Age this jawbone

[pass-thru]

....from last night's buck. Killed in coastal NC.

 

[pass-thru]

One thing intersting, when I was cutting the jawbone out, there was some kind of big worm up in the cheek muscle...anybody know what it might have been?

 

[BSK]

At least 4 1/2. I would have to have the jawbone in my hand to say if it was 5 1/2.

 

[BSK]

One thing intersting, when I was cutting the jawbone out, there was some kind of big worm up in the cheek muscle...anybody know what it might have been?

Bot-fly larvea. Really ugly but do little harm.

 

[Quailman]

At least 4 1/2. I would have to have the jawbone in my hand to say if it was 5 1/2.

Agree. At least 4 1/2.

 

[Good time Charlie]

Wes could tell ya,But he is mature, would like to see the deer

 

[BigGameGuy]

"Nice" jawbone... :D

At least 4-1/2.

 

[pass-thru]

Here's a photo to show the crests. He was an average coastal buck, which are very small in antler and body. Inside spread 10.5, 14" beams, 2.5" bases. The age structure on the coast is very high. I think fawn mortality is high and mature does killed in the winter often only have one fetus. A lot of the bucks killed in the semi urban area I bowhunt on Lejeune are this old or older. I could tell he was mature by the body characterics even though not large compared to inland deer. I think 5 1/2.

 

[rtp]

From both of those views I would say 5.5. Way to bag a mature buck. Good job. If you ever want additional confirmation there are services out there that will grind the teeth down and count the growth rings like on a tree. It is more accurate than the wear method of aging but still not 100% accurate. I have used them several times on deer that were harvested but the teeth did not indicate the age I estimated prior to the deer being killed.

 

[pass-thru]

I have used them several times on deer that were harvested but the teeth did not indicate the age I estimated prior to the deer being killed.

Were they off high or low, and how many years?

I have thought about sending some in over the years...but it's fairly expensive.

 

[BSK]

pass-thru,

After seeing the side view, I would agree that buck is 5 1/2.

 

[rtp]

I have used them several times on deer that were harvested but the teeth did not indicate the age I estimated prior to the deer being killed.

Were they off high or low, and how many years?

I have thought about sending some in over the years...but it's fairly expensive.

Pass thru, Each time the tooth wear looked younger than what I had estimated on the hoof. Each time I sent in for an analysis, it came back to match the age I had estimated on the hoof. The first instance was a buck that one of my hunters took the last weekend of the season. After seeing video of him I called him 5.5 and told the hunter to take him if he wanted and he did later in the hunt. It was a 9 point with one or two kicker points if I remember right that scored in the low 140s. When I removed the jaw bone I could not believe what I was seeing. The teeth were almost razor sharp showing very little if any wear, like you would see on a 3.5 yr old. It really bothered me to have made that big of a mistake. I mean a 3.5 yr old with a 140s rack definitely gets a 2 year walk on my place. I finally decided to send the teeth in for analysis and once I got the report back indicating 5.5, I felt better that we had taken a mature deer. If you are not in a hurry to get the results back, I think the test is $20 or $25 buck. Not sure if we can post websites so I will PM you the place I have used. Again, congrats on taking a mature buck. To me that is what it is all about.

 

[BSK]

Just remember that cementum annuli is NOT accurate. It has no greater accuracy than tooth wear.

 

[PickettSFHunter]

Just remember that cementum annuli is NOT accurate. It has no greater accuracy than tooth wear.

You disagree with Montana Fish and Wildlife's study? 85% accuracy for whitetails through 9 years old with cementum annuli, 42.9% for whitetails using tooth wear. All research Ive seen by professionals in the field says cementum annuli is better for aging deer 3 1/2 and up. Just seems like quite a statement to make. Do you have research to back it up?

 

[rtp]

Well, the way I look at it is that there are three methods for aging a deer. One is looking at the physical characteristics of the animal while alive, another would be tooth wear and the third cementum annuli. So if I can get at least two of the three to agree then I feel safe that the age I am recording is fairly accurate. That is why I only send in a tooth to have it aged by cementum annuli if my visual estimate conflicts with what the tooth wear says. This will never be an exact science but a best guess estimate. The biologist I have dealt with here in Texas have indicated to me that tooth wear estimates are about 65% accurate and the tooth cementum annuli method is about 85% accurate. Now I was not given any age parameters with these numbers so that may account for the differences.

 

[BSK]

Just remember that cementum annuli is NOT accurate. It has no greater accuracy than tooth wear.

You disagree with Montana Fish and Wildlife's study?

Not for Montana. Northern deer show good accuracy with cementum annuli because they do not have two stress periods per year. Southern deer often have two stress periods per year (in some years) which throws off the cementum annuli aging process. They are looking at the rings of calcium deposition on the teeth, with the stress periods producing the narrower bands used for finding a single year of growth. If there are two stress periods in a year it will appear to be two years instead of one.

