Moose are the largest species of deer in the world, and like their smaller relatives the males shed old antlers and grow new ones every year. But the process is rarely captured on film, so the Wyoming family that shot this video got very lucky.
Unlike horns, which are made of bone as well as keratin, antlers are pure bone and grow directly out of the skull. Every winter the moose's antlers fall off to make room for the new growth. Usually older males shed antlers earlier in winter while younger moose shed later in the season, so this seemingly young male dropping an antler just after Thanksgiving came as a surprise.
In the video, which is accompanied by moose trivia from National Geographic, the moose is just moseying around until a vigorous full-body shake causes half of his headgear to fall right off. He seems taken by surprise, and the family's kids react with distress and consternation, worried that the animal was feeling pain.
But as far as scientists know, the process is painless, and members of the deer family will try to accelerate the shedding by rubbing their antlers up against tree trunks. It's likely the moose felt relief, according to moose biologist Bill Samuel.
It is probably disorienting to walk around with one headlight out, considering that a pair of antlers can weigh up to 40 pounds. But moose usually shed the second antler within a few hours or days of shedding the first, so this guy likely didn't have to feel unbalanced for long.