Record keeping is the foundation of whitetail conservation.  Accurate harvest records are crucial to plan management goals and objectives.  After several years, trend data will develop and reveal a deer manager’s success or failures all to which will assist future management decisions.  Are your bucks growing larger antler sets or are they decreasing total inches?  Are your does breeding at younger ages or are they struggling early in life?  There are numerous whitetail data points that can be unlocked with simply saving and aging the jawbone.

 

Removing the jawbone is straightforward and can be handled within minutes.  If you drop off deer at your local processor, you can extract it from your tailgate before locking the property gate.  If you rely on a skinner at your processor, you will likely not receive it.  In fact, I started extracting caped buck jawbones myself before dropping off at the taxidermist.  I covered this method on a recent YouTube video. I grew tired of receiving maybe half of requested jawbones. 

 

I prefer a razor-sharp knife and heavy duty shears.  Use tension to filet the hide off the jaw.  From there you can easily snap off the bone right behind the last tooth with shears.  SC DNR has an excellent breakdown using a jawbone extractor which are inexpensive.  The University of Missouri has a thorough analysis of aging jawbones and it also covers the highly accurate cementum annuli technique. 

 

Weight Trends

Matching live weight with age unveils many characteristics of your local herd.  It’s imperative to utilize a precise scale and maintain meticulous records.  It’s very easy to skip the harvest log book post hunt when you’re a couple cocktails down with your crew but you can’t let it slip.  My strategy has been to give the guy who can’t skin the book to write down all the data points.  Everyone isn’t skilled behind the knife, but they can certainly write down several numbers and notes. 

 

Post season you’ll have time to pair all harvest kill stats with ages.  Over time you’ll notice trends:

 

1. Weight increase – an uptick in poundage indicates deer under carrying capacity.  Maybe you have been aggressive with antlerless deer kills and with a lower population you’re producing healthy whitetails.  Better health affects every aspect of deer that a conservationist and hunter would like to yield from management efforts.  Weight escalation can also be a sign of successful habitat and supplemental food plot programs.  Ground disturbance, prescribed fire, timber thinning and protein rich field plantings provides whitetails with high quality forage to meet nutritional demands.  
2. Weight decrease – generally, this signifies an overpopulation.  Too many deer on the landscape causes over browsing and a significant reduction in quality forage.  Deer have preferences just like you and me.  In this scenario, the best food options will be hammered early and will likely never produce seeds for the next growing season.  A skewed doe:buck ratio is another indicator of weight downturns.  Too many does will create underweight deer.  Does will produce less fawns and bucks will not fully express their antler potential.  Who wants that??!!  I would be remiss to mention a possibility of weight reductions within does.  If you consistently target the biggest doe to kill within a group, over time, you’ll remove the older age class.  The remaining doe crop will still be healthy, but you can see other side effects from this harvest method which will be covered in another article.  Stay tuned. 
3. Pregnant does – late season doe data can and will give you an edge with shoulder mount additions to your wall.  I covered this in detail from a previous article.  Pairing doe weight with the number or fetal sacks and age is one of the finest tools a deer manager has in their toolbox.  At our farm, a robust fawn doe, born on time, should hit sexual maturity within 5.5 – 6 months at an approximate weight of 75lbs.  This is an indicator of high-quality habitat and a healthy herd.  A yearling doe (1.5) that’s pregnant with twins is another sign of well managed land.  However, a 3- or 4-year-old doe pregnant with one fetal sack is not as healthy as a deer manager would prefer.  It’s not possible to target these deer for culling but it will show trends.  Knowledge you can monitor and apply for subsequent management objectives.  For instance, if my statistics indicated minimum pregnant fawns, yearlings or 2+ year olds with twins, I’d regulate antlerless deer heavily and with authority! 

 

 

Antler Trends

Understanding localized headgear expression is key to effectively manage your herd.  Years ago, I traded stories with a fellow that hunts in my county.  He claimed to have passed a 150” 2-year-old buck at 10 yards.  I’m sure he thought he did, but odds are better for Vanderbilt to win a National Championship this Fall than a 150” 2-year-old in Barnwell County, South Carolina.  Don’t get me wrong, we have large deer but that would put the buck on track to be over 200” at maturity. 

 

If the hunter understood body weight in relation to age and thus a typical antler range, he might have a better understanding as to what he saw.  It could easily have been a 4-year-old run down from the breeding season or a 135” 3-year-old.  Hunters routinely mislabel deer ages because they don’t spend time with jawbones.  They aren’t pairing live weight and antler scores with accurate aging.  This is what separates hunters from deer managers.  Designing and implementing a harvest plan for a standing buck crop is entrenched with antler expression through maturity years.  What are 3, 4, and 5-year-old trends?  What should you expect to see at 6 or 7?  Is harvest better at 5 or 6?  All these questions and many more can be unlocked when you study teeth. 

 

Culling or removing inferior bucks has been a management method for many decades.  We already know that genetics cannot be managed within wild herds.  However, we can reduce the standing crop to allow the cohorts with excellent antler expression to flourish.  This also allows mothering does to increase nutritional intake consumption and develop healthier buck fawns that will ultimately have higher antler traits to be expressed, as long as, habitat and herds remain consistent.  I cover this topic thoroughly in the latest Southeast Whitetail Podcast episode.  This method works with accurate age implementation. 

 

This year an in-depth study published by Mark Turner, Dr. Craig Harper, Dr. Bronson Strickland, Dr. Marcus Lashley, Dr. Mark Wilber and William McKinley revealed break through research correlating doe weight to antler size.  As doe weight increases, so does inches of antler.

 

I had the pleasure of hearing Mark Turner discuss this project at the Southeastern Deer Study Group meeting.  It was truly the most fascinating research project at the annual conference.  As deer managers and conservationists, record keeping is paramount for the highest level of herd management.