|
Whitetail
Ageing
How to Age Deer?
Whitetail deer are primarily
born in late May and early June. Therefore, when most deer are harvested in
November they are either six months, 1-1/2; years, 2-1/2; years, 3-1/2;
years, etc., in age. This guide is designed to block deer into these age
categories. The overall age structure of a hunted deer population is younger
than most people think. There are some states that the average harvested
deer’s age is 1-1/2 years old. Antler and body size can indicate a deer's
age, but physical characteristics are often misleading. The number of
antler points in no way corresponds to age. Even if it did, it wouldn't
help in aging does, which make up a considerable proportion of the harvest
each year. Antler size in bucks and physical development in both genders is
greatly affected by diet and genetics, which may account for differences
between animals of the same age taken from different locations. The only true
way to measure age is by a deer’s teeth.The science of aging deer is based on
tooth development and wear. Like humans, deer replace their "baby
teeth" with permanent teeth at a relatively set rate. As surely as a
6-year-old child will soon lose her two front teeth, an 18-month-old buck
will be in the process of losing its third premolar. By the time a deer is
2-1/2; years old, all permanent teeth are in. At this stage, estimating age
is based largely on the rate of tooth wear. Diet and soil types may
accelerate tooth wear, but generally, estimating the age of adult deer is
straight forward until they reach age 5-1/2;. Beyond that, estimating age by
tooth wear is less reliable.
Tooth Identification Basics
Whitetail and mule deer
basically have two groups of teeth. The front teeth, or incisors, are used
for collecting food. The back teeth or cheek teeth - molars and premolars -
are used to chew and grind food. Between the incisors and molars is an open
space along the jaw that has no teeth. (Note: In all photos, black line
indicates the gum line.)
Front Teeth (Inisors):
These
are the front teeth on a deer jaw. When a deer is 5-6 months old, the central
two incisors are replaced. The rest of the front teeth -lateral incisors and
canine teeth - are replaced during the 10th and 11th month. Unlike horses,
deer do not have upper incisors.
  
Cheek Teeth
Premolars: The first
three teeth on each side of the jaw are called premolars. Deer grow two sets
of premolars. The first set appear in fawns and last until the deer is about 1-1/2;
years old, when permanent adult premolars push out the baby premolar teeth.
An important characteristic of the first set of premolars is that the third
premolar has three crowns or cusps. When the permanent teeth
come, all premolars have just two cusps.
Molars: The
fourth, fifth, and sixth cheek teeth are the molars. Deer only grow one set
of molars. Generally, six-month-old deer have only one molar when they enter
the fall hunting season. Therefore, six-month-old deer usually have only four
cheek teeth. By 1-1/2; years of age - the second fall - the second and third
molar have erupted through the gum, though the last cusp of the third molar
may still be below the gum line. All six molars and premolars are fully
erupted by 2-1/2; years.
The vast majority of deer
in North Dakota are 2-1/2; years old or younger. To determine the age of
animals in older age classes we need to look more closely at tooth wear.
 
Tooth
Identification Wear Characteristics
While it is possible to
determine whether a deer is a fawn by looking at its incisors or front teeth,
it is the cheek teeth, specifically those of the lower jaw, that harbor the
most reliable clues. To get a good look at the cheek teeth (premolars and
molars), you need to cut back the lip and cheek skin. If you plan to have the
head mounted, let your taxidermist skin out the head and remove the jaw for
you.
Six Months:
The nose or muzzle of the deer
appears short or stubby, when compared to older deer. The central two
incisors may still be erupting. Incisors may appear twisted as they emerge
through the gum. Generally, there are only four cheek teeth showing. The
third premolar has three cusps.
1-1/2; Years:
All permanent front teeth are
in. Six cheek teeth are visible in the lower jaw. The third premolar may
still have three cusps, or the permanent third premolar may now be in (two
cusps). Third molar may still be erupting through the gum. Lingual crest of
molars have sharp points.Inset: Extremely worn third premolar may fool
people into thinking deer is older. Actually, this tooth is lost after 1-1/2;
years and replaced with a permanent two-cusped premolar.
 
2-1/2; Years:
All permanent premolars and
molars are in place. Look closely at the fourth cheek tooth (first molar).
The cusps are sharp and show little or no wear; enamel (white portion) of the
lingual crest shows well above the dentine (brown portion). The enamel
portion of the cusp is wider than the dentine. Some wear on third cusp of
sixth cheek tooth (third molar).
3-1/2; Years:
Lingual
crests of cheek teeth show some wear and cusps are starting to become blunt.
Dentine now thicker than enamel on cusp of fourth cheek tooth (first molar).
Dentine of fifth cheek tooth (second molar) usually not as wide as enamel.
Last cusp of sixth cheek tooth is flattened.
4-1/2; Years:
Lingual crest of fourth cheek
tooth (first molar) is gone. Crest of cusps on fifth and sixth cheek teeth
(second and third molar) are blunt. Dentine of fourth cheek tooth now twice
as wide as enamel. Dentine of fifth cheek tooth wider than enamel.
5-1/2; Years and Older:
In most hunted deer populations,
less than two percent of the animals are more than five years of age.
Accurately aging these deer by tooth wear is usually more of a guessing game
than a science. In general, deer close to 5-1/2; years of age will show
considerable wear on the premolars, and the first cusp of the fourth cheek
tooth (first molar) will be dished out or show signs of "cupping."
9-1/2; Years:
By 9-1/2; years, all cheek teeth
are cupped and worn nearly to the gum line.
|