Many female reindeer, unlike most other deer species, possess antlers throughout the winter months. This unique characteristic sets them apart in the deer family, where typically only males grow antlers. This adaptation plays a significant role in their survival, particularly in the challenging environments they inhabit.
The Antler Cycle in Reindeer
Reindeer antlers undergo an annual cycle of growth and shedding, but the timing differs between sexes. Male reindeer typically begin growing their antlers in February and shed them in late autumn or early winter, often after the breeding season. By December, most mature male reindeer no longer have antlers.
Female reindeer, however, follow a distinct antler cycle. They begin growing their antlers later than males, usually in May, and retain them throughout the winter, often until late winter or spring. This difference in shedding time is a defining feature of reindeer.
Why Females Retain Antlers in Winter
Female reindeer retain their antlers through the winter due to several advantages, especially for pregnant females. Antlers serve as important tools for competition, particularly when food resources become scarce under deep snow. Females use their antlers to defend prime foraging areas, scraping away snow to access lichen and other vegetation. This access to consistent nutrition is important for their survival and the development of their calves during pregnancy.
The presence of antlers allows dominant females, who often have larger antlers, to secure better feeding spots against other females and even males who have shed their antlers. This provides a reproductive advantage, as well-nourished pregnant females are more likely to produce healthy offspring. Hormonal influences help induce and maintain the hard antler state in female reindeer throughout the winter. This hormonal mechanism helps synchronize the antler cycle with their reproductive cycle, ensuring antlers are present when most needed for intrasexual competition.
Antler Shedding and Regrowth
The shedding period for female reindeer varies, largely depending on their reproductive status. Pregnant females typically retain their antlers until after they give birth in the spring, often shedding them within a few days before or after calving, usually in April or May. This extended retention allows them to protect their newborns from predators and compete for food during the vulnerable calving season. Non-pregnant females, in contrast, may shed their antlers earlier, sometimes in late winter or early spring.
Shortly after shedding their old antlers, female reindeer begin the regrowth process for a new set. This rapid regrowth prepares them for the next annual cycle. The new antlers initially grow with a soft, fuzzy covering called “velvet,” which supplies nutrients, before hardening and losing the velvet later in the season. This continuous cycle ensures female reindeer are equipped with antlers for the demanding winter months each year.