As a bull elk emerges through through the September morning fog, a primal call pierces the crisp, morning air in Yellowstone National Park. During the mating season, bulls call out to alert females and other males of their presence and physical fitness. The bulls position themselves amid groups of cows and calves where they battle for breeding privileges. Although sexually mature by their second summer, young bulls will rarely have the opportunity to mate until they reach their physical prime, typically between six and eight years of age.
Elk (Cervus canadensis) - Yellowstone National Park, Wyoming