Antlers, the bony structures adorning the heads of deer, elk, and moose, are a distinguishing feature of these animals, collectively known as cervids. Unlike other cranial appendages, antlers undergo a remarkable annual cycle of growth and shedding. This process often prompts questions about whether shedding causes any discomfort.
The Antler Shedding Process
Antler shedding is a natural and painless process for cervids. It occurs when a specialized layer of cells, osteoclasts, actively resorbs bone at the pedicle, the bony base where the antler attaches to the skull. This process is triggered by a decrease in testosterone levels, usually following the breeding season. The gradual weakening of the bond allows the antler to detach.
The mature antler is a dead bone structure, lacking nerves and blood vessels. The formation of this abscission layer at the pedicle is a controlled physiological event, similar to how a human child loses a baby tooth. While the connection can take several weeks to weaken, detachment often happens quickly, sometimes with the antler simply falling off or being dislodged by a minor bump.
The Annual Antler Cycle
Antlers are true bone structures and represent one of the fastest rates of tissue growth. The annual cycle begins in early spring, with new antlers emerging from the pedicles. During this rapid growth phase, the antlers are covered by a soft, vascularized skin called velvet, which supplies nutrients and oxygen for development.
As the antlers reach their full size and harden, by late summer or early autumn, the blood supply to the velvet ceases. The velvet then dries and is shed, often assisted by the deer rubbing its antlers against vegetation. These polished, hardened antlers remain through the breeding season for display and competition. After the breeding season, decreasing daylight and hormonal changes signal the body to begin the shedding process, restarting the cycle.
Antlers vs. Horns
A common point of confusion is distinguishing antlers from horns. Antlers are unique to the Cervidae family, including deer, elk, and moose. They are composed entirely of bone and are shed and regrown annually, with new, often larger, sets developing each year.
In contrast, horns are found on the Bovidae family, such as cattle, sheep, goats, and most antelopes. Horns are permanent structures. They consist of a bony core covered by a tough, keratinous sheath, the same material found in human fingernails. Horns grow continuously throughout an animal’s life and are generally unbranched, though exceptions like the pronghorn, which sheds its keratin sheath annually, do exist.