Sparring is a behaviour male moose commonly exhibit during the mating season, also known as the rut, which teaches them how to fight. They lock antlers and push back and forth, but “there is no attempt to injure each other,” according to the National Park Service.
Young males with “newly unsheathed antlers” are more likely to engage in sparring than older bulls, the Park Service article also notes.
Steve Adams, who shot this footage, told Storyful he spotted the trio in December 2019. “Three big boys!” he wrote of the video. Credit: Steve Adams via Storyful