Pooling Jaw bones, a more precise aging tool (Episode 9 Transcript)
This is the video transcript. To watch the video for this episode click here.
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WOODS: Deer Number 31 is six and a half plus.
COREY: 6.5 plus on 31.
WOODS: Deer Number 18, six and a half plus.
WOODS: Corey and I are on a project in west central Georgia. It’s towards the end of the season. We’re gonna harvest maybe a dozen more deer at the very most. And while I’m in town we’re gonna go ahead and pool jaw bones.
Pooling jaw bones is a technique that we simply age jaw bones, one at a time during the season when we’re harvesting deer and processing deer. And each jaw is tagged and labeled with the date and other information we need. And we put them in our jaw bone basket. It’s late. It’s about supper time. You know, we say, “Two and a half or three and a half or four and half.” Throw them in a jaw bone box.
But at the end of the year, we take them all out and we lay them where we can compare this jaw bone to this to this to this and we can compare dozens of jaw bones and say, “Wait a minute. This doesn’t look anything like the rest of the pile of the two and a half year olds. It looks older. We need to move it to the three.” So, we’re pooling the age classes. Hence the name. And it gives us a more accurate estimate of the age. And really accuracy is not the right term. It gives us a more precise estimate.
COREY: So we, we’ve taken all of the jaw bones and laid them here on the table and we’ll mix them all up so that we don’t have any preconceived notions of what we think each one of these jaw bones has already been aged at. And then we’ll take them and go through each jawbone and separate it out on the table and, and group them by age class. So, we’ll have the one and a half year-old age class here; two and a half; three and a half and so on.
And, uh, what, one of the things that, that this really helps with is that it sort of takes away that preconceived notion of when you're looking at the deer, especially if it’s a buck and you're looking at the antler size of this buck or the body size and, and you already have in your mind that, “Hey, this deer is gonna be five years old.” Well, we can come back and look at this jawbone in the absence of, of that influence and then get a more accurate age of what the jawbone said.
WOODS: We’re more precise over time. And we have figured out over 11 years on this project, we change our estimates on about 20% of the jaws. For example, we may have called a two year old, but when we put them all together, it’s just a three or vice versa. And a 20% shift is really big when we’re looking at, “What’s our average two year-old deer weigh? What’s our average three year-old deer weigh?”
WOODS: And how this all came to be is: years ago when I was in graduate school, we took 20 known age deer that were tagged as fawn or raised in pens. Separated the jawbones and at a meeting called the Southeast Deer Study Group, we had several known good deer biologists come by and age them. And they were about 40% more accurate when we pooled the jawbones. Put them out in age, in a group and age classes, then whether we just had them in random like you would when you harvest. And when we got young deer and the next guy says, “I killed an old deer,” or whatever. So that’s where the pooling technique came from is that paper at the Deer Study Group. And Corey has even refined it a little bit more here and we hope you can use this on your club to become better deer managers.