Male deer lose their antlers as a natural, recurrent event. This annual shedding and regrowth is a distinctive characteristic that differentiates antlers from horns, which are permanent structures.
Why and When Antlers Are Shed
Antler shedding is primarily driven by seasonal changes in a deer’s hormonal balance, specifically a decrease in testosterone levels. This hormonal shift occurs after the breeding season, known as the rut, when antlers are no longer needed for dominance displays or fighting. Decreasing daylight hours in autumn signal these physiological changes, leading to a reduction in testosterone production.
The decline in testosterone triggers the formation of an abscission layer between the antler and the pedicle, the bony attachment point on the skull. This layer weakens the connection, causing the antler to loosen and eventually detach. The shedding process does not cause pain to the deer.
Antler shedding occurs from late winter to early spring, between January and March for many deer species. The exact timing varies based on factors like location, age, health, and nutritional status. Older, dominant bucks may shed earlier due to the high energy demands of maintaining their social status. Stress, poor nutrition, or a harsh winter can also prompt earlier shedding.
The Cycle of Antler Regrowth
After shedding, new antlers begin growing from the pedicles. This regrowth is fast, making antlers one of the most rapidly growing tissues in the animal kingdom. They can grow as much as a quarter-inch per day, and even up to an inch daily for larger species like elk.
During their growth, new antlers are covered in a soft, fuzzy skin called velvet. This velvet is rich in blood vessels and nerves, providing the oxygen and nutrients needed for the development of the underlying bone structure. Antlers initially form as cartilage and gradually mineralize into bone as they grow.
By late summer or early autumn, the antlers are fully grown and hardened, and the blood supply to the velvet diminishes. The velvet then dries, becomes itchy, and deer rub their antlers against trees and shrubs to remove it. This rubbing action helps polish the hardened antlers, preparing them for the upcoming breeding season. The size and complexity of new antlers are influenced by the deer’s age, genetic makeup, and nutritional intake, particularly minerals like calcium and phosphorus.
Life After Shedding for Antlers
Once shed, antlers become a valuable resource within the ecosystem, providing important minerals to various animals. Rodents like mice, squirrels, chipmunks, and porcupines frequently chew on shed antlers. They are attracted to the antlers for their rich mineral content, primarily calcium and phosphorus, which aid their bone and tissue development. Gnawing on these hard structures also helps rodents wear down their continuously growing teeth.
Other animals, including coyotes, wolves, and even deer, have been observed consuming shed antlers. Antlers also contain other minerals like magnesium, sodium, and various trace elements. The availability of shed antlers in the environment can be limited, as they are often quickly consumed or decompose, returning nutrients to the soil.