Antler Shed Science

Like most deer hunters, I love finding shed antlers. Perhaps it’s because each antler is as unique as a human fingerprint, or because it provides hints to where a buck lives, his age, his antler quality and even his dominance rank in the herd.

Regardless, I view each shed antler as a prize worthy of keeping, much like an arrowhead, and something tangible from a deer and a deer herd from which much can be learned.

As a young hunter I rarely found shed antlers, supposedly because they all were eaten by squirrels and rats—at least that’s what the local “experts” told me at the time. While it’s true rodents and numerous other animals, including deer, will chew on cast antlers, the main reason hunters don’t find shed antlers is because few bucks survive the hunting season in many areas. To make matters worse, most bucks that do survive in these overhunted areas are yearlings and their antlers are small, which makes them even more difficult to find.

The good news is that an increasing number of hunters are practicing Quality Deer Management, resulting in more bucks surviving each hunting season. This greatly increases your chances of finding a shed antler—especially one larger than a key-chain ornament. In fact, in recent years shed hunting has become so popular it has spawned its own association (North American Shed Hunters Association; shedantlers.org) and dogs trained specifically to locate shed antlers. Some hunters even pay for access to properties on which to search for shed antlers.

The process that governs antler growth and casting in deer is quite fascinating. Antler growth occurs during the spring and summer months when the male hormone, testosterone, in bucks is low. As day length begins to shorten in late summer, testosterone levels rise to a critical threshold that triggers antler mineralization (hardening) and velvet shedding. This typically occurs in September in most of the South. Testosterone levels remain high during the breeding season, dropping in late winter or early spring as day length begins to increase. This rapid decline in testosterone causes antler casting, and the process repeats.

Beyond the size of a shed antler, few hunters realize how much additional information it can provide—not just about the individual deer that dropped it, but also about the overall health of the deer herd and its habitat.

The most obvious information provided by a shed antler is the approximate age and antler size of the buck that dropped it. In most cases, I double the score from one antler and add a conservative inside spread measurement to get an idea of the buck’s approximate gross Boone and Crockett (B&C) score. Then, using age and average gross B&C data from other bucks harvested on the same property, I place the buck into one of four age categories—yearling (or 1 1/2 years old), 2 1/2, 3 1/2 and 4 1/2 years old or older. I also refer body characteristics from my trail-camera photos if the buck’s antlers are easily recognizable. Trail-camera photos also can be useful to estimate tine and beam length in situations where they have been eaten by rodents.

With enough shed antlers, you can not only get an idea of the bucks that survived the previous hunting season, but you also can estimate the upcoming season’s buck age structure and antler potential. If the shed has any unique features such as forked tines, drop tines or abnormally long or short points, they can be useful for identifying the same buck in future years. Nothing adds more enjoyment and satisfaction to the harvest of a mature buck than to have shed antlers from the same buck during one or more previous years.

The timing of antler casting also is important. Research has revealed that both nutrition and dominance rank can influence when a particular buck will cast its antlers. For example, Michigan researcher John Ozoga noted that providing supplemental feed to bucks delayed their average antler casting date by more than a month from late December to mid February, with some bucks even carrying antlers into March.

Likewise, bucks under extreme nutritional stress will cast their antlers early, some even before the end of hunting season. This situation is particularly common in eastern hardwood forests that rely on annual acorn crops. In years of widespread acorn failures, bucks often shed their antlers several weeks earlier than normal. Nutritional stress also can result from extreme or prolonged rutting activity, especially if the buck did not enter the rut in prime physical condition, or if the buck had inadequate nutrition immediately following the rut.

With deer season extending later and some bucks shedding antlers early, hunters should be careful when trying to take a doe at the end of the season.

Early antler casting can be problematic on properties practicing QDM and trying to protect young bucks. Nothing hurts worse than mistakenly killing a buck that has cast his antlers early while the hunter trying to meet doe harvest goals for a property. This happened on my hunting property a few years ago in north Georgia when an abnormal number of bucks cast their antlers in late-December, a full month before normal. That year, we lost a 3 1/2 and a 5 1/2-year-old buck, which stung. Since then, we have been extra cautious late in the season and have relied on trail-camera data to inform us of any early casting.