Hellickson's study in TX found poor accuracy from cementum annuli because TX can have multiple stress periods per year. The Southeast is notorious for a late summer stress period.

For TN deer, I would place no extra accuracy on cementum annuli aging because of our propensity for late summer droughts. In fact, with tooth-wear, at least you know you have an accurate minimum age (although NOT an accurate maximum age).

 

[pass-thru]

There are a lot of known age deer out there. I would very much appreciate it if somebody would publish a collection of jawbones from known age deer that fed on a normal diet from whereever they lived. It would be interesting to see for sure variations among age groups from actual deer.

I've got a whole box of jawbones from the VA DMAP program aged by their biologists through 8+. I think in reality the differences among age groups is much more subtle than the milestones used for teeth wear.

Having known age reference would help sort through some of theses sublties, especially if from the same region.

 

[TheLBLman]

At first inspection, this one appears AT LEAST 4 1/2, but could not say 5 1/2 or older.

HOWEVER, considering this deer was killed in early September,
I would say 5 1/2 or older as a best guess.

 

[TheLBLman]

Pass-thru,

The "best of the best" jawbone agers are merely "guessing" even with the bone in hand. That buck could have been 4 1/2, he could have been 6 1/2 (maybe older) ---- just my best "guess" he was 5 1/2.

My take is individual bucks have different tooth wear rates just like individual people. Ever see a young fellow with rotten teeth, or an old fellow with good teeth?

Regional differences, diet differences, and varying wear rate differences of individual deer will prevent us ever having anything more than a good "guess".

If you're not looking at the jawbone, you're just guessing.
If you are looking at the jawbone, you're still just guessing.
But we can guess reasonably accurate out to 4 1/2 or 5 1/2, seldom missing by more than 1 year, i.e. good enough to provide great trend data.

 

[TheLBLman]

Hellickson's study in TX found poor accuracy from cementum annuli because TX can have multiple stress periods per year. The Southeast is notorious for a late summer stress period.

For TN deer, I would place no extra accuracy on cementum annuli aging because of our propensity for late summer droughts. In fact, with tooth-wear, at least you know you have an accurate minimum age (although NOT an accurate maximum age).

And I totally agree with Hellickson, Kinkel, et al. ;)

Add another factor that can sometimes make the cementum annuli method grossly less accurate:
Human Error.
Like mislabling one jawbone for another.

In a perfect world, the cementum annuli SHOULD be more accurate.
But we humans tend to make lots of errors.

I figure out to 5 1/2 we seldom miss by more than 1 year, although it's not uncommon for a known 7 1/2 to be aged as a 5 1/2 by professional jawbone agers. ;)
But that sure beats sending off a known 7 1/2 to a lab and it coming back with a mis-label saying "2 1/2".

 

[rtp]

So then do you think that for an experienced person, aging on the hoof is just as accurate as either of the tooth methods?

 

[BSK]

So then do you think that for an experienced person, aging on the hoof is just as accurate as either of the tooth methods?

There was a recent field-judging study that found most human judgers were not very accurate. However, I have some real problems with they way that study was conducted (I don't think it was a well-designed study).

But of interest, one the prime methods I use to field-judge age was found by this research project to be the only scientifically viable way of determining age by body conformation, and that method is measuring the depth of the shoulder/chest in comparison to the visual length of the front legs. Basically the ratio of shoulder-chest depth to leg-length below the brisket.

In addition, I'll be the first to tell you that deer from different regions have different body conformation at the same age. For instance, TX deer will look younger than TN deer. On the other hand, northern deer will look older than TN deer. And I can't age a coastal deer to save my life. A fully mature coastal deer will look like a TN 3 1/2 year-old. A person can learn to be highly accurate with their regional deer, but may run into problems when judging deer from other regions.

I keep track of bucks I've aged from trail-camera pictures that are later harvested by hunters and tooth-wear age determined. Over numerous years of data collection, I'm running around 80% accuracy with my field-judged ages matching tooth-wear. But again, we assign age based on tooth-wear, and tooth-wear won't produce accurate maximum age on mature bucks. Tooth-wear is very good at assigning minimum ages but not maximum ages on bucks 4 1/2+. But with the field-judging process, body conformation is linked to tooth-wear age. In essence, for bucks with "X" amount of tooth-wear, they will display "Y" body characteristics. If the "X" tooth-wear ages are not accurate...

 

[Andy S.]

I keep track of bucks I've aged from trail-camera pictures that are later harvested by hunters and tooth-wear age determined.

Bryan,

Were all or most of these bucks aged Oct/Nov timeframe when you assigned your "field judged" age? Reason I ask is if the bucks were chosen during this timeframe I would expect a lot more accurate field judging results versus deer chosen in late summer or post rut.

