Deer antlers are bony extensions emerging from a male deer’s skull. Unlike horns, which are permanent and made of keratin, antlers are composed of bone and are shed and regrown each year. Their primary purpose is display and competition among males during the breeding season, signaling a buck’s health and genetic quality to influence mate selection and establish social hierarchies.
First Antler Appearance
Male white-tailed deer begin developing their first set of antlers, often called “buttons” or small spikes, around 6 to 10 months of age. These initial growths are small, appearing as short, unbranched projections. A buck fawn born in spring will show these first signs of antler development by its first autumn or winter. This early growth is significantly influenced by the fawn’s overall health and nutrition, with abundant, nutrient-rich forage leading to more robust initial antler development.
The Yearly Cycle of Antler Growth
After their initial appearance, deer antlers follow an annual cycle of shedding and regrowth. Most male deer shed their antlers in late winter or early spring, between January and March, though timing can vary by region and individual. New antler growth commences almost immediately after shedding in late spring, emerging from permanent bony structures on the skull called pedicles. During this rapid growth phase, the antlers are covered in a soft, fuzzy skin known as velvet, which is rich in blood vessels and nerves. This velvet supplies the oxygen and nutrients necessary for rapid bone growth, which can reach up to an inch per day for larger species.
As summer progresses and the antlers reach their full size by late August or September, the blood supply to the velvet diminishes. The velvet then dries, cracks, and peels away, often aided by the buck rubbing its antlers on trees and shrubs. This process exposes the hardened bone of the mature antler. These hard antlers are then used throughout the breeding season, or rut, for sparring with rival males and establishing dominance. The entire annual cycle of antler growth and shedding is primarily regulated by seasonal changes in daylight, which in turn influence hormone levels, particularly testosterone.
What Influences Antler Size and Shape
Several factors contribute to the ultimate size and shape of a deer’s antlers beyond their first appearance. Age plays a significant role, as bucks produce larger and more complex antlers as they mature. Antler development peaks when a buck reaches between 5 and 7 years of age, after which antler size may begin to decline. Allowing bucks to reach older age classes is a common management strategy to promote larger antlers within a population.
Nutrition is another determinant of antler quality. Antler growth is an energetically demanding process, requiring substantial amounts of protein, calcium, and phosphorus. Deer with access to high-quality forage throughout the year, especially during the spring and summer growth periods, can allocate more resources to antler development. Conversely, poor nutrition or environmental stress, such as drought, can lead to smaller antlers.
Genetics also influences antler potential, as inherited traits contribute to a buck’s capacity for size and symmetry. While good nutrition can help a deer reach its genetic potential, a deer with limited genetic potential will not grow large antlers regardless of diet.