Curious Nature: Time for the elk rut
September 16, 2012
Elk (Cervus elaphus) live in a variety of regions in North America and can be found throughout the Rocky Mountains. Their nickname, Wapiti, comes from the Shawnee language and literally means “white rump.” Thus, it is no surprise that elk are easily identified not only by their tan bodies and darker necks, but also by the light patch of fur on their rumps. Similar to other members of the deer family, male elk also possess a pair of antlers that they will shed and regrow every year.
Like most elk that live in mountainous country, the elk here in the Southern Rockies will migrate to higher elevations for the spring and summer and follow the melting snow as it exposes new and fresh vegetation that they can eat. The elk will typically stay up in the alpine tundra for most of the summer because there is enough food for them to eat and because they, like us humans who enjoy living here in Eagle Valley, like to get away from the heat and insects that they would have otherwise had to deal with at lower
During the fall season, elk congregate together to perform their annual mating rituals. Typically, as temperatures get cooler and food becomes scarce, elk will migrate and congregate at lower elevations where there is more food available. Cows (females) will gather in harems, while bulls (males) will compete with one another for the opportunity to mate will these groups of females.
This mating period is known as the elk rut. The term “rut” is originally derived from the Latin word rugitus or rugire, which means “to roar.” Consequently, one major aspect of the elk rut is the bugling of the bull elk, which begins as a crescendo of deep, resonant tones that rise rapidly to a high-pitched squeal before dropping to a series of grunts. This eerie call serves to attract females and intimidate rival males.
The bugle is used to attract females by advertising a bull’s availability to breed. A bull’s bugle advertises not only his presence, but also his health and fitness. While the pitch and length of the bugle varies for each individual bull, the more mature and larger bulls usually bugle more loudly than the younger bulls and as a result, are more effective in attracting females and discouraging potential male competitors.
Bulls will also bugle to announce or accept a challenge from another male. As they bugle at each other, bulls will be sizing each other up. To display their dominance and to try to intimidate each other, bulls will also display their bodies and antlers, paw at the ground, wrestle shrubs and thrash the ground with their antlers, and march side by side. Two bulls may engage in all of these extravagant displays without ever touching each other and the less dominant, less confident bull may retreat. If the confrontation escalates into a physical fight, bulls will lock antlers and push and shove each other in what is a show of strength rather than a battle to the death. Once dominance is established, the victor in the fight will become the master of a harem, having earned the right to mate with that group of cows. However, victory can be temporary. Until the cows come into estrus and are ready to mate, a bull must be constantly defending his harem and discouraging other bulls.
It is no surprise then that the elk rut is a season of constant competition and excitement. So as the aspens begin to peak and the snow starts to fall, keep an ear tuned for the sounds of autumn and the bugles of the elk rut – it is very likely that you might hear it before you see it.
Theresa O’Halloran is a naturalist at Walking Mountains Science Center.