By Matt McKnight
EATONVILLE, Wash. (Reuters) - Each year, as the days of summer dwindle and the colors of fall begin to emerge in the U.S, Pacific Northwest, an otherworldly sound fills the air.
In the foothills of Mount Rainier at Northwest Trek Wildlife Park, about an hour from Seattle, the eerie bugling sounds of elk ring out, as mating season has begun.
Roosevelt elk, the largest of the four surviving subspecies in North America, have entered their annual rut season — a time when bull elk are vying for female partners and make elaborate sounds to show their dominance over other members of the herd.
"For most of the year, they're all friends. They form what's called a bachelor herd, which are all the adult males when it's not the breeding season, go and hang out together," explains Northwest Wildlife Trek keeper Skylar King. "Now that changes at the end of the summer, those hormones start changing."
These large elk can also be found sparring with other members of the herd, exerting their dominance and attempting to find out where they stand during the year's mating period.
"The goal for the males during the breeding season is to be the only boy with all of the females, and to keep all the other males away from the girls." says King, who likens the sparring to an arm wrestling match as opposed to a knife fight.
"You'll start to see them wallow in the mud, darken their bodies like a spray tan for humans. They'll flick urine on themselves to make them smell irresistible to the ladies. There's a lot of very unique behaviors."
Even the younger male elk take part in the process. They lock antlers and imitate the behavior of the older bull elk as a form of practice, for when they will actually be competitive during rut season.
King says that elk's rutting season can be witnessed in various parts of North America during early autumn, but it's dependent upon climate and herd subspecies.