Bull elk, with large antlers, alongside female elk during rutting season, autumn. A bull will defend his harem of 20 cows or more from competing bulls and predators. Only mature bulls have large harems and breeding success peaks at about eight years of age. Bulls between two to four years and over 11 years of age rarely have harems, and spend most of the rut on the periphery of larger harems. Young and old bulls that do acquire a harem hold it later in the breeding season than do bulls in their prime. A bull with a harem rarely feeds and he may lose up to 20 percent of his body weight while he is guarding the harem.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19696
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: 19705
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: 19711
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: 19726
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: Yellowstone National Park, Wyoming
Image ID: 19729
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: Yellowstone National Park, Wyoming
Image ID: 19731
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: 19735
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: 19736
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: Yellowstone National Park, Wyoming
Image ID: 19737
Elk, bull elk, adult male elk with large set of antlers. By September, this bull elk's antlers have reached their full size and the velvet has fallen off. This bull elk has sparred with other bulls for access to herds of females in estrous and ready to mate.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19739
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: 19744
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: 19745
Elk, bull elk, adult male elk with large set of antlers. By September, this bull elk's antlers have reached their full size and the velvet has fallen off. This bull elk has sparred with other bulls for access to herds of females in estrous and ready to mate.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19747
Large male elk (bull) in snow covered meadow near Madison River. Only male elk have antlers, which start growing in the spring and are shed each winter. The largest antlers may be 4 feet long and weigh up to 40 pounds. Antlers are made of bone which can grow up to one inch per day. While growing, the antlers are covered with and protected by a soft layer of highly vascularised skin known as velvet. The velvet is shed in the summer when the antlers have fully developed. Bull elk may have six or more tines on each antler, however the number of tines has little to do with the age or maturity of a particular animal.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19749
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: 19750
Large male elk (bull) in snow covered meadow near Madison River. Only male elk have antlers, which start growing in the spring and are shed each winter. The largest antlers may be 4 feet long and weigh up to 40 pounds. Antlers are made of bone which can grow up to one inch per day. While growing, the antlers are covered with and protected by a soft layer of highly vascularised skin known as velvet. The velvet is shed in the summer when the antlers have fully developed. Bull elk may have six or more tines on each antler, however the number of tines has little to do with the age or maturity of a particular animal.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19767
Elk, bull elk, adult male elk with large set of antlers. By September, this bull elk's antlers have reached their full size and the velvet has fallen off. This bull elk has sparred with other bulls for access to herds of females in estrous and ready to mate.
Species: Elk, Cervus canadensis
Location: Yellowstone National Park, Wyoming
Image ID: 19773
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: 19779
White Dome Geyser, rises to a height of 30 feet or more, and typically erupts with an interval of 15 to 30 minutes. It is located along Firehole Lake Drive.
Location: Lower Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26938
Old Faithful geyser, sunrise. Reaching up to 185' in height and lasting up to 5 minutes, Old Faithful geyser is the most famous geyser in the world and the first geyser in Yellowstone to be named.
Location: Upper Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26940
Steam rises at sunrise in Norris Geyser Basin. Located at the intersection of three tectonic faults, Norris Geyser Basin is the hottest and most active geothermal area in Yellowstone National Park.
Location: Norris Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26943
Steam rises at sunrise in Norris Geyser Basin. Located at the intersection of three tectonic faults, Norris Geyser Basin is the hottest and most active geothermal area in Yellowstone National Park.
Location: Norris Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26944
Great Fountain geyser. Great Fountain geyser's large vent (16 feet across) sits amid wide sinter terraces that act as reflecting pools as the geyser slows fills prior to its eruption.
Location: Lower Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26948
Steam rises at sunrise in Norris Geyser Basin. Located at the intersection of three tectonic faults, Norris Geyser Basin is the hottest and most active geothermal area in Yellowstone National Park.
Location: Norris Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26951
Steam rises at sunrise in Norris Geyser Basin. Located at the intersection of three tectonic faults, Norris Geyser Basin is the hottest and most active geothermal area in Yellowstone National Park.
Location: Norris Geyser Basin, Yellowstone National Park, Wyoming
Image ID: 26952