Why Do Moose Lose Their Antlers?

By Carolyn Csanyi; Updated April 24, 2017
Male moose shed antlers each year after mating season.

Only male moose have antlers. The antlers are broad and flat, and shed at the end of every mating season.

Antler Function

Female moose choose mates based on horn size. Moose in their prime, 5 to 12 years old, have the largest antlers. Regrowing them each year reflects the health and condition of the animal as a mate.

Antler Growth

Antler growth is tied into testosterone production. They grow to full size in the spring and summer months, while testosterone levels are building for the fall mating season. Calcium for antler-building comes from food and from the moose's own bones, especially the rib cage.

Antler Shedding

When mating season is over, testosterone levels fall, and the bone at the base of the antlers begins to dissolve. The antlers become loose and eventually fall off, usually in November to mid-January. Some of the antler calcium is resorbed into the moose's body before shedding. Moose conserve energy in winter by not having to carry around the heavy antlers.

About the Author

Carolyn Csanyi began writing in 1973, specializing in topics related to plants, insects and southwestern ecology. Her work has appeared in the "American Midland Naturalist" and Greenwood Press. Csanyi holds a Doctor of Philosophy in biology from the University of Wisconsin at Madison.