Since the mid 1950s DNR has collected data from hunter harvested
deer. When you take your deer to a meat processor, you may have seen staff
members from DNR's Wildlife and Heritage Service measuring antlers and examining
their teeth. Here is some information that will help you understand what the
wildlife biologists are doing and why.
Information gathered from a sample of muzzleloader and firearms killed deer
across the state provides a picture about the status of the deer herd in each
county. This information is important in assisting in the establishment of
seasons and bag limits. The information is equally valuable in evaluating any
changes made to Maryland's deer seasons. For example, the number of 17-month and
18-month yearling bucks in the annual harvest is monitored specifically to
ensure that too many bucks are not being harvested during the early muzzleloader
and bow seasons prior to the rut in early November. A rise in the number of 17
month or younger yearling bucks in the harvest would suggest that does were
being bred later in the season - possibly as a result of excessive buck harvest
in September and October that left too few bucks available for breeding in
All deer are sexed, aged and examined for any evidence of a deer disease
called hemorrhagic disease (HD). Bucks have the number of points counted.
Yearling (1 1/2 year old) bucks have the circumference of the base of each
antler measured. A basic guide to aging deer jawbones can be found here.
Young deer from 6 months old (button buck) to yearlings (1 1/2 years old) are
aged primarily by the replacement of milk teeth. Milk teeth correspond to human
"baby teeth". By age of 19 months all permanent teeth are in and the wear on the
lower jaw teeth are utilized. Dark bands (dentine) on the upper surface of the
teeth broaden in comparison to the light bands (enamel) as the deer ages.
Hooves are examined for evidence of past HD infection. Flaking hoof tissue
or grooves on the hooves may indicate that the deer contracted the disease in
late summer or early fall and survived. These deer do not have HD and are safe
Yearling bucks are indicators of any recent changes in the habitat or deer
herd. The size of the antler base informs wildlife managers about herd health
and potential reproduction. Any changes from the long term average would
indicate a change in deer habitat or herd health condition.
The sample age structure is entered into a model that estimates deer numbers and
for each year. These estimated deer population numbers indicate the changes in
statewide or regional deer populations in response to hunting seasons and bag
Brian Eyler, Deer Project Leader
Wildlife and Heritage Service
Maryland Department of Natural Resource
580 Taylor Ave, Annapolis MD 21401