Shed Hunting Tips

• Use trail cameras to monitor the timing of antler shedding. Begin hunting sheds as soon as most or all bucks have dropped their antlers (timing will vary geographically).

• Concentrate your search in the following areas: 1) winter food sources, especially cool-season food plots; 2) bedding areas or winter cover; 3) along trails and in bottlenecks; and 4) near water if water is limited on your hunting land.

• Focus on areas along travel routes where deer must jump—like fences, ditches or creek crossings—as antlers are often jarred loose at these locations. Places where brush is especially dense along trails are also productive.

• Pay close attending to deer beds in leaf litter. These are productive because of the increased chance of finding a matched set or spotting very small shed antlers.

• Walk slowly and methodically in a grid-like pattern. Look nearby but also to your side and downrange. Wide-angle, low-magnification binoculars are highly recommended. 

• Use modern technology, like the HuntStand app (HuntStand.com) to record the location of each shed on a map of the property. These often are great hunting locations in subsequent years, especially late in the season as the timing of antler casting approaches and bucks settle into their winter movement patterns.

Researchers also have documented that the interaction between a buck’s dominance rank and the length of the breeding season can affect timing of antler casting. In general, a buck’s dominance rank is affected by age, body weight and testosterone levels—all of which typically increase with age, at least until 5 1/2 or 6 1/2 years of age.

However, the effects of these factors appear to vary according to latitude (North vs. South). In northern latitudes, where the rut is generally shorter and more intense, dominant bucks generally cast their antlers earlier than lower-ranking bucks. This is presumed to be caused by elevated testosterone levels during the shorter breeding period, followed by a rapid decline in these hormone levels and antler casting. The survival advantages of this are clear—bucks in these harsher environments can terminate breeding earlier and rebuild necessary body reserves to survive the brutal winter.

In contrast, Kenneth Forand and others at the University of Georgia documented that dominant bucks in the South generally shed their antlers later than lower-ranking bucks. They speculated this was due to the longer and less intense breeding season during which bucks face lower stress levels compared to northern deer. This allows bucks in southern latitudes to remain in better physical condition, maintain elevated testosterone levels, and have a competitive breeding advantage over lower-ranking bucks.

Physical and/or nutritional stress caused by diseases, parasites and injuries also can result in premature antler casting. In southern ranges where hemorrhagic disease outbreaks are common, bucks that survive infection often cast earlier during the year of infection. Heavy infestations of internal or external parasites also can cause earlier antler casting. In most cases, heavy parasite concentrations are indicative of overpopulated, stressed deer herds in need of immediate management attention.

When latitude, nutrition, health and buck age structure remain relatively constant from year to year, such as is common in many managed deer herds, individual bucks generally cast within a few days of the same date each year. For example, a study by Dr. Harry Jacobson at Mississippi State University involving 24 captive bucks revealed an average of only 4.4 days variation in annual casting dates among individual bucks, with the longest being 17 days for one buck.

Given the above, it is clear that much insight can be gained from shed antlers. Not only does the antler reveal a buck’s relative age and antler quality, it also provides insight as to the status of the overall deer herd as it relates to habitat quality and nutritional health. If you regularly find cast antlers before the end of the hunting season in your area, there’s a good chance nutrition is limiting or the herd is stressed in some way. On the other hand, if bucks regularly hold their antlers well beyond the normal casting time, nutrition likely is adequate. Keep in mind that early casting by mature bucks is more common in the North than in the South.

So, the next time you find a shed antler, take the time to consider all the information it can provide. With enough shed antlers from a given property over time, you can monitor the status of your deer herd and make informed management decisions in the future. By the way, shed antlers also make nice additions to your bookshelf and mantle not to mention the subjects of stories and memories.

Editor’s Note: Brian Murphy is a wildlife biologist with more than 30 years of experience researching, managing and hunting deer. He has worked as Wildlife Research Coordinator for the University of Georgia and CEO for the Quality Deer Management Association. Brian currently serves as V.P. of Strategic Partnerships for HuntStand, the world’s largest and most-used hunting application huntstand.com.