Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram flehming, Waterton Canyon, Colorado

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) sub-adult ram, Waterton Canyon, Colorado

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) sub-adult ram, Waterton Canyon, Colorado

Dawn Y. Wilson / Elk (Cervus elaphus) bull bugling in winter, Rocky Mountain National Park, Colorado

Dawn Y. Wilson / Elk (Cervus elaphus) bull in defensive posture in winter, Rocky Mountain National Park, Colorado

Marie Read / Wilson's Phalaropes (Phalaropus tricolor), flock flying over tufa formations at Mono Lake, just after sunrise, California, USA.

Dawn Y. Wilson / Elk (Cervus elaphus) sub-adult bull, Rocky Mountain National Park, Colorado

Dawn Y. Wilson / Grizzly Bear (Ursus arctos horribilis) pair play-fighting, Lake Clark National Park and Preserve, Alaska

Dawn Y. Wilson / Grizzly Bear (Ursus arctos horribilis) pair play-fighting, Lake Clark National Park and Preserve, Alaska

Dawn Y. Wilson / Grizzly Bear (Ursus arctos horribilis) cub playing with shell, Lake Clark National Park and Preserve, Alaska

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram with bloody nose from fighting, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram flehming, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram displaying dominance, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams chasing each other during fall rut, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram feeding on grass, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram showing dominance display, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram scent-marking, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram scent-marking, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting during rut, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting during rut, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting during rut, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams fighting during rut, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram displaying dominance, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram standing about to fight, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram in winter, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) rams and female, Shoshone Canyon, Wyoming

Dawn Y. Wilson / Bighorn Sheep (Ovis canadensis) ram flehming, Shoshone Canyon, Wyoming