Those Fascinating Deer Antlers

Deer antlers are one of the fastest-growing tissues in all of nature. Growth is regulated by hormones controlled by the photoperiod, or length of day.
Those Fascinating Deer Antlers

Today’s deer hunter is not unlike his ancestors in many ways. Though the technology and needs have certainly changed, we still hunt to feed our families and answer a primal urge. And like primeval man, we are enamored with antlers.

You can see this fascination by looking at the etchings and paintings on cave walls the world over, where ancient hunters created their own trophy room long before the art of taxidermy was perfected. They also used antlers and horns in a practical way, making everything from tools, weapons and ceremonial garb from them. Antlers were often featured prominently in ceremonial dances to celebrate the prowess of the tribe’s best hunters.

Modern hunters are so infatuated with antlers that they spend inordinate amounts of time and money helping deer grow them. Food plots, mineral licks, protein supplements, habitat manipulation and management — many think about it 24/7/365. In spring and summer we watch antlers grow, and that begets questions: How do they grow? What are they made out of?  What is this furry velvet we see early in their development, and why does it go away?

Antlers are one of the fastest growing tissues in all of nature. The process for whitetails is regulated by hormones controlled by the photoperiod, or length of day. The primary hormones responsible for antler growth are testosterone and IGF (insulin like growth factor). Biologically, fluctuating testosterone levels initiate the peeling off of the velvet and the casting off of the antlers, while IGF that is produced in the liver promotes actual antler growth. As the days grow longer from winter to spring to summer, a corresponding drop in melatonin production kick-starts the hormone cycle for antler growth. Without diving into too much biology, basically a buck’s brain measures the length of day by the amount of melatonin produced. In turn this influences testosterone and IGF levels. This is why the bucks that are late in the velvet shedding process are usually yearling bucks and older bucks past their prime — they have lower levels of testosterone than prime-of-life bucks.

Antler growth begins with the pedicel, located on the frontal portion of the skull and which is the base from where antlers form. “Buttons” begin to grow from the pedicels when bucks are about six months old. During the spring and summer growing season the antlers are covered in a very fine, soft membrane we call velvet. Underneath this furry membrane, a rich supply of blood and nutrients flows through veins running on the outside of the antlers and back down to the base. During the growing stages, antlers are high in water and blood content and low in dry matter. The dry matter at this stage is around 80 percent protein and 20 percent phosphorous and calcium. Once hardened, antlers are about 60 percent phosphorous and calcium and 40 percent protein.

When in velvet, antlers are very vulnerable. Bucks are intuitively aware of this and are very careful during the growth process, one reason it’s common to see bucks out in the open when they are in velvet. Injuries to the velvet can result in abnormal points or, at times, complete deformation. As a side note, leg and pedicel injuries can also lead to deformed antlers. Injuries on the rear legs affect the opposite side antler, where front leg or shoulder injuries will affect the same side. Research shows this oddity may be from the buck’s ability to pull or redirect nutrients for healing the injured leg. Also, injuries to the pedicel can happen from buck fights during the rut, which can cause part of the pedicel to shed with the antler. If these injuries are bad enough, they can sometimes affect antler growth for several years.

Following the summer solstice (June 21 in 2018), days start getting shorter and the testosterone levels in bucks begin to rise. This slows the antler growth cycle, which begins the process of hardening of the antlers. Bucks now grow what we call the “burr” at the base of the antler. The burr cuts off the blood supply to the velvet. In less than a day the drying velvet is rubbed off on trees and bushes, leaving the buck with a blood-stained rack he will continue to polish for several days.

Rarely does a buck not shed his antlers, instead keeping velvet-covered antlers that continually grow throughout the year. This is known as cryptorchidism, and these bucks are often called “cactus bucks.” Cryptorchidism is the result of an injury or castration of the testes which alters testosterone levels. The age at which the injury occurs will determine the severity of antler deformation or interruption in the normal antler cycle. An older buck that has a testes injury or castration while in hard antler will likely shed its antlers early due to the sharp decrease in testosterone production. The following season, the buck may grow a rack that is permanent and stays velvet-covered and growing.

For most of us, deer hunting is a way to reconnect with Mother Nature, a time to escape the pressures of the go-go world in which we live while providing the finest organic protein on earth to our families. Yet, like ancient man, the modern deer hunter also reveres exceptional antlers. Because they are rare, they take our breath away and leave us in awe. And so, like our ancestors, we dance.

Do you have any unique antler stories you’d like to share? Drop me a note at, I’d love to hear from you!


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