Moose shed their antlers every year as part of a natural biological process. This cycle of growth and shedding allows male moose to develop antlers for specific purposes each year. Unlike permanent structures like horns, antlers are grown anew each spring and summer.
The Annual Cycle of Antler Growth and Shedding
The antler cycle for a moose begins shortly after shedding the previous set, typically in late winter or early spring. New antlers emerge from bony protrusions on the skull called pedicles. These rapidly growing structures are covered in a soft, fuzzy skin known as velvet, which is rich in blood vessels and nerves, providing the necessary nutrients for bone development. Antlers are among the fastest-growing tissues in the animal kingdom, capable of growing an inch or more per day during their peak.
Once antlers reach full size in summer, hormonal changes occur, particularly an increase in testosterone. This hormonal shift causes the blood supply to the velvet to constrict, leading it to dry out and die. The moose then rubs its antlers against trees and shrubs to remove the itchy, dead velvet, revealing the hardened, bony antlers underneath.
Shedding typically occurs in late winter, between December and March, though timing varies by location and individual moose. A specialized layer of bone, called the abscission layer, forms at the antler’s base, gradually weakening its connection to the skull. Decreased daylight and falling testosterone levels after the breeding season trigger this process, causing the antlers to detach and fall off, sometimes one at a time.
The Purpose of Antlers and Their Fate After Shedding
Moose antlers serve important functions, primarily related to reproduction and social hierarchy. During the autumn mating season, known as the rut, male moose use their large antlers to display health and strength to potential mates. They also use them to establish dominance over rival males, often engaging in displays or sparring matches where antlers lock together. While less common, antlers can also provide defense against predators.
Once the breeding season concludes and antlers are shed, their usefulness to the moose ends, but their role in the ecosystem continues. Shed antlers are a valuable source of calcium, phosphorus, and other minerals, often scarce in forest soils. Various forest dwellers, including rodents like mice, squirrels, and porcupines, and other deer, gnaw on discarded antlers for essential nutrients.
This consumption and decomposition of antlers contribute to nutrient cycling within the forest environment. The minerals are eventually released back into the soil, enriching it and supporting plant growth. These discarded antlers play an important role in sustaining other life forms and the overall health of the ecosystem.