Male Photo

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  

Bull elk spar to establish harems of females, Gibbon Meadow.
Species: Elk, Cervus canadensis
Location: Gibbon Meadows, Yellowstone National Park, Wyoming
Image ID: 13151  

Full grown, mature male coastal brown bear boar (grizzly bear) in sedge grass meadows.
Species: Brown bear, Ursus arctos
Location: Lake Clark National Park, Alaska
Image ID: 19134  

Adams River sockeye salmon. A female sockeye salmon swims upstream in the Adams River to spawn, having traveled hundreds of miles upstream from the ocean.
Species: Sockeye salmon, Oncorhynchus nerka
Location: Adams River, Roderick Haig-Brown Provincial Park, British Columbia, Canada
Image ID: 26161  

Two adult female California Sea Lions, Portrait, La Jolla.
Species: California sea lion, Zalophus californianus
Location: La Jolla, California
Image ID: 36811  

Northern cardinal, male.
Species: Northern cardinal, Cardinalis cardinalis
Location: Amado, Arizona
Image ID: 22891  

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  

Magnificent frigatebird, adult male on nest, with throat pouch inflated, a courtship display to attract females.
Species: Magnificent frigatebird, Fregata magnificens
Location: North Seymour Island, Galapagos Islands, Ecuador
Image ID: 16725  

Steller sea lions (Northern sea lions) gather on rocks. Steller sea lions are the largest members of the Otariid (eared seal) family. Males can weigh up to 2400 lb., females up to 770 lb.
Species: Steller sea lion, Eumetopias jubatus
Location: Chiswell Islands, Kenai Fjords National Park, Alaska
Image ID: 16977  

Magnificent frigatebird, adult female on nest.
Species: Magnificent frigatebird, Fregata magnificens
Location: North Seymour Island, Galapagos Islands, Ecuador
Image ID: 16726  

Black bear walking in a grassy meadow. Black bears can live 25 years or more, and range in color from deepest black to chocolate and cinnamon brown. Adult males typically weigh up to 600 pounds. Adult females weight up to 400 pounds and reach sexual maturity at 3 or 4 years of age. Adults stand about 3' tall at the shoulder.
Species: American black bear, Ursus americanus
Location: Orr, Minnesota
Image ID: 18744  

Sea lions underwater, adult male (left) and female (right).
Species: California sea lion, Zalophus californianus
Location: Sea of Cortez, Baja California, Mexico
Image ID: 31218  

Sea lion harem of females, underwater.
Species: California sea lion, Zalophus californianus
Location: Sea of Cortez, Baja California, Mexico
Image ID: 31228  

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: 02796  

Humpback whale mother, calf (top), male escort (rear), underwater. A young humpback calf typically swims alongside or above its mother, and male escorts will usually travel behind the mother.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 02819  

Adult male humpback whale bubble streaming underwater. The male escort humpback whale seen here is emitting a curtain of bubbles as it swims behind a female (left) during a competitive group. The bubble curtain may be meant as warning or visual obstruction to other male whales interested in the mother.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 02828  

Adult male humpback whale bubble streaming underwater. The male escort humpback whale seen here is emitting a curtain of bubbles as it swims behind a mother and calf. The bubble curtain may be meant as warning or visual obstruction to other nearby male whales interested in the mother.
Species: Humpback whale, Megaptera novaeangliae
Location: Maui, Hawaii
Image ID: 05925  

Pyrrhuloxia, male.
Species: Pyrrhuloxia, Cardinalis sinuatus
Location: Amado, Arizona
Image ID: 22894  

Bullock's oriole, first year male.
Species: Bullock's oriole, Icterus bullockii
Location: Amado, Arizona
Image ID: 22895  

Northern cardinal, female.
Species: Northern cardinal, Cardinalis cardinalis
Location: Amado, Arizona
Image ID: 22897  

Acorn woodpecker, female.
Species: Acorn woodpecker, Melanerpes formicivorus
Location: Madera Canyon Recreation Area, Green Valley, Arizona
Image ID: 22906  

Black-headed grosbeak, male.
Species: Black-headed grosbeak, Pheucticus melanocephalus
Location: Madera Canyon Recreation Area, Green Valley, Arizona
Image ID: 22911  

Brown-headed cowbird, male.
Species: Brown-headed cowbird, Molothrus ater
Location: Amado, Arizona
Image ID: 22916  

House finch, male.
Species: House finch, Carpodacus mexicanus
Location: Amado, Arizona
Image ID: 22927  

Hooded oriole, female.
Species: Hooded oriole, Icterus cucullatus
Location: Amado, Arizona
Image ID: 22944  

House sparrow, breeding male.
Species: House sparrow, Passer domesticus
Location: Amado, Arizona
Image ID: 22945  

Adult female moose in deep meadow grass near Christian Creek.
Species: Moose, Alces alces
Location: Christian Creek, Grand Teton National Park, Wyoming
Image ID: 13039  

The bisons massive head is its most characteristic feature. Its forehead bulges because of its convex-shaped frontal bone. Its shoulder hump, dwindling bowlike to the haunches, is supported by unusually long spinal vertebrae. Over powerful neck and shoulder muscles grows a great shaggy coat of curly brown fur, and over the head, like an immense hood, grows a shock of black hair. Its forequarters are higher and much heavier than its haunches. A mature bull stands about 6 1/2 feet (2 meters) at the shoulder and weighs more than 2,000 pounds (900 kilograms). The bisons horns are short and black. In the male they are thick at the base and taper abruptly to sharp points as they curve outward and upward; the females horns are more slender.
Species: American bison, Bison bison
Location: Yellowstone National Park, Wyoming
Image ID: 13120  

Wood duck, male.
Species: Wood duck, Aix sponsa
Location: Santee Lakes, California
Image ID: 15694  

Black bear walking in a grassy meadow. Black bears can live 25 years or more, and range in color from deepest black to chocolate and cinnamon brown. Adult males typically weigh up to 600 pounds. Adult females weight up to 400 pounds and reach sexual maturity at 3 or 4 years of age. Adults stand about 3' tall at the shoulder.
Species: American black bear, Ursus americanus
Location: Orr, Minnesota
Image ID: 18741