The Elk Rut
Male elk bugling during rut season.
Photos and story by Rachel Ames, EVWC Board Member
Now that the days are growing shorter and a chill is in the air, it is one of the most special times in the Estes Valley. The elk rut! I often think of this time as what a zoo would be like if they opened all the animal pens. At the Estes zoo, hormone-influenced elk run around town without regard to golf games or intersections, and humans get “elk fever” which induces a burning desire to get up close and personal with the elk while suffering a simultaneous loss of common sense. The fact that we all get a front-row seat to the action makes it special.
Why is the rut so important? It is a time when both males and females reunite, mix and mingle after being apart for most of the year. It is also a time when adult elk find a mate so that they can create the next generation. Since the female does much of the choosing, competition between males is fierce. What starts out as “friendly” sparring in late summer becomes full-on battle by fall. Of course, the cow elk is just looking for the strongest, and most genetically-gifted male she can find. Because finding the perfect DNA is hard without a microscope, a cow elk has to rely on proxies. In the elk world, a proxy for strength and stamina is the bull elk’s ability to fend off rivals. A bull elk may burn off 20% of his top summer weight while defending his harem during the rut. For a bull to be able to manage this incredible feat, he must be strong and healthy. Another proxy is his bugle. While it sounds high-pitched and squeaky to us, a bull’s bugle changes as he ages. An older male will have a bugle that is irresistible to a cow. After all, an older male has survived the elements for years and thus must be smart and healthy.
Getting to her desired mate isn’t easy, though, and sometimes the cow elk has trouble escaping one bull’s harem to go to another. No matter who she’s with, the cow elk puts up with the testosterone-filled bull until the day, yes day, that she is receptive (in estrus). If he’s been able to fend off his rivals up until that day arrives, the dominant bull of the herd gets the honors of mating with her. Mating isn’t quite as easy as it sounds, though. On one day last September, my husband and I joined several hundred other visitors to RMNP’s Moraine Park to watch the rut. On this morning, there were 5-6 bulls frantically defending their harems between the road and the campground. The atmosphere was especially intense due to the number of bulls, the small area, parked cars and numerous spectators. I had my long lens with me that day, so I walked back a bit and focused on a pair who were mating during the mayhem. I was amazed at how all the other bulls let them be. This bull must have already staked his claim as top bull and the other bulls honored the proverbial tie hanging on the doorknob.
When a bull elk is in his “rut” prime, he has a 40-pound set of antlers on his head and a testosterone-fueled neck and body that don’t make it “easy” to mount a female. On this day, his first attempt was cut short because she was higher up on a slope and he couldn’t get positioned correctly. It was amazing to see how winded he got from the attempt. No worries, though, and soon he was trying again. Except that this time there was another cow nearby and she seemed to be giving them pointers. What does it take to get a little privacy? As he rested for a few minutes, the cow came over to him and mounted the bull! (see above) Yes, you read that right. The cow got on her hind legs and lovingly stroked his back as she mounted him! How’s that for encouragement?
A short while later, he tried again but this time she wasn’t in a good spot and she walked off. After taking a short break, the cow mounted the bull again. The fourth and final time that the bull mounted the cow (see below), it seemed like everything worked correctly and when they were done, they went their separate ways and panted with exhaustion for a few minutes. While they did groom each other a bit afterwards, it was obvious that there were several other cows that were waiting for their turn, too.
What I learned later is that a bull elk in his prime can only really mate with a limited number of cows each season. Between defending his herd and the effort required, after a while he becomes too exhausted. So, if the cow doesn’t take on her estrus mating with the strongest bull, she’ll come back into estrus about 3 weeks later. By this time, a younger bull might be the one defending the herd. In this way, the younger bull might get a chance to propagate his genes. This is what I love about the way elk breed. The process gives the best chance to the strongest (and typically older) males, but there is also a mechanism for getting young DNA into the herd.
So, the next time you watch the elk rut, remember what it is all about and appreciate the beauty of the mate-finding and mating process, as well as all the theatrics that go into this frenzied time of year. Just be sure to give them a little space!
