Elk
The elk rut takes place between the middle of August and the middle of October, depending on the climate in which they live. The elk rut occurs around the same time of year throughout the United States. For example the peak rut in Idaho occurs between September 20th and 25th, while the peak rut in New Mexico occurs around September 14th (Michels). The rut tends to last somewhere between 20 and 45 days. This varies on latitude, for in southern areas spring arrives earlier and fall arrives later giving elk a longer calving season, therefore the rut lasts longer (Michels). During the rut elk frequently use areas around fresh water, and tend to bed in heavy timber five to six hours per day (Bowyer 579). A cow elk will remain in estrus for 12 to 15 hours, if they are not bred during this time frame they will normally have another estrus cycle 18 to 28 days later (Michels).
Elk use several different vocalizations during the rut. Some are made only by a certain sex or age class, and each is used for a different reason. The first of which being the cohesion call which is made by both sexes of elk, and is used to locate one another (Bowyer 225). An alarm squeal is made by both sexes of elk when they are on alert, during the rut these are used frequently by young bulls being run off by the herd bull (Bowyer 228). Satellite bulls frequently spar with one another during the rut, and in turn make sparing squeaks (Bowyer 228). A bugle is a vocalization made exclusively by bulls. A bugle can be directed toward other bulls or toward cows. A bull will direct his bugle toward his cows while gathering them or while chasing an estrus cow. A herd bull will direct his bugle toward another bull to express his dominance over the herd, while a satellite bull may use his bugle to challenge the herd bull (Bowyer 229). Yelping also known as “grunting” is usually only made by herd bulls when they are “excited”. They are made more often while interacting with cows than with other bulls. “Yelping commonly was accompanied by contractions of the penile region with simultaneous emission of short spurts of urine” (Bowyer 230).
The rut has five phases: the pre-rut, the first breeding phase, the first rest phase, the second breeding phase, the second rest phase, and the third breeding phase (Michels).
The pre rut takes place from mid-August through the beginning of September. During the pre-rut bulls begin bugling and gathering their herds. Bulls will bugle to attract cows as well as to express dominance over other bulls (Michels). A “herd” bull is the dominant bull in a herd. Younger, smaller bulls are known as satellite bulls, as they tend to cling to the edges of a herd trying to pick up any cows willing to leave the herd. Larger satellite bulls will challenge the herd bull to try and take control of the herd. These challenges include a good deal of bugling as well as fighting (Michels).
The first breeding phase of the rut takes place between the beginning and the middle of September. This is when the three year and older cows come into estrus (Michels). During this time herd bulls bugle to keep their cows close by, they also answer the bugles of satellite bulls to let them know they are still dominant (Michels). A herd bull will also bugle while approaching a cow in estrus so the cows become familiar with his bugles (Michels).
The first rest phase of the rut occurs between the middle and the end of September. At this time the older cows are predominantly out of estrus and the younger cows have not yet come into estrus. During the rest period satellite bulls will try to join the herd while the herd bull is resting (Michels). The second breeding phase of the rut takes place three to four weeks after the first breeding phase (Michels). This is due to younger cows coming into estrus, as well as older cows that were not breed on their first estrus cycle coming back into estrus. Herd bulls are less aggressive towards satellite bulls at this phase in the rut due to exhaustion (Michels). The second phase of the rut may have the most bugling activity due to the combination of the testosterone levels of the younger bulls rising, and the herd bull still trying to maintain control of the herd.
The second rest phase of the rut occurs around the middle of October. By this time the original herd bull usually does not have control of the herd, due to a great decline in physical condition. Terry Bowyer states, “Elk were observed feeding in the following percentages of observations: master bulls 24%; bachelor bulls 53%; yearling males 62%; cows 64%; and calves 62%” (Bowyer 577). (Bowyer uses the terms “master bulls” and “bachelor bulls” which have the same meaning as “herd bulls” and “satellite bulls”.) Herd bulls do not have time to feed during the rut due to constantly fighting other bulls as well as chasing and breeding cows (Michels).
Occasionally a third breeding phase will occur. This will usually take place around the end of October or early November. This is a result of yearling cows coming into estrus for the first time or two year old cows coming into a second estrus cycle (Michels). Since most of the herd bulls have left the herd by this time of year, the breeding is usually done by the younger satellite bulls. After this phase the rut is over, most bulls will leave the cows and form bachelor herds to spend the winter with; however young bulls will usually remain with the cows throughout the winter (Michels).
Read more about this topic: Rut (mammalian Reproduction)