QUESTION: Bob, I would like to know what causes the bumpy area on the bases of a buck's antlers. Isn't that known as the burr of the antler?
It reminds me of the base of a tree. What causes that gnarly texture, and what determines how far up it grows on the antlers? - Garlan W.
ANSWER: If there were a prize for the most challenging question I've ever received, you'd be the winner!
I must admit I didn't know the answer, so I did some research and found absolutely nothing on this specific topic.
This much we do know: The very base of the antler, immediately above the point of attachment (the pedicel) is called the burr.
Just above this you will find varying amounts of texture referred to as perlation.
Antler growth is triggered by photoperiodism (change in length-of-day). Through a series of physiological changes, testosterone levels rise, stimulating the growth. The initial growth of antlers begins as cartilage. Through a process called ossification, minerals replace the cartilage. The minerals are carried in microscopic form through the circulatory system into the growing antlers, which later becomes bone.
This process begins at the base and progresses outward and upward in the form of tines. So while the tips are still growing, the base is becoming increasingly more mineralized.
As to what actually causes perlation, the best answer I can offer is some knowledgeable speculation.
Toward the end of summer, antler growth slows, and the living, growing tissue begins to break down. This includes the circulatory system that carries minerals to the antler tips.
As this system is compromised, it's possible that excess minerals are shunted, and begin building up at the bases.
At this point it's worth noting, perlation is more common in older deer. Once a buck reaches maturity at age four, its skeleton stops growing. This means relatively more minerals are available for antler growth, which could partially explain the increased texture.
I'd also be curious to see if there's any correlation between the degree of perlation and the amount of minerals in a deer's diet.
It's also worth noting that the beads or perlations are usually little more than tiny, rounded nubs, but sometimes grow larger, becoming sticker points around the bases.
An extreme example is a non-typical formation sometimes referred to as a "cactus" buck.
This leads me to further speculate that some perlations have the potential to become measurable points, given the right conditions.
If anyone has any further information on the subject, I'd love to hear from you. Meanwhile, that's my story, and I'm sticking to it.