Reindeer, known for their cold-weather adaptations and striking appearance, possess a unique feature that sets them apart from most other deer species: their antlers. These bony growths are a subject of curiosity, particularly regarding which reindeer grow them and the biological processes involved in their annual cycle. Unlike most other deer, both male and female reindeer can grow antlers.
Who Has Antlers Among Reindeer?
The size and timing of antler growth and shedding vary between sexes. These variations can also depend on factors such as age, health, and whether the reindeer are wild or domesticated.
Male reindeer begin growing their antlers in early spring, around February. These can reach considerable sizes, up to 50 inches in length. They use these fully developed antlers during the autumn mating season, known as the rut, to establish dominance and compete for females. After the rut, in late autumn or early December, male reindeer shed their antlers.
Female reindeer also grow antlers, though theirs are generally smaller and less branched, reaching up to 20 inches. Female antlers start growing a few weeks after the males’, around May. Females often retain their antlers throughout the winter, shedding them later in the spring, often after giving birth to their calves.
This extended retention provides females with an advantage during the harsh winter months, allowing them to defend foraging areas and access food buried under snow, which is especially important for pregnant individuals. While most female reindeer grow antlers, a small percentage, approximately 3-5%, may not develop them. Young reindeer grow their first antlers before reaching puberty.
The Amazing Cycle of Antler Growth
Reindeer antlers are bony structures that grow annually from permanent outgrowths on the skull called pedicles. They are not horns, which are permanent and made of bone and keratin. Antler growth is remarkably rapid, making them one of the fastest-growing tissues in the animal kingdom, capable of growing up to one centimeter per day.
During their growth phase, antlers are covered in a soft, fuzzy skin known as “velvet.” This velvet is rich in blood vessels and nerves, providing the necessary nutrients and oxygen for rapid bone development. Once the antlers have reached their full size, by late summer or early autumn, the blood supply to the velvet ceases, causing it to dry and become itchy. Reindeer then rub their antlers against trees and other vegetation to shed this dried velvet, revealing the hardened bone underneath.
The shedding of antlers is a natural annual process, after which a new set begins to grow, continuing the cycle. Antlers serve multiple functions for reindeer, including display for attracting mates, establishing dominance within the herd, and defense against predators. They are also used for practical purposes, such as digging through snow to find lichen and other vegetation during winter. The size and complexity of antlers can also be an indicator of an individual’s health and nutritional intake.