• Original Reporting
  • Sources Cited
Original Reporting This article contains new, firsthand information uncovered by its reporter(s). This includes directly interviewing sources and research / analysis of primary source documents.
Sources Cited As a news piece, this article cites verifiable, third-party sources which have all been thoroughly fact-checked and deemed credible by the Newsroom in accordance with the Civil Constitution.

Story by Michael Booth and Photography by Hugh Carey, The Colorado Sun

The annual migration of tourists, photographers and the merely curious to places like Rocky Mountain National Park for the annual elk rut yields images and experiences so engrossing and indelible that we tend to think we know everything about the raw spectacle of large animals using their antlers to establish dominance and then using a bizarre language of grunts and whistles to call attention to their victories. 

But when it comes to Colorado wildlife, there’s always a bit more to learn. We pawed at the ground a bit and unearthed quite a few things we didn’t know: 

A herd of elk in Rocky Mountain National Park.

Mature bulls who have won their battles and formed a harem of cows can keep together up to 20 females for the season. 

People take photos on their phone.

One driver of the brief ungulate sexy show is that cows’ fertility time is extremely short, with the estrus cycle lasting only a day or two, which encourages the bulls to keep their breeding partners close. Young, relatively immature bulls interested in starting a family will be shooed away by the cows, not just angry alpha bulls.

A line of cars in Rocky Mountain National Park.

Once pregnant, the cows carry (usually just one calf) for eight to nine months before reaching term. Elk winter over in the same lower elevation meadows and light forest where we watch mating season, at Moraine Park or Kawuneeche Valley on the west side of Rocky Mountain National Park. Winter and spring visitors can watch the pregnancy-birth cycle in and around Estes Park, or the lower reaches of the national park. 

A bull elk bugles.

The bulls lose weight leading up to the rut as they stress over finding and keeping a harem. But on a normal day, elk each eats up to 20 pounds of vegetation, which is why RMNP has to put fences around the young aspen groves lining the wetland valleys.

A herd of elk in Rocky Mountain National Park.

The urethra of male elk points upward so urine splashes the stomach fur — the musky smell is a cologne, apparently.

A bull elk in Rocky Mountain National Park.

Always remember to stay at least 75 feet away from the big show, for safety and to let nature take its course. And “wapiti” is the safe word.

Two bull elk knock antlers.
Bulls spar with each other. In the fall, male elk tend to be more aggressive to show dominant status and to have mating rights in a group of female.


Michael Booth is a Colorado Sun reporter covering health, health policy and the environment. Email: Twitter: @MBoothDenver