What Causes “atypical” or Non-Typical Antler Growth in Elk and Deer? (Ask the Biologist)

Although it’s normal for antlers to vary greatly in size, sometimes deer or elk will have unusual to extreme antler growth.
This Estes Park bull elk attracted a lot of attention with his nontypical antlers. Photo by Jim Austin.
This Estes Park bull elk has been attracting a lot of attention with his unusual, nontypical antlers. Photo by Jim Austin.

In this segment of “Ask the Biologist,” Colorado Outdoors Online reader Iolanthe Culjak asks: “What causes unusual antler growth in elk and deer?”

Culjak, a resident of Estes Park, sees elk almost daily during her commute to and from work in this mountain town famous for its elk population. Yet, Culjak did a double take when she saw a bull elk sporting strange, “melted looking” antlers.

Although it’s normal for antlers to vary greatly in size, sometimes deer or elk will have unusual to extreme variations in antler shape, along with abnormal protrusions that appear to sprout and drop in every direction. Elk and deer with these abnormalities in their headgear are said to have “atypical” or non-typical antlers.

Brian Marsh, district wildlife manager for Colorado Parks and Wildlife, offers an explanation for this interesting phenomenon.


District Wildlife Manager Brian Marsh.
District Wildlife Manager Brian Marsh

“There are several factors that can cause non-typical or deformed antlers. One of the most common causes of nontypical antlers happens when the buck or bull damages the pedicle or base where the antlers grow. This often happens at an early age or right after the animal has shed its antlers in the spring. If a buck or bull has a damaged pedicle, the animal will likely have nontypical antlers every year.

Antlers in the velvet stage are also susceptible to becoming damaged or deformed. The velvet protects blood vessels and the soft material developing underneath that eventually becomes the hardened antler. However, if the velvet gets severely damaged, the bull or buck will likely display non-typical antler growth that season, but the antlers will grow normally the following year — if the velvet is unharmed.


Genetics also play a role in antler development. This is often the case where non-typical antlered bulls or bucks are common in a specific area.

This buck was seen near Colorado Springs in 2011. His enormous, nontypical antlers earned appreciation from wildlife watchers and hunters alike. Photo by Mike Seraphin/CPW.
This amazing buck was seen near Colorado Springs in 2011. His enormous, nontypical antlers earned appreciation from photographers, wildlife watchers and big-game hunters. Photo by Mike Seraphin/CPW.

Hormone Levels

In addition, hormone levels can also affect antler growth. Bucks or bulls with low testosterone levels often will not shed their velvet at all. Instead, They will have a large mass of velvet near the pedicle. Animals with this condition often grow points and spikes in all directions and are sometimes referred to as “sticker” bucks or bulls.


Lastly, bodily injuries can affect how antlers develop. For example, if a buck or bull has an injured leg, their antlers may become deformed or stunted. This is from the animal putting more energy into healing the injury rather than toward antler growth.

So, as you can see, there are a variety of factors that can cause nontypical antler growth in deer and elk, but each of these scenarios can make for some incredible looking antlers. These are special animals that often attract a lot of attention from hunters and wildlife watchers alike.”

Do you have a hunting, fishing or wildlife-related question for a Colorado Parks and Wildlife biologist? Submit your question to Jerry Neal (jerry.neal@state.co.us). Your question may be used in an upcoming “Ask the Biologist” segment on Colorado Outdoors Online.

4 Responses

  1. Bonnie, Thanks for your comment. Although a few deer in the Colorado Springs area have been affected by mange, is it rare and more frequent in animals like coyotes and foxes. The deer shown above appears to have normal summer hair growth and shedding, which can make the coat appear a bit rough compared to other times of the year. Typically, deer with mange have very dramatic hair loss and other visual signs that they are infected.

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