Over numerous years of data collection, I'm running around 80% accuracy with my field-judged ages matching tooth-wear.

For the other 20%, did you tend to over age or under age the deer (field judged age) based on tooth wear? Or was it a little of both?

 

[BSK]

I keep track of bucks I've aged from trail-camera pictures that are later harvested by hunters and tooth-wear age determined.

Bryan,

Were all or most of these bucks aged Oct/Nov timeframe when you assigned your "field judged" age? Reason I ask is if the bucks were chosen during this timeframe I would expect a lot more accurate field judging results versus deer chosen in late summer or post rut.

Correct. The most accuate field-judged ages will come from bucks in October and November, because that is time-frame for which field-judged age criteria were developed.

Over numerous years of data collection, I'm running around 80% accuracy with my field-judged ages matching tooth-wear.

For the other 20%, did you tend to over age or under age the deer (field judged age) based on tooth wear? Or was it a little of both?

50/50 mixture of both. However, it is rare that I miss it by more than one year. In fact, the grand total of those occurances is 2; with one 2 1/2 year-old buck judged as 4 1/2, and one 4 1/2 year-old buck judged as 2 1/2.

In fact, here they are:


This pig-bodied buck I judged to be mature (4 1/2) turned out to be only 2 1/2.

This scrawny 5-point that I judged to be 2 1/2 turned out to be 4 1/2.

 

[Andy S.]

In fact, the grand total of those occurances is 2; with one 2 1/2 year-old buck judged as 4 1/2, and one 4 1/2 year-old buck judged as 2 1/2.

Thanks for the explanation. I have grossly miss judged a few in the past that hurt my "field judging" confidence. The one I remember most was a massive body deer I shot a few years back for a 4.5 year old only to have his teeth indicate 2.5. He dressed 187 lbs and had a 25" or so neck. That really set me back a few steps as far as shooting based on my field judging ability. It's nice to see others "sometimes" err as well. I just thought my error judgment was absurd considering I missed him by two years, and to add to that I overaged him on the hoof, which is the last thing I wanted to do considering we are trying to protect all 2.5 year olds.

Another question here: With the number of bucks missed being 2 representing 20% of your sample set, does this mean the total sample set over the years equal 10 (N=10)? If my thinking is correct, this would mean the other 80% that were "field judge aged" correctly based on "tooth wear" totaled 8 deer. Is this correct?

 

[rtp]

I have found that I am super accurate on my deer herd when aging on the hoof vs what the tooth wear shows. I have only missed 3 over the last 4 yrs and we avg 18 bucks per year. Of those 3, 2 were sent off for analysis and the ring count matched what I called for. I have been hunting on this ranch for 15 yrs and on a normal year will get to see around 150 to 200 bucks so I have had lots of practice on this land. With that said, while I feel very confident in calling deer age on my place, I become very uncomfortable and less confident when I venture off to other places. Sure there are obvious and easy to call deer on every ranch but those tweeners really get me when I'm on someone else's place. I cant even imagine trying to go out of state and feel confident aging a deer. When I watch some of those TV shows where they are hunting up north, I see deer I think are mature and the host will say it is a 3.5 yr old. Yikes.

I would agree with the top of the shoulder to the bottom of the chest distance vs. the leg length. When I am having trouble aging a certain deer, I find this is the one element I always fall back on to make my final call. I guess it is all just a guess. As long as we are trying to take mature deer it doesnt matter if we make a mistake here and there because mother nature is going to take out more young bucks than we ever will. Bow season starts for us on Oct 2, I cant wait.

 

[Andy S.]

Another question here: With the number of bucks missed being 2 representing 20% of your sample set, does this mean the total sample set over the years equal 10 (N=10)? If my thinking is correct, this would mean the other 80% that were "field judge aged" correctly based on "tooth wear" totaled 8 deer. Is this correct?

Disregard this question as I re-read your post and answered it myself. Your grand total for missing it by more than a year is 2, not your grand total that you have ever missed. ;)

With that being said, what is "N" value for your 80% correct and 20% missed? Just wondering how large the sample set is that you have verified with tooth wear?

 

[rtp]

BSK, I would have surely called that deer in the first pic much older than 2 1/2. He was truly out of the normal bell curve to have that kind of body and only be 2.5. Too bad we can't put them in the dentist chair for verification before we shoot! :eek:

I know some of these deer in Texas that have been eating mostly protein pellets their entire lives show much slower tooth wear than a deer on the open range. Thus they can live longer and produce bigger antlers longer at older ages.

 

[spoon]

My be reaching on this, but if it's coastal area or Texas, can sand cause more wear and throw the age off?

 

[rtp]

I have heard that deer inhabiting sandy soil areas teeth will wear faster than most. Not sure there are any studies to prove this, just what I have heard from some wildlife managers here in south Texas.