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
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
Brown bear female sow in sedge meadow, with her three spring cubs hidden by the deep grass next to her. These 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: 19154
Sunset light on Half Dome and Clouds Rest, Tenaya Canyon at lower left, Yosemite National Park.
Location: Yosemite National Park, California
Image ID: 36391
Panorama dimensions: 5300 x 19120
Two giant black sea bass swim in a courtship circle, part of a larger gathering of a mating aggregation amid kelp forest, Catalina Island. In summer months, black seabass gather in kelp forests in California to form mating aggregations. Courtship behaviors include circling of pairs of giant sea bass, production of booming sounds by presumed males, and nudging of females by males in what is though to be an effort to encourage spawning.
Species: Giant black sea bass, Stereolepis gigas
Location: Catalina Island, California
Image ID: 33357
Browning Pass aerial photo, with Nigei Island (left) and Balackava Island (right).
Location: British Columbia, Canada
Image ID: 35330
A Panorama of Wildflowers blooms across Carrizo Plains National Monument, during the 2017 Superbloom.
Location: Carrizo Plain National Monument, California
Image ID: 33228
Panorama dimensions: 3798 x 15587
Gray whale, on southern migration to calving lagoons in Baja.
Location: San Diego, California
Image ID: 34230
Photographer in the Virgin River Narrows, with flowing water, autumn cottonwood trees and towering red sandstone cliffs.
Location: Virgin River Narrows, Zion National Park, Utah
Image ID: 26106
SCUBA Diver and Steller Sea Lions Underwater, underwater photographer, Hornby Island, British Columbia, Canada.
Species: Steller sea lion, Eumetopias jubatus
Image ID: 36130
Brown pelican, winter adult breeding plumage, showing bright red gular pouch and dark brown hindneck plumage of breeding adults. This large seabird has a wingspan over 7 feet wide. The California race of the brown pelican holds endangered species status, due largely to predation in the early 1900s and to decades of poor reproduction caused by DDT poisoning.
Species: Brown Pelican, Pelecanus occidentalis, Pelecanus occidentalis californicus
Location: La Jolla, California
Image ID: 23626
Black's Beach sea cliffs, sunset, looking north from Scripps Pier with Torrey Pines State Reserve in the distance.
Location: La Jolla, California
Image ID: 29165