Bull elk over the age of 3 years usually begin bugling shortly after they shed their velvet: from mid-August to early September. Within two to three weeks of shedding their velvet the older bulls begin associating with the cows. During the next few weeks the bulls will try to gather as many cows as they can into a harem, and try to protect them from the advances of other bulls that try to steal them away and breed them. In Minnesota I found that bugling by older bulls starts around August 20th - 24th. Game call manufacturer Larry Jones says he heard his first bugle about August 24th in Idaho in 2002.
The rut (both breeding and bugling) may peak from September 10th to October 10th in different areas, with breeding beginning the first week of September. In Minnesota I found that peak breeding occurs from September 7th to the 21st. While I was guiding in northern New Mexico, I found that peak bugling occurred around September 14th. Well known writer Dwight Schuh tells me peak bugling and breeding occurs from September 20th to the 25th in Idaho. In extreme northern latitudes the rut may occur a week or two later, it may also vary within each state or province. Larry Jones tells me a study done in eastern Oregon showed that peak bugling occurred from September 25th to October 5th. It appears that peak bugling in many areas occurs during the later part of September or early part of October.
The initial breeding phase may last from three weeks before to three weeks after the actual peak of the rut. Information on calving dates for northern elk suggest that breeding will normally last 20 to 45 days. Because spring arrives earlier and fall occurs later in southern latitudes, elk in southern areas may have longer breeding periods; in excess of 50 days for Tule elk in California. Even in northern areas breeding may continue for as long as 65 days, from early September to early November.
When they are in estrus the cows may be sexually receptive for 12 to 15 or more hours. If they are not bred during their first estrus cow may experience estrus again from 21 to 28 days later, with an average of about 21 days. There is usually a second breeding phase three to four weeks after the initial breeding phase, when unbred older cows come into a second estrus. My research suggests that two year old cows my come into estrus one to two weeks after the first of the older cows come into estrus; and that yearling cows may come into estrus two to three weeks after the first of the older cows come into estrus.
There is not much variance in the timing of the elk rut from northern British Columbia to southern New Mexico. If the rut is photoperiodic (dependent on the number of hours of light per day) it would be expected that elk in Montana would rut earlier than those in New Mexico. However this is not necessarily the case. The explanation for this phenomenon is quite simple. Many of the elk of North America are transplants from the Yellowstone ecosystem and still rut when their predecessors did. Because most of these herds are not over a hundred years old they have not had time to readapt to their new environment. There is evidence that Tule elk in California and Rocky Mountain elk in southern New Mexico breed slightly later than their northern relatives, and that their breeding seasons are longer. This is probably because these elk live in areas where fall starts later, which means the calves can be born later and still be big enough to survive the winter.
It has been suggested that peak bugling of elk, like peak gobbling of turkeys and peak scraping of whitetails, occurs prior to and after peak breeding. However, this is not the case. My research shows that peak bugling of elk occurs during peak breeding, when the bulls are trying to attract cows, and when the bulls are competing for breeding rights. One of the ways a bull out-competes other bulls for cows is by bugling. Bulls also bugle frequently when they come in contact with each other as they look for or follow estrus cows. Thus, more bugling occurs when the cows are in estrus, during peak breeding. The Bugling/Bull/5 Minutes graph from my studies shows the average number of bugles per bull per 5 minutes throughout the rut; and shows that peak bugling in 2001 occurred the week of September 14 (during the primary breeding phase) and again on October 5 (during the late breeding phase, which is when subdominant bulls challenge herd bulls for breeding rights). These bugling peaks coincide with peak breeding, but the dates may vary by location.
Once the dominant bulls begin herding they may hold from 1-100 cows, plus calves. While the dominant bull is collecting cows several subdominants and immature bulls may hang around the herd trying to cut out a receptive cow, or breed with one of the cows while the dominant is otherwise occupied chasing cows or bulls, or fighting. Some of these subdominants may be as big as or bigger than the herd bull in body or rack size, but because they have not challenged the dominant and beaten him, they do not have their own herd. Because the dominant bull chases and herds a large number of cows, and breeds several of them, and has to fight off the other bulls, it may eventually succumb to fatigue. When the bull is fatigued it may leave the herd; allow other bulls to stay near the herd and breed cows; or it may be driven off by another bull, which may in turn be driven off by yet another bull. Usually the first bull with a herd will have serviced numerous cows and passed on its genes.
Prior to breeding a cow the bull often sniffs the ground where the cow has been laying, or where it urinated. The bull often performs the lip curl or Flehmen sniff when it checks the urine, it may even stick its tongue in the urine stream while the cow is urinating. If the cow is in estrous it may stand, turn and lick the bulls head, neck, antlers or body; or lift her tail. The cow may also mount the bull. The bull may in turn lick the cow's neck, body or genitals. The bull then leans its neck on the cows back, to see if it will stand still. If the cow is ready to breed it will stand still and the bull will mount the cow. Once mounted the bull usually makes several pelvic thrusts, followed by a jump during ejaculation. During the jump the bull's head is thrown back, and its hind feet often leave the ground. The bull then dismounts and walks away.
