut. Large male elk are known as bulls. Male elk have large antlers which are shed each year. Male elk engage in competitive mating behaviors during the rut, including posturing, antler wrestling and bugling, a loud series of screams which is intended to establish dominance over other males and attract females.
Species: Elk, Cervus canadensis
Location: Mammoth Hot Springs, Yellowstone National Park, Wyoming
Image ID: 19693
A great white shark opens it mouth just before it attacks its prey with a crippling, powerful bite. After the prey has been disabled, the shark will often wait for it to weaken from blood loss before resuming the attack. If the shark looses a tooth in the course of the bite, a replacement just behind it will move forward to take its place.
Species: Great white shark, Carcharodon carcharias
Location: Guadalupe Island (Isla Guadalupe), Baja California, Mexico
Image ID: 19452
Scalloped hammerhead shark swims over a reef in the Galapagos Islands. The hammerheads eyes and other sensor organs are placed far apart on its wide head to give the shark greater ability to sense the location of prey.
Species: Scalloped hammerhead shark, Sphyrna lewini
Location: Wolf Island, Galapagos Islands, Ecuador
Image ID: 16246
A great white shark swims through the clear waters of Isla Guadalupe, far offshore of the Pacific Coast of Mexico's Baja California. Guadalupe Island is host to a concentration of large great white sharks, which visit the island to feed on pinnipeds and use it as a staging area before journeying farther into the Pacific ocean.
Species: Great white shark, Carcharodon carcharias
Location: Guadalupe Island (Isla Guadalupe), Baja California, Mexico
Image ID: 19465
Huge California Sea Lion Male Underwater, a bull, patrolling his breeding harem and territory, Coronado Islands, Mexico. His sagittal crest, the bony bump on his head that distinguishes adult male sea lions, is clearly seen. This particular sea lion bears an orange tag on his left foreflipper, probably as a result of rescue and release as a young sea lion years earlier.
Species: California sea lion, Zalophus californianus
Location: Coronado Islands (Islas Coronado), Baja California, Mexico
Image ID: 38655
Bull elephant seal exits the water to retake his position on the beach. He shows considerable scarring on his chest and proboscis from many winters fighting other males for territory and rights to a harem of females. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 15458
Hammerhead sharks swim in a school underwater at Wolf Island in the Galapagos archipelago. The hammerheads eyes and other sensor organs are placed far apart on its wide head to give the shark greater ability to sense the location of prey.
Species: Scalloped hammerhead shark, Sphyrna lewini
Location: Wolf Island, Galapagos Islands, Ecuador
Image ID: 16271