A family in Wyoming recently recorded a rarely seen event: a bull moose literally dropping an antler.

 “The moose shook his head and his paddle fell off right in front of us!” says Kim Eberhart, who saw the whole scene outside of her family's cabin. (The family doesn't want to identify the specific location out of fears the animal might be targeted by hunters.) “It was amazing,” she says.

Eberhart adds, “He then looked a little scared and stunned and was shaking his head and made a really mournful sound afterwards.”

In the video, shot by Eberhart’s uncle, a woman can be heard saying: “He's in pain, he's crying. Poor guy.”

But the moose more likely experienced a sense of relief, says moose biologist and author Bill Samuel of the University of Alberta. Moose and other deer relatives shed their antlers every year, and the process is thought to be painless, says Samuel.

"Usually both antlers are shed within hours or days of one another,” author Art Rodgers writes in the book Moose. “Bulls will occasionally try to speed up completion of the process by knocking the old antlers against trees to shed them."

Actually witnessing that brief event is quite rare, says Samuel. (Watch moose butting heads on a suburban street.)

Battle Gear 

Male, or bull, moose grow their antlers each year through the spring and summer. Female moose, called cows, don’t grow antlers. But males’ impressive headgear is made of bone that is an extension of the skull. When they first form, antlers are covered with a layer of skin called velvet, which nourishes the bone as it grows. When finished, the velvet sheds off, a process that the moose often accelerate by rubbing on trees. 

The antlers are fully formed by the early fall, when bull moose bellow to attract females and use their weaponry to battle rival males (watch an epic moose fight). After mating, the male and female go their separate ways.

Weighting up to 1,800 pounds (816 kilograms) and standing more than six feet (two meters) tall, moose are the largest species of deer in the world. Their antlers can spread six feet from end to end and weigh 40 pounds (18 kilograms). The animals range across northern North America, Europe, and Siberia.

Early Shedder?

Eberhart’s family shot the video on the day after Thanksgiving, leaving them surprised to see a moose dropping an antler so early in the season. 

Samuel says bull moose typically lose their antlers between mid-December and the end of January. Older bulls are known to shed earlier, although the moose in the video looks like a younger adult, he notes. 

Still, Samuel says he isn’t that surprised to find a moose dropping an antler earlier given the range of variability in nature.

Moose are struggling across much of their southern distribution in North America, including in Wyoming, says Samuel. A main cause is the rise of winter ticks, which are thriving in the relatively warmer winters the region has been experiencing over the past few years (with a likely tie to climate change). The ticks can become so plentiful on a moose that they can weaken it to the point of death. Calves are the most vulnerable. 
 
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