Satellite bulls sparring during elk rut season,
Moraine Park, Rocky Mountain National Park, September 1, 2009
Our 2009 visit to Rocky Mountain National Park was specifically timed to coincide with the annual elk rut season. It was the second time we had been there when the elk herds were gathering in Moraine Park. The previous time was near the end of a four week vacation when we stayed at the Stanley Hotel in Estes Park.
The elk rut takes place between the middle of August and the middle of October, depending on the climate in which they live. During the rut elk frequently use areas around fresh water, and tend to bed in heavy timber five to six hours per day.
Younger, smaller bulls are known as satellite bulls, as they tend to cling to the edges of a herd trying to pick up any cows willing to leave the herd.
Satellite bulls frequently spar with one another during the rut, and in turn make sparring squeaks. A bugle is a vocalization made exclusively by bulls. A bugle can be directed toward other bulls or toward cows. A bull will direct his bugle toward his cows while gathering them or while chasing an estrus cow. A herd bull will direct his bugle toward another bull to express his dominance over the herd, while a satellite bull may use his bugle to challenge the herd bull. (Wikipedia)