As fall approaches, the Roosevelt elk enter the rut, the mating period for their species during which many of their distinctive behaviors emerge. After spending several months developing velvet-covered antlers, the bulls strip away the velvet and sharpen the tips of these bony structures by rubbing them against trees, shrubs and grasses. Here, bearing an impressive set of seven-point antlers, a bachelor bull looks up to survey its surroundings before returning to grazing in a field near Dry Lagoon.
Rutting bulls will compete to attract a harem by bugling and spraying themselves with urine to create a scent that appeals to cows. Bulls may challenge each other for control over a harem by bellowing at each other and walking in parallel to size up each other’s physical prowess. If neither decides to back down at this point, conflicts escalate to antler wrestling, in which bulls can sustain serious injury. Here, the bull featured in our photo from earlier this year shows signs of having lost his harem to a challenger, but is still attempting to attract cows and drive away rivals:
Bulls rarely eat while in control of a harem, and can lost up to twenty percent of their body mass during breeding season. This bull’s weight loss likely made him vulnerable to a challenge from a rival bull, in which he appears to have sustained an eye injury during antler wrestling. Not content to remain a bachelor, he continues to bugle and make his presence known to potential mates and rivals.
Elk cows are only fertile for approximately two days out of the year, so a bull with a harem must keep close track of which cows are in estrus if he is to mate successfully. To do this, the bull smells and tastes his cows frequently.
Young bulls not mature enough to mate will frequently live on the periphery of harems during the rut, grazing alongside the cows and occasionally honing their skills for future years.
Two young bulls practice antler wrestling
Meanwhile, the calves the joined the herd in June stay close to their mothers and continue to suckle and grow.