Elk antlers, unlike the permanent horns of other animals, undergo a remarkable annual cycle of growth and shedding. This process is essential for their reproductive success and survival.
The Antler Cycle: Growth and Shedding
The antler cycle begins in early spring, when elk shed their old antlers. Immediately after shedding, new antlers begin to grow from bony protrusions on the skull called pedicles. This growth is incredibly rapid, making antlers one of the fastest-growing tissues in the animal kingdom; they can grow up to an inch per day.
During growth, developing antlers are covered in velvet, a soft, fuzzy skin rich in blood vessels and nerves. This velvet provides oxygen and nutrients for rapid bone formation. As antlers reach full size by late summer or early fall, bull elk testosterone levels surge. This hormonal shift stops blood supply to the velvet, causing it to dry and peel. Elk then rub their antlers against trees and shrubs to remove the remaining velvet, which hardens and polishes the bony structures.
After the breeding season, or rut, concludes in late winter or early spring, elk testosterone levels decline. This hormonal decrease weakens the bone connection at the pedicle. A specialized tissue layer forms, causing antlers to loosen and fall off, a process known as casting. This shedding is not painful for the elk.
Why Shedding is Essential
Shedding antlers serves several purposes for elk. Regrowing larger, stronger racks each year allows for displaying dominance and competing for mates during the rut. Females favor males with impressive, symmetrical antlers, as these often indicate good health and genetic fitness.
Shedding also allows elk to replace damaged antlers, ensuring a complete set each year. Maintaining large, heavy antlers outside the breeding season is metabolically expensive, requiring significant energy and calcium. By shedding them after the rut, elk conserve energy and resources during leaner winter months when food is scarce, focusing on survival and recovery. While primarily used for mating, antlers also defend against predators like wolves. Elk that shed antlers earlier in winter may face a higher predation risk.
Antlers Versus Horns
Antlers and horns are fundamentally different structures. Antlers are bony extensions that grow from the skull and are shed and regrown annually. They are characteristic of the Cervidae family, including deer, moose, and elk. With the exception of caribou, only male cervids typically grow antlers.
In contrast, horns are permanent structures composed of a bony core covered by a sheath of keratin, the same material found in human fingernails. Horns are not shed and continue to grow throughout an animal’s life. Animals such as cattle, sheep, goats, and bison possess horns, and both sexes often have them.
The Fate of Fallen Antlers
Once elk shed their antlers, these bony structures become an integral part of the ecosystem, providing a valuable source of minerals. Rodents like squirrels, mice, and porcupines, along with other scavengers, chew on fallen antlers to obtain calcium, phosphorus, and other trace minerals. This activity helps wear down their continuously growing teeth and recycles nutrients back into the environment.
Human activity also plays a role in the fate of shed antlers. “Shed hunting” is a popular pastime, where individuals search for and collect discarded antlers in forests and fields. Many states regulate when and where shed hunting is permitted to minimize disturbance to elk during sensitive times.