Moose are the largest members of the deer family, known for the expansive, shovel-shaped antlers that crown the heads of males.
The Annual Antler Shedding Process
Moose shed their antlers each year, typically in late winter or early spring (December to March). Antlers are distinct from horns; they are solid bone structures that grow from bony protrusions on the skull called pedicles. The shedding is a natural part of their annual cycle, primarily regulated by hormonal changes.
As the breeding season concludes, a decrease in testosterone levels in bull moose triggers the reabsorption of calcium at the pedicle. This weakens the connection between the antler and the skull. Eventually, the antler detaches, often with minimal effort, sometimes while rubbing against a tree. It is a painless process, comparable to a human losing a baby tooth.
Often, one antler will fall off before the other, leaving the moose temporarily lopsided. The remaining antler usually sheds within a few days to a few weeks. This annual shedding allows for the growth of new, often larger antlers.
The Remarkable Cycle of Antler Regrowth
After shedding, moose begin regrowing a new set almost immediately. This regrowth phase is one of the fastest rates of bone growth observed in the animal kingdom. Specialized cells at the pedicle rapidly initiate new bone tissue formation.
During initial growth, developing antlers are covered in velvet, a soft, fuzzy skin. Velvet is richly supplied with blood vessels and nerves, delivering essential nutrients and oxygen to the rapidly growing bone. The rich blood supply supports rapid antler development.
Throughout spring and summer, antlers grow, expanding in size and complexity. By late summer or early fall (August or September), they reach full size and harden. The blood supply to the velvet then diminishes, and it dries, cracks, and peels away, a process known as “velvet shedding.” Moose rub their antlers against trees and shrubs to remove remaining velvet, revealing the hardened bone.
The Fate of Shed Antlers
Shed moose antlers are an important component of the forest ecosystem, providing calcium, phosphorus, and other minerals for various forest dwellers. Rodents, such as mice and squirrels, and larger animals like porcupines, frequently gnaw on shed antlers to supplement their diets.
Over time, shed antlers decompose, returning minerals to the soil and contributing to the forest’s nutrient cycle. While most shed antlers are consumed by animals or naturally decompose, some are sought by humans through “shed hunting.”