Reindeer, iconic inhabitants of Arctic and subarctic regions, possess impressive antlers. Many people wonder if these structures are permanent. Reindeer antlers do fall off each year, a process intricately linked to their physiology and the changing seasons.
The Antler Shedding Process
Reindeer antlers are bony structures shed annually, unlike permanent horns. This shedding process is driven by hormonal fluctuations. As the breeding season, or rut, concludes, a drop in male testosterone triggers the process.
At the base of each antler, where it attaches to the skull’s pedicle, specialized cells called osteoclasts break down bone tissue, creating a weakened abscission layer. This causes the antler to detach and fall off. Shedding antlers conserves energy, which is beneficial during harsh winter months when food resources are scarce.
The timing of antler shedding varies between male and female reindeer. Males typically shed antlers in late autumn or early winter, after the mating season. Females often retain theirs through winter and into spring, shedding in May after their calves are born. This extended retention provides an advantage, allowing pregnant females to compete for food buried under snow.
The Antler Regrowth Cycle
Once antlers have shed, the pedicle (the bony base on the skull) begins to heal. Soon after, new antler growth commences, typically in the spring. This regrowth is fast, making antlers one of the fastest-growing tissues in the animal kingdom.
During this rapid growth phase, developing antlers are covered in velvet, a soft, fuzzy skin. Velvet is rich in blood vessels and nerves, supplying the nutrients for bone growth. Antlers grow in size and branch out throughout the summer.
As summer transitions to late autumn, antlers fully mineralize and harden. The blood supply to the velvet ceases, causing it to dry and peel away. Reindeer rub their antlers against trees and shrubs to remove the remaining velvet, revealing the solid, polished bone beneath.
Antlers vs. Horns
Antlers and horns are distinct biological structures. Antlers, characteristic of animals in the Cervidae family, which includes deer, elk, and moose, are composed entirely of bone and are shed annually. They are typically branched, increasing in size and complexity with each successive year of growth.
Horns, in contrast, are found on animals belonging to the Bovidae family, such as cattle, sheep, and goats. Unlike antlers, horns are permanent structures never shed. They consist of a bony core covered by keratin. Horns grow continuously and are unbranched.
Reindeer are unique among deer species because both males and females typically grow antlers. While male antlers are usually larger and more massive, female reindeer also possess them. This sets reindeer apart from most other cervids, where antlers are primarily a male trait.