ROCKY MOUNTAIN NATIONAL PARK — With autumn fast approaching, one of the iconic signifiers of that seasonal shift is about to take place: the annual elk rut. This dramatic mating ritual is best known by the bulls' wild call that accompanies the act.

This week’s article takes a “behind the scenes” look at the famous elk bugle.

Elk use a wide range of vocalizations to communicate with one another throughout their lives. From mews and barks to “chuckles” and bugles, each sound has a meaning. Scientists and hunters can really only theorize as to the specifics of the calls, but most conclusions are backed up by years of observations.  

The most notable call is the bugle. It is singular to just the bulls. While it can be heard at any time of the year, it is most widely used during the (roughly) six-week rut season, plus a few weeks before and after the season.

The specific reason for the call is unknown. Most of the year it is likely used to communicate location over long distances. As bulls tend to keep to themselves or small bachelor herds when not in rut, they may bugle to locate one another or to delineate territory in the forest or throughout vast mountain valleys.  

The call itself has a distinct tone created by a method known as biphonation. Biphonation is the simultaneous production of two distinct, non-harmonically related fundamental frequencies. It is performed by all kinds of animals, from birds and horses to whales and even humans.  

Throat singing by humans is a perfect example of biphonation. It is performed in various cultures throughout the world, from chanting Tibetan monks to South African tribes. It is best known from the Tuvan nomads of eastern Siberia and neighboring Mongolian tribes and by North American Inuit.

The elk bugle, like throat singing, originates in the larynx and finishes as air is forced over the palate and through the nasal passages. The bugle begins as a low-pitched “growl” and finishes as a nasally “whistle” that can be heard over great distances.  

During the rut, when it is used the most, it is theorized that the call has various meanings. From attracting cows to warning off other bulls from a harem, its intent is differentiated by the specific tones and pitches in each situation. 

Bulls have the ability to pull their larynx deeper into their bodies. The behavior can be seen when a bull straightens and elongates his neck while bugling. This creates a deeper-toned growl—the longer the elongation, the deeper the tone. It is also theorized that the deeper the tone, the more heightened the bull’s aggression.

From observations it has been noted that a warning call to other bulls also tends to have a more aggressive tone during the peak of the whistle. If the call contains more aggressive tones at the end (known as the off-glide) of the whistle, this seems to denote a signal to a cow that may be straying from the harem.  

It should be understood that a bull doesn’t “drive” a harem like a cowboy to his herd. The cows are led by their herd matriarch and they go where they please. The bull is simply working to keep the group together to better protect his “possession” of them from other bulls.

The specific tonal ranges also have nothing to do with a given bull’s maturity. Sometimes a more guttural and “full” bugle comes from a smaller, younger bull while a much larger adult might produce a higher-pitched, “whinier” sound.

Whatever the tone or call might be, the elk bugle is a hauntingly beautiful and sometimes eerie sound. It is a song of nature that sinks deep into one’s soul. To humans, it is an archetypal tribute to the continuation of life in the mating season, and to death in the seasonal shift towards winter and the dying of the light. 

Sources for this article included bit.ly/blognatureorg and bit.ly/nlmnih.

For additional information about James DeWalt Photography, check out jamesdewaltphotography.com.