Cows may allow more than one bull to mount and breed them. In early October of 2001 I watched a subdominant bull mount a cow while the dominant bull was herding other cows. The subdominant made several pelvic thrusts but did not appear to breed the cow, because it did not jump before it dismounted. The dominant saw the subdominant near the cow and drove the subdominant away. The dominant then followed the cow, and the cow mounted the bull. The dominant bull then mounted the cow several times, and eventually bred the cow. While the dominant was occupied with this cow the subdominant bred one of the other cows.
The roar, bugle and grunt are used by bull elk to proclaim dominance, telling all other bulls in the area, "I am strong, healthy and ready to fight for the right to breed." The Full Bugle Sequence of a dominant bull tells smaller bulls that they should stay away. It tells other large bulls that a dominant is looking for (and probably collecting) cows, and if the other dominant wants to challenge for the right to collect or breed those cows it should respond and be ready to fight, because it will have to take the cows by force. At the same time the bull is telling the cows (many of which may have been in his harem and were bred by the bull last year, and are familiar with the sound and smell of the bull) that he is ready to breed, and where to find him. Because the older cows know the dominant bull by his bugle and scent, and know that he treated them gently the year before, they often go to the same bull again. Younger cows may be intimidated by older bulls, and because they may come into estrus later than older cows, they may choose to associate and breed with smaller subdominant bulls later in the rut.
During the rut bulls may bugle all day and night, but most frequently in the early morning and late afternoon, when the herds are most active and liable to hear the bugling. Therefore, bugling activity closely parallels daily activity, and bugling activity is usually most frequent during feeding periods at dawn and dusk. The bugle serves two purposes, it tells other bulls that there is a dominant in the area and that he is ready to fight for the right to breed. It also serves to let the cows know a breeding bull is near so they can find him. As you can see by the Bugling/Bull/5 Minutes graph, during peak rut a bull averages about two bugles every five minutes. My research shows that older bulls may bugle up to two times per minute, which is probably the most a bull bugle per minute.
Since part of the object of bugling is to advertise the presence of the bull to cows, the bull should want to silence any competition from other bulls. When another bull bugles near a bull with a herd, the herd bull feels a need to meet the challenge and drive the other bull away. At the same time the bull may feel the need to out advertise other bulls by bugling more, in an effort to attract cows. Generally speaking, older bulls with cows bugle more than younger bulls.
Some dominant bulls do very little bugling. Large dominant bulls that drive off all competition can afford to be more leisurely around the cows, therefore they can be gentler while breeding, and they gain the loyalty of the cows. Young bulls often have to rush in to breed a cow while the herd bull is occupied elsewhere. Because of this younger bulls are not as leisurely with their breeding, are often rougher, and therefore are not preferred by the cows. During my elk research one herd bull bugled an average of 2 to 5 times every 5 minutes, while another herd bull of approximately the same age bugled 0 to 2 times every 5 minutes. The first bull was rough on the cows, while the second bull was very gentle.
That's how bulls have called for centuries, but since hunters began to bugle to attract elk, bulls have begun to change their bugling patterns, especially on public land. While it may be true that hunters are teaching bulls that a bugle they do not recognize is probably a hunter, it is more likely that hunters are changing the biology of elk. Aggressive elk that respond to human bugling are often killed by hunters, and the aggressive bugling style is slowly being bred out of current elk herds. Instead of frequently bugling bulls breeding most of the cows, it is the non-bugling or extremely wary bulls that breed more cows and survive to pass on the same traits to their young.
Bulls have also learned not to respond to a challenge unless they can actually see the other bull; they often ignore the sound of another bull, or they may push their herds away from aggressive calling. When I have called to nearby bulls during my research, most of them looked in my direction, but very few of them bugled back. On the other hand, when I bugled to bulls that were more than 100 yards away, that could not see me, they often responded. I've seen bulls respond to the bugling of other bulls in the same way. This leads me to believe that when a bull hears a bugle up close, it expects to see another bull.
Because elk ranges are traditional (both the bulls and cows returning to the same areas year after year) the cows may return to the same bull, as long as he is dominant. Because the bugle of each bull is distinctive (the bugling pattern remains about the same each season) the older cows readily return to the bulls they remember. They also choose the bulls by their scent. Because the bulls self-impregnate themselves during spraying, scraping and wallowing, each bull has its own individual scent. The combination of the urine, testosterone and possibly scent from the belly gland tells the cow not only that the bull is dominant, but which bull it is. If cow elk smell protein levels in urine (like whitetails do) they may also choose the healthiest bull by the amount of protein they smell in its urine. If the cows associate the sound and smell of the bull with dominance, health and gentleness, they often choose that particular bull as the herd bull, and breed with it.
