Why Do Deer Lose Their Antlers?

By Adrienne Warber; Updated April 24, 2017
Why Do Deer Lose Their Antlers?Antlers provide details about a deer's health.

Have you wondered why deer shed their antlers? Deer grow and shed their antlers each year. Antlers serve a vital purpose in deer reproduction. Antlers also provide many details about a deer's health and age. The condition of the antlers can also affect when a deer sheds.

Antler Development

Antlers are a bone structure.

Antlers are bone tissue structures that grow from two base points, called pedicles, on top of a deer's head. As the antler grows, a soft tissue, known as velvet, containing veins and arteries covers the antlers and feeds nutrients to the growing bone structure. Deer grow antlers beginning in late April or early May and remain in a growth period through late August or early September. Antlers usually occur only on male deer. However, the Maryland Department of Natural Resources estimates that one female out of every 20,000 deer have small antlers.

The size and the number of points or tines on a deer's antlers depend upon his health, genetics, age and how well he ate during the winter. Antlers do not always grow the same size each year due to fluctuations in a deer's food supply and health. Older males can grow six or more points. Deer antlers differ from cattle horns because antlers fall off once a year, while horn grows year-round.

Purpose of Antlers

Antlers help to attract female deer for mating.

The main purpose of antlers is to attract female deer for mating. During mating season, when the antlers are growing, the male deer displays his antlers to a female deer and uses them to become the dominant male. The males will spar with each other using their antlers to establish dominance and claim females.

Antlers are also useful for defense against other deer and predators. When fighting other deer, deer hit each other with their antlers and often lock their antlers together. The deer sometimes are unable to unlock their antlers and end up starving to death.

Antler Maturity and Deterioration

Antlers become damaged in fighting.

During the summer, higher levels of the male hormone testosterone slows antler growth and the veins and arteries around the velvet constrict and cut off the blood supply to the antlers. By early September, the velvet dries and sheds, revealing the mature antler's bony structure for the autumn mating season.

Over time, antlers get damaged from fighting and general wear from daily life. By the end of mating season, some antler points may be significantly blunted or broken off.

Antler Shedding

After mating season the antlers are shed.

After deer mating season, deer shed antlers in early December through March. The amount of time that a deer retains his antlers depends upon his nutrition and genetics.

Antler shedding occurs over a 2- to 3-week period. The shedding process does not cause any discomfort to the deer. The tissue beneath the antler and the pedicles gradually disintegrates, causing the antlers to loosen. The antlers eventually fall off. New antlers will grow in the spring to prepare for a new mating season.