Someone ask for a ligitmate report documenting the long term effect using APR to manage a deer herd. Here in one from Pennsylvania. They started APR in 2002.
Antlers! Nothing captures the attention of a deer hunter more. Antlered bucks star in the dreams of many a hunter on the night before deer season. However, for years, most Pennsylvania deer hunters could only dream of harvesting a large antlered buck. Typically, bucks taken by hunters only had a chance to grow one set of antlers. Few had the larger antlers of an adult buck. One way to change this situation was implementation of antler restrictions. In 2002, the Pennsylvania Game Commission changed the antler restriction to harvest an antlered deer. Prior to 2002, the antler restriction was 2 points to an antler or a spike at least 3 inches in length. From 2002 to 2010, the antler point
restrictions (APR) were 3 or 4 points-to-an-antler
depending on area of the state. Starting in 2011,
the 4-point area changed to 3 points to an antler,
not including the brow tine. The 3 points-to-an –
antler area did not change. Since APRs began a
swirling of myth and reality has followed. Here
are the facts about Pennsylvania’s antler point restrictions.
The primary goal of APRs was to increase the
number of adult bucks (2.5 years of age or older)
in the population. By doing so, benefits of a more natural breeding ecology, an older buck age structure, and
greater hunter satisfaction might be realized. To achieve this goal, APRs needed to protect most yearling bucks
(1.5 years of age) from harvest. This required two different APRs: a 4-points-to-an-antler restriction in western
Pennsylvania and a 3-points-to-an-antler over the rest of the state (excluding junior hunters).
To assess biological and social aspects of APRs, the Game Commission initiated a multi-year study with the
U.S. Geological Survey’s Pennsylvania Cooperative Fish and Wildlife Research Unit at Penn State. This study
included the capture of more than 2,000 white-tailed deer and the surveying of more than 8,000 hunters. Additional information came from the Game Commission’s annual collection of deer harvest data.
BIOLOGY: Why Antler Points?
When defining antler restrictions, antler points and spread can be used.
Although hunters can judge both criteria in the field, we chose antler points.
APRs can be defined by any number of points; however, spread restrictions
are usually judged on the distance between ear tips. In many areas of
Pennsylvania, a spread restriction of 15” (a common ear tip width estimate)
would have protected nearly all yearling bucks as well as most adult bucks.
Although this level of protection would attain our goal, it would also make
many adult bucks ineligible for harvest. Antler points were chosen to protect
most yearling bucks and allow most adult bucks to be harvested.
Antler Restrictions in Pennsylvania Are they working?
BIOLOGY: Buck Survival
Prior to APRs about 80 percent of bucks (a majority of
which were yearlings) were harvested by hunters each
year. This led to buck survival rates of less than 20
percent. Protecting most yearling bucks would increase
buck survival thereby increasing adult bucks in the
population, the goal of APRs.
Based on survival rates of hundreds of radio-collared
bucks, yearling buck survival increased from less than
20 percent to 64 percent after APRs. Adult buck
survival increased as well to 36 percent.
BIOLOGY: Breeding Changes
With 80 percent of bucks being harvested each year prior to APRs, most bucks survived through only one
breeding season. Few older bucks were present in the population. Could APRs change the breeding ecology in
Pennsylvania’s deer herd?
Although yearling bucks are capable breeders, the dominance-based breeding hierarchy to which white-tailed
deer were thought to conform was absent in Pennsylvania due to the high buck harvest rate. This low number
of older bucks and “unstructured” breeding could have extended the breeding season. Would APRs and more
adult bucks lead to changes in breeding behavior, in particular conception dates?
From 2000 to 2007, data on breeding dates
from more than 2,500 females were
collected. Average date of conception prior
to APRs was November 17. Following
APRs, average date of conception was November 16.
In Pennsylvania, most adult does are bred in
mid-November and sexually mature female
fawns tend to peak about two weeks later.
Other aspects of breeding ecology, such as
pregnancy rates and embryo counts, have
also remained at stable and healthy levels.
Based on these data, it does not appear APRs significantly changed timing of breeding in Pennsylvania
BIOLOGY: Genetic Impacts
Concerns over genetic impacts of selective harvest are common. Would selecting bucks based on the number of
antler points they carried be enough to alter future antler development? Current research is clearly mounting
evidence to the contrary.
About 1 in 4 litters will have fawns with different fathers.
Research has shown yearling antler points are poor
predictors of future antler points and size.
Percent of hunters harvesting a buck is similar to previous decades.
First, yearling antler points are poor predictors of future antler
development. Research indicates little relationship between a buck’s
first set of antlers and those he carries at 4.5 years of age and older.
So, using yearling antler points as a harvest criterion should not
influence future antler development in the population as a yearling
spike buck and a yearling 6-point can have similar sized antlers by
age 4.5 years. Second, most of Pennsylvania’s antlered males are harvested after the breeding season. About 75 percent of Pennsylvania’s antlered deer
harvest occurs during the firearms season in late November and early
December. The peak of breeding is mid-November. As a result, most
antlered males harvested in Pennsylvania have already passed their
genes onto future generations. Third, a few mature males are not dominating breeding. In two different studies, yearling males successfully
sired fawns in populations with high percentages of older males. In fact, most males, regardless of age, only sired one litter.
Fourth, does are regularly being bred by multiple bucks.
Initially studied in captive deer, multiple paternity has
been documented in every free-ranging white-tailed deer
study in which researchers have looked. Populations
with different male age structures in different states have
seen litters with two or more offspring having different
fathers at rates of 20-24 percent.
Finally, a buck’s mother contributes half of his genetic
characteristics, but nobody can tell what a doe’s
contribution to her son’s antlers will be. There is no way
to visually evaluate the genetic antler potential of a doe.
As a result, 50 percent of the genetic contribution to
future antler development is randomly selected in Pennsylvania.
Given the complexity of the white-tailed deer’s breeding
ecology and high genetic variation, large-scale
alteration to Pennsylvania’s deer herd genetics is unlikely.
HUNTING: Hunter Success Rates
Increasing the standard for the harvest of a legal
buck with APRs could have reduced the number
of hunters that were successful. Tracking hunter
success rates over the last 3 decades has shown
little change in the percentage of successful
hunters. Today, licensed Pennsylvania hunters
are as successful harvesting a buck under APRs
as their predecessors were 20 years ago under
the old antler restriction.
HUNTING: Age Structure of Antlered Harvest
Age structure of the antlered harvest before APRs was about 80 percent yearling bucks and 20 percent adult
bucks. With the increase in survival of yearling bucks under APRs, the age structure of the antlered harvest
changed to about 55 percent yearling bucks and 45 percent adult bucks. This increase in adult buck harvest has
occurred during a time when overall deer populations have declined.
The increased harvest of adult bucks does not necessarily mean more “record book” bucks. Although age structure and number of adult bucks in the harvest has increased, about 75 percent of them are only 2.5 yearsof-
age. In other words, most of Pennsylvania’s bucks are still being harvested prior to growing their largest antlers.
HUNTING: Hunter Support
Prior to changing to APRs, surveys showed a
majority of hunters favored them. Many hunter
surveys have been conducted since APRs
started in 2002. Would hunter support wane
after APRs became reality? Not hardly! In
fact, hunter support of APRs has remained
steady since their implementation
CONCLUSION
After 6 years, APRs are a success. They have increased buck survival and the buck age structure. They have maintained strong support from hunters. And Pennsylvania hunters are experiencing the same levels of success
to which they are accustomed.
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