November 30, 2022
Query: I learn Dr. Dave Samuel’s clarification of why “Slingshot,” the buck in Curt Wells’ October 2022 article had an additional antler protruding of his brow. Might Dave clarify how droptines and double primary beams happen in whitetails? Craig S., by way of e-mail
Reply: There is no such thing as a query that older bucks are likely to develop droptines extra readily than younger bucks, and normally genetics is concerned. The genes for droptines (and sticker factors and additional factors) are typically expressed when bucks grow old. The truth that we don’t see many bucks with droptines within the wild is as a result of we kill numerous youthful bucks earlier than they’ll manifest their full potential. Some biologists imagine that just about half of all bucks have some genes for nontypical factors that will change into seen if the bucks lived lengthy sufficient. Proving this could be tough, nevertheless it certain seems to be true.
One other issue that complicates the affect of genetics on droptines is the doe. Her genes most actually play a task right here, and a few have steered that her function is much more necessary than that of the buck. Once more, that will be laborious to show, however deer-game farmers hold observe of all their breeders — bucks and does. And so they can and do breed for giant, older nontypical bucks as a result of such bucks usher in more cash.
The trigger for double primary beams is one thing completely totally different, as a result of genetics will not be concerned. Nearly actually, a double primary beam is attributable to an harm to the pedicle. Let me assessment what Curt wrote in his article in our October subject. The pedicle is the bony projection of the frontal bone the place the antler develops. It has a particular cell layer on it the place the brand new antler grows. Analysis has proven that in the event you take a few of these particular cells and transfer them, a brand new antler tine typically develops. Actually, years in the past a researcher in Canada grafted a few of these cells on the leg bone of a deer, and an antler tine grew there. Within the case of “Slingshot,” these cells moved to the middle of the frontal bone — yielding a “unicorn” buck.
However for double antlers, the cells transfer simply as a brand new antler is beginning to develop. At the moment, if the buck bumps that space of his head, he could displace a few of these cells proper beside the bottom of the pedicle. When that occurs, a second antler could begin to develop there. In the event you have a look at photographs of greenbacks with a double primary beam, that second antler’s base is correct beside or towards the pedicle. When these particular cells find yourself on the base of the pedicle, chances are you’ll not get a second antler. There are occasions when the pedicle is bumped simply because the antler begins to develop, during which case you simply get a jumble of smaller tines across the base of the unique antler. However on uncommon events, you’ll get an entire new antler.
Such bucks usually are not genetically inferior; they only have an additional antler. It is going to shed when the traditional antlers shed. And it’ll almost certainly develop there the subsequent yr as a result of the specialised cells that kind the spot the place the antler grows are nonetheless there.
The trauma to the pedicle, simply because the antler begins to develop, may be attributable to most something. The buck could bump his head on a tree limb or by sparring with one other buck. Rising antlers are topic to wreck that impacts the ensuing antler, and double primary beams is one such end result.