Joe Hamilton QDMA

1. Aging White-tailed Deer by Tooth Eruption and Wear Joe Hamilton QDMA

2. Why Age Deer? • To allow comparisons within sex and age classes • To determine • appropriate • harvest strategies • To track progress of • management efforts

3. Both of these bucks are 8-pointers, but without knowing their age, you can’t compare them

4. Jawbone Removal

5. Anatomy of a Jawbone Back Front Lingual Crests (tongue side) Back Cusp Incisors Buccal Crests (cheek side)

6. Anatomy of a Jawbone Dentine (dark) Enamel (white) P1 P2 P3 M1 M2 M3 Premolars Molars

7. Tooth Eruption and Wear Technique Based on two processes: 1. Tooth eruption is the process of gaining additional teeth over time and replacing temporary teeth with permanent ones. 2. Tooth Wear – is the process of tooth erosion over time with age.

8. Tooth Eruption Whitetails are born with three temporary teeth (premolars). From this age until they are about 18-20 months old, they replace these temporary teeth with permanent teeth and also gain three additional permanent molars. All whitetails 18 months of age or older should have six permanent teeth on each side of their lower jaw.

9. Tooth Wear Enamel (white) 1 ½ Dentine (dark) 3 ½ 5 ½

10. Tooth Eruption and Wear Technique • Advantages • Requires no specialized equipment, costs nothing, and can be done at camp • Can be learned by most deer hunters and managers with sufficient practice • Disadvantages • More subjective and highly dependant upon ability of individual ager • Believed to be somewhat affected by soil and habitat quality

11. Aging – Step 1 Separate Into Three Age Classes • Fawn (6 months) • - three or four total jaw teeth • 2. Yearling (1 ½ years old) • - six teeth, but temporary third premolar (P3) • Adult (2 ½ years old) • -six teeth, but all permanent

12. Temporary vs. Permanent Premolars Permanent premolar (one crest) Temporary premolar (three crests)

13. Separating Deer Into Three Age Classes Adult M3 P1 P2 M2 P3 M1 Yearling P1 M3 P2 M2 P3 M1 Fawn P1 P2 P3 M1

14. Fawn (6 months old) Key – Only 3 or 4 fully erupted teeth

15. Yearling (1 ½ years old) Keys – 6 teeth and temporary 3rd premolar Generally fully erupted Note permanent tooth erupting, may already have replaced temporary tooth if harvested late in season

16. Aging – Step 2 Estimating Age of Adults Based on Wear This technique is based on the width of the dentine on the molars compared to the width of the surrounding enamel.

17. Question - Is the dentine (dark) on the lingual crests approximately twice as wide or wider than one strip of surrounding enamel (white)? No Yes

18. 2 ½ years old No P3 M1 Keys – six teeth, permanent 3rd premolar (P3) and dentine not twice as wide as surrounding enamel on the first molar (M1)

19. 3 ½ years old No Yes M2 M1 Keys – The dentine is twice as wide as the surrounding enamel on first molar (M1) but not the second molar (M2). The back cusp is starting to show noticeable wear.

20. 4 ½ years old No Yes Yes M3 M1 M2 Keys – The dentine is twice as wide as the surrounding enamel on the first and second molars (M1 & M2) but not the third (M3). The back cusp is also starting to form a “cup.”

21. 5 ½ - 6 ½ years old Yes Yes Yes M3 M1 M2 Keys – The dentine is twice as wide as the surrounding enamel on the first, second and third molars (M1, M2 & M3). The back cusp is heavily cupped and slanting.

22. 7 ½ + years old 9 ½ + years old?

23. Next time you harvest a deer, give aging a try!