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: Madison River, Yellowstone National Park, Wyoming
Image ID: 19700
Bull elk in sage brush with large rack of antlers during the fall rut (mating season). This bull elk has sparred with other bulls to establish his harem of females with which he hopes to mate.
Species: Elk, Cervus canadensis
Location: Mammoth Hot Springs, Yellowstone National Park, Wyoming
Image ID: 19718
Sea otters mating. The male holds the female's head or nose with his jaws during copulation. Visible scars are often present on females from this behavior. Sea otters have a polygynous mating system. Many males actively defend territories and will mate with females that inhabit their territory or seek out females in estrus if no territory is established. Males and females typically bond for the duration of estrus, or about 3 days.
Species: Sea otter, Enhydra lutris
Location: Elkhorn Slough National Estuarine Research Reserve, Moss Landing, California
Image ID: 21606
Garibaldi maintains a patch of orange algae (just in front of the fish) to entice a female to lay a clutch of eggs, Farnsworth Banks, Catalina Island.
Species: Garibaldi, Hypsypops rubicundus
Location: Catalina Island, California
Image ID: 37255
Male elephant seals (bulls) rear up on their foreflippers and fight for territory and harems of females. Bull elephant seals will haul out and fight from December through March, nearly fasting the entire time as they maintain their territory and harem. They bite and tear at each other on the neck and shoulders, drawing blood and creating scars on the tough hides. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 15394
A bull elephant seal forceably mates (copulates) with a much smaller female, often biting her into submission and using his weight to keep her from fleeing. Males may up to 5000 lbs, triple the size of females. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 35133
Adult male humpback whale singing, suspended motionless underwater. Only male humpbacks have been observed singing. All humpbacks in the North Pacific sing the same whale song each year, and the song changes slightly from one year to the next.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 02802
Humpback whale competitive group, several adult male escort whales swimming closely together as part of a larger competitive group.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 02864
Humpback whale competitive group, several adult male escort whales swimming closely together as part of a larger competitive group.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 02862
Brown bear female sow with spring cubs. These three cubs were born earlier in the spring and will remain with their mother for almost two years, relying on her completely for their survival.
Species: Brown bear, Ursus arctos
Location: Lake Clark National Park, Alaska
Image ID: 19181
A bull elephant seal forceably mates (copulates) with a much smaller female, often biting her into submission and using his weight to keep her from fleeing. Males may up to 5000 lbs, triple the size of females. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 20388
A bull elephant seal forceably mates (copulates) with a much smaller female, often biting her into submission and using his weight to keep her from fleeing. Males may up to 5000 lbs, triple the size of females. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 35132
Male elephant seals (bulls) rear up on their foreflippers and fight for territory and harems of females. Bull elephant seals will haul out and fight from December through March, nearly fasting the entire time as they maintain their territory and harem. They bite and tear at each other on the neck and shoulders, drawing blood and creating scars on the tough hides. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 35135
Male elephant seals (bulls) rear up on their foreflippers and fight for territory and harems of females. Bull elephant seals will haul out and fight from December through March, nearly fasting the entire time as they maintain their territory and harem. They bite and tear at each other on the neck and shoulders, drawing blood and creating scars on the tough hides. Sandy beach rookery, winter, Central California.
Species: Elephant seal, Mirounga angustirostris
Location: Piedras Blancas, San Simeon, California
Image ID: 35150