joe hamilton qdma aging white-tailed deer by tooth eruption and wear
TRANSCRIPT
Joe HamiltonQDMA
Aging White-tailed Deer by Tooth Eruption and Wear
Why Age Deer?
• To allow comparisons within sex and age classes
• To determine appropriate harvest strategies
• To track progress of management efforts
Both of these bucks are 8-pointers, but without knowing their age, you can’t compare them
Jawbone Removal
Anatomy of a Jawbone
Back
Buccal Crests (cheek side)
Front
Lingual Crests (tongue side) Incisors
Back Cusp
Anatomy of a Jawbone
Dentine(dark)
Enamel(white)
PremolarsMolars
P1P3
P2M1M2
M3
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.
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.
Tooth Wear
1 ½
3 ½
5 ½
Dentine (dark)
Enamel (white)
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
Aging – Step 1
Separate Into Three Age Classes
1. Fawn (6 months)- three or four total jaw teeth
2. Yearling (1 ½ years old)- six teeth, but temporary third premolar (P3)
3. Adult (2 ½ years old) -six teeth, but all permanent
Temporary premolar (three crests)
Permanent premolar (one crest)
Temporary vs. Permanent Premolars
Separating Deer Into Three Age Classes
Yearling
Adult
FawnP1P2P3M1
P1P2P3M1
P1P2P3M1
M3M2
M2M3
Fawn (6 months old)
Key – Only 3 or 4 fully erupted teeth
Yearling (1 ½ years old)
Generally fully erupted
Note permanent tooth erupting, may already have replaced temporary tooth if harvested late in season
Keys – 6 teeth and temporary 3rd premolar
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.
Question - Is the dentine (dark) on the lingual crests approximately twice as wide or wider than one strip of surrounding enamel (white)?
YesNo
2 ½ years old
Keys – six teeth, permanent 3rd premolar (P3) and dentine not twice as wide as surrounding enamel on the first molar (M1)
M1
No
P3
3 ½ years old
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.
M1M2
Yes No
4 ½ years old
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.”
M1M2
Yes Yes No
M3
5 ½ - 6 ½ years old
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.
M1M2
Yes Yes
M3
Yes
7 ½ + years old
9 ½ + years old?
Next time you harvest a deer, give aging a try!