Aging on
the Hoof
December 2008
Kip
Adams, QDMA Director of Education and Outreach, Northern
Region
Harvesting white-tailed bucks
based on age is becoming an increasingly common management
strategy. To implement this practice, hunters must
have the ability to accurately age bucks on the hoof based
on their body characteristics, an ability that most hunters
considered impossible a decade ago. Today however,
hunters across the whitetail’s range are estimating
the age of bucks in the field as a means for selective
harvest within Quality Deer Management programs or merely
for the fun of it.
Like humans, whitetails possess distinct body
characteristics by age class, and with a little practice
hunters and nonhunters alike can become proficient at
estimating the age of bucks on the hoof. There are
many good reference books, videos and DVDs available for
in-depth instruction and practice on aging bucks, and this
article serves to introduce the topic and highlight the
differences for each age class from fawns to post-mature
animals. These body characteristics are subject to
differing interpretation by different viewers, but the
characteristics are relative to others in your area or
region. Body characteristics also change by
season. The breeding season is the best time of year
to age bucks because of pronounced neck swelling and tarsal
staining. You can estimate their age at other times
of the year, but many characteristics are viewed relative
to what they will (or did) look like during the rut.
Fawns
Fawns are easily distinguished from other age classes of
bucks but are commonly misidentified as female deer.
Buck fawns have small square bodies, small short heads and
relatively large ears. Their heads are flatter
between the ears rather than rounded like that of a
doe. The distance from their ear to eye is also
approximately the same as the distance from their eye to
nose. In contrast, the distance from an adult
doe’s ear to eye is much shorter than from its eye to
nose. Fawns also have short necks, flatter bellies
and backs, and less muscle definition than adult does. The
Quality Deer Management Association (QDMA) has produced an
educational poster, “Identifying Antlerless
Deer,” that uses close-up photography of live deer to
help you learn to sort fawns from adult does and buck fawns
from doe fawns using these characteristics. This makes a
great visual tool for teaching hunting-club members or
guests how to avoid harvesting buck fawns.
1½ years
For most QDM programs, especially those in beginning
stages, learning to identify yearling bucks is the most
important aging skill. Yearling bucks have long legs, a
thin neck, a slim body and an overall lanky
appearance. Their legs appear too long for their
bodies because their torsos (stomach, chest and neck) are
not fully developed. Their antler spread is nearly always
less than the width of their ears when their ears are in an
alert position. They have a distinct line of
separation between their neck and shoulders and little
muscle definition. They have a thin waist, and they
may have slight staining in their tarsal glands during the
rut. Overall, a yearling buck can be said to look like a
doe with antlers. In well-managed populations on
high-quality-habitat, yearling bucks can have large bodies
and even 10 or more antler points, but the above
characteristics will be present and can be used to separate
them from 2½-year-olds. This is why it is important to
study body characteristics before considering antler size
when attempting to age a buck in the field.
2½ years
Two-year-olds have legs that still appear too long for
their bodies, and they still have an overall sleek
appearance. They have developed some muscling in
their shoulders and slight swelling in their neck during
the rut, but their waist is still thin. Given
adequate nutrition, their antler spread can be equal to or
wider than their ears. Finally, they can have
moderate staining in their tarsal glands during the rut,
especially if few mature bucks are in the population.
3½ years
Three-year-olds have legs that appear to be the right
length for their bodies because their torsos are now more
fully developed. They have muscled shoulders and a
highly swelled neck during the rut, but their waist is
still lean. I liken three-year-olds to middle
linebackers as they are big and strong but they’re
also lean and fast. A deep chest and lean waist give
them a “racehorse” appearance. Their
antler spread can be even with or wider than their ears.
Research shows that at this age, most bucks have achieved
50 to 75 percent of their antler-growth potential.
They also have a lot of tarsal staining during the rut.
Beyond 3½ years of age, determining the exact age of a buck
becomes more difficult because of increased variation among
individual bucks. However, for most QDM programs, harvest
goals can be achieved if hunters are able to confidently
separate bucks into one of three groups: A) Yearlings, B)
2½-year-olds, and C) 3½ or older. Hunters who want to sort
and select bucks based on ages older than 3½ can still do
so, but more time spent studying each buck may be required.
In addition to viewing in the field, use trail-camera
photos and home-video footage to refine your estimates.
Also, once a buck has been harvested, check your own field
estimates against age estimates based on toothwear and/or
cementum annuli ages from a reputable lab. This will help
you hone your skills at aging the deer in your region or
habitat type.
4½ years
Because their stomachs, chests and necks are now fully
developed, most four-year-olds have legs that appear too
short for their body. They have fully-muscled
shoulders, heavy swelling in their neck during the rut, and
their waist has dropped down to become even with their
chest. Given adequate nutrition they’ll become
structurally mature and can reach 75 to 90 percent of their
antler growth potential. They also have a lot of
tarsal staining and during the rut the stain may extend
below the tarsal gland. Four-year-olds have an
entirely different appearance than one- to three-year-old
bucks.
5½ to 7½ years
Other than in select places, few free-ranging bucks exceed
five years of age so I’ll combine five- to
seven-year-olds. Bucks in this category have legs
that appear too short for their body. They also have
several other characteristics of four year olds including
fully-muscled shoulders, heavy swelling in their neck
during the rut, and a waist that’s even with their
chest. However, they also may have a pot belly and a
sagging back. Their increased body mass gives them a
more rounded appearance, and they may look like a small
cow. They will have achieved 90 to 100% of their
antler growth potential, and they can have highly stained
tarsal glands during the rut, with the stain extending well
below the tarsal gland.
8½ and older
A few free-ranging bucks make it to the post-mature age
category. These bucks have passed their prime and
regress in both body and antler size. They generally
have loose skin on their face, neck and shoulders –
usually visible as a “chin flap” – and
they may have pointed shoulder and hip bones. Their
antlers can show age-related abnormalities such as abnormal
points or wavy or curvy tines, and they have an overall
“weathered” appearance.
As you study age-specific body characteristics you’ll
notice there aren’t age-specific antler
characteristics (other than the range of antler potential
that may be reached at each age class, and this percentage
can’t be accurately estimated by viewing the
antlers). Therefore, I suggest you don’t rely
solely on antler size when aging bucks. Large antlers
on a younger deer and small antlers on an older deer can
negatively influence your estimated age. I prefer to
estimate age based solely on body characteristics with
respect to location and time of year and then use antler
size to “check” my estimate or to break a tie
if I can’t decide between two ages.
For more assistance, I recommend the book “Observing
and Evaluating Whitetails” by Dave Richards and Al
Brothers, as well as the pocket field guide to aging bucks
produced as a companion to this book. Also, QDMA has
produced an educational poster, “Estimating Buck
Age,” that uses photos of live bucks of known ages to
illustrate variations in body characteristics by age class.
Again, this makes a great visual aid for educating hunters.
All of these items are available at www.QDMA.com.
Aging bucks on the hoof is a lot of fun so whether you hunt
them with a bow, sporting arm or camera, this information
can make you a more knowledgeable whitetail enthusiast.
Kip’s Korner is written
by Kip Adams, a Certified Wildlife Biologist and Northern
Director of Education and Outreach for the Quality Deer
Management Association (QDMA). The QDMA is an
international nonprofit wildlife conservation organization
dedicated to ethical hunting, sound deer management and
preservation of the deer-hunting heritage. The QDMA
can be reached at 1-800-209-DEER or www.QDMA.com.