Extra main beams are an uncommon bonus.
QUESTION: What are the odds of a whitetail having an extra beam? In the past several seasons, we have seen or have pictures of three different bucks with extra beams. One has a whole additional beam and tines, while the other two just have an extra beam. One is a 10-pointer, and the other is an 8-pointer.
ANSWER: I don’t know what the odds are, but extra beams are extremely rare and most often the result of an injury, either to the antlers or the long bones of the legs.
An interesting side note: Injury to a leg bone often results in a malformed antler on the opposite side. Abnormalities like extra points or beams are also more likely to occur on older deer.
Given that you’ve observed multiple bucks with this abnormality in the same area, it’s more likely in your situation that it’s the result of genetics. That makes it even more rare, and as you’ve observed it on different sides, rarer still.
— Recent Ask the Biologist Question: Fool Me Once : We know deer respond to hunting pressure, but what about wounds? Find Out The Answer!