The typical “unicorn” tine–third beam that sprouts out a buck’s forehead—is 1 to 4 inches long. The middle tine in this picture appears to be 13 inches or longer, likely making it longest unicorn tine ever on a whitetail.
Biologists note that a unicorn tine is caused by trauma to the frontal bone on a buck’s forehead. This entire region of the skull is capable of growing antler, and if an area of the frontal bone is injured (such as a tine puncture from another buck) the trauma may cause a third antler to grow from the injury.
How rare is a unicorn buck? Short answer, very.
Noted whitetail scientist Mickey Hellickson says that during his days of researching wild whitetails on the King Ranch in Texas, he and his team captured more than 4,000 different bucks, and not one was a unicorn!