In recent installments of Happy Trails we have kicked around various aspects of both the science and art of aging whitetails on and off “the hoof.” Most deer hunters want to become as proficient as possible at estimating deer age BEFORE pulling the trigger, but it is equally important to either confirm or revise your eyeball estimate after the kill. This is where the science of jawbone aging, over time, helps to instruct and improve your eyeball skills.

As I previously pointed out, I clean, label, and preserve all the jawbones that are generated from my hunting property as a tangible data base. I then estimate the age of each jawbone using the tooth replacement and wear technique as a check on how well we are doing in our eyeball estimates before the trigger is pulled. By definition though, this activity requires jawbones. Unfortunately, some hunters just do not want to mess with jawbones and would look at it not as an opportunity, but as a bunch of hoops that they don’t want to jump through.

If you fall into that category, there is an alternative that can accomplish most of the same goals. Consider taking two quick photos of a deer’s lower jawbone and then use the photos for aging purposes. This alternative can be nearly as accurate later as physically having the jawbone in your hand. Afterward, you, or somebody actually trained in jawbone aging, can use the photos to render an age estimate. I have yet to run into a deer hunter in the field that was not carrying either a small digital camera or a cell phone with a camera.

Depending on your circumstances, taking the suggested two photos can be done in the field, at the skinning shed, or even later at the taxidermist. For consistency, I would recommend that you preselect a particular side of the lower jawbone and then stick with it. I personally always use the lower left-side jawbone, but the right-hand side would do just as well. If you have a preference the key is just to stick with it, because, unless your brain and eyes work differently from mine, comparing a right-side jawbone from one deer to the left side of another deer can be a little awkward. It is just way easier for comparison purposes if you always use the same-side jawbone.

The first photo should be taken looking straight into the cheek side of the jawbone from the side. With this view alone, the ager should be able to peg whether the deer is a fawn, a 1 ½-year-old, or at least a 2 ½-year-old by using the “tooth replacement” technique.

The second photo should be taken looking straight down on the lower jawbone. With this view an age estimator can see the relative exposure and width on the molars of the brown dentine, as compared to the exposure and width of the outer white enamel of the molars. You can either completely remove the jawbone to take this photo, or you can take it without removing the jawbone, but if the deer is a buck and a trip to the taxidermist should be in your plans, wait and have the taxidermist remove it for you. If you don’t care about the cape, just go ahead and cut through the corner of the deer’s mouth and carefully cut the flesh of the cheek away from the lower jawbone completely exposing the side view. Afterward you just open the deer’s mouth as wide as possible and take the photo. This shouldn’t take more than a few minutes total. 

This is where the “wear technique” comes into play separating deer that by “tooth replacement” are indicated to be at least 2 ½ years old, into additional categories of 2 ½, 3 ½, 4 ½ years or older. As whitetails age, they progressively expose more and more dentine on their molars, allowing for a relative segregation between adult and mature age classes. To be reasonably accurate, the tooth wear aging technique requires that one have experience in a given geographical area, looking at lots of jawbones. This is why I age, label, and keep all of my jawbones for future reference. 

Most all of us these days use trail cameras to see what deer activity is actually happening on our hunting properties. This surveillance usually starts in the pre-season, and in most cases continues right on through the hunting season. My recommendation is to take lots of photos and to label and save them digitally in some logical format. When your database contains photos of known deer that you have taken, along with their aged jawbones, your ability to age deer on the hoof improves dramatically.