Management implications of an overpopulated white-tailed deer herd (Odocoileus virginianus)
and the effects of the recently suspended Earn-a-Buck program in Wisconsin.
By
Daniel J. Murray
An Undergraduate Thesis
Submitted in Partial Fulfillment for the Requirements of
Bachelor of Arts
in
Geography and Earth Science
Research Mentor: Dr. Kurt Piepenburg
Carthage College
Kenosha, WI
December, 2010
Management implications of an overpopulated white-tailed deer herd (Odocoileus
virginianus) and the effects of the recently suspended Earn-a-Buck program in Wisconsin.
Daniel J. Murray
Abstract
Overpopulated deer herds can have serious implications on both the human and natural
landscape. Among other things, uncontrolled deer numbers can increase the amount of deerrelated accidents and increase the spread of various diseases. Wildlife officials aim to set deer
population goals that will produce a healthy herd, a healthy ecosystem, and minimal damage
complaints, while still providing good hunting opportunities. In order to help meet these goals,
the Wisconsin Department of Natural Resources implemented their Earn-a-Buck program to
increase the pressure to hunt antlerless deer and decrease the overall deer population to levels
that the land can better support. Due to unprecedented amounts of criticism from hunters and
legislators, the Wisconsin DNR was forced to suspend their program in 2009. Although hunters
insist that the deer population is too low, available data implies that the deer population is still
well over the desired population goals. Maps created using GIS and numerous regression tests
were used to quantify the effects that the Earn-a-Buck program has had on the Wisconsin
landscape during the course of its existence. Over 75% of the deer management units in
Wisconsin are still over the set population goal and the statewide post-hunt population has not
been at or below goal since 1992. The total deer harvest has decreased by 47% from the year
2000 and it has helped lead to a decrease in the number of deer-related car accidents and injuries.
The total number of deer-related accidents decreased by 20.2% since 2000 and the number of
injuries resulting from this type of accident decreased by 41.2%. Although the total deer harvest
has decreased, the prevalence of Lyme and Chronic Wasting disease has increased during this
time frame. Some of this phenomenon could still be attributed to fact that some deer densities are
still well over the desired goals. Before its suspension, the Earn-a-Buck program had been
making significant progress toward lowering the deer population. Retracting the Earn-a-Buck
program now could eliminate all of the progress we have made towards reaching the desired
population goals and making Wisconsin a safer and more balanced environment. Most wildlife
experts in Wisconsin agree that, without continual intervention, Chronic Wasting disease will
spread further into state. While hunters may currently be complaining about the low numbers of
deer on the landscape, future hunts may be in even greater jeopardy as more and more deer
succumb to the disease. The best time to manage the disease is right now, while the numbers are
still relatively low and concentrated in one area.
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Table of Contents
Abstract……………………………………………………………………………….…….ii
List of Maps
Map A and B: Wisconsin Deer Management Units and Post-hunt
Population Goals (2009)…………………………………………………….20, 21
List of Graphs
Graph A: Deer Harvest and Licensed Hunters in Wisconsin……………………….22
Graph B: Total Deer Harvest and Deer-related Accidents………….……………...23
Graph C: Deer-related Accidents and Injuries in Wisconsin……………………….24
Graph D: Deer Harvest and Deer/Vehicle Crash Injuries in Wisconsin……………25
Graph E: CWD Prevalence in Wisconsin…………………………………………..27
Graph F: Deer Harvest and Lyme Disease Cases in Wisconsin…………………....28
List of Figures
Figure 1A: Total Deer Harvest and Deer-related Accidents
Regression Analysis……………………………………………………….23
Figure 2A: Deer-related Accidents and Injuries Regression Analysis
Figure 2B: Deer-related Accidents and Injuries Analysis of Variance……………24
Figure 3A: Total Deer Harvest and Deer-related Accident Injuries
Regression Analysis……………………………………………………….25
Figure 4A: Total Deer Harvest and CWD Proportion Positive (M)
Analysis of Variance
Figure 4B: Total Deer Harvest and CWD Proportion Positive (F)
Analysis of Variance……………………………………………………...26
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Figure 5A: Total Deer Harvest and Reported Lyme Disease Cases
Analysis of Variance……………………………………………………..27
Introduction…………………………………………………………………………………1
Methodology………………………………………………………………………………..15
Results………………………………………………………………………………………20
Discussion…………………………………………………………………………………..29
Management Implications…………………………………………………………..32
Future Research……………………………………………………………………..35
Acknowledgements………………………………………………………………………...37
Works Cited………………………………………………………………………………...38
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Introduction
The purpose of this research is to demonstrate how the Earn-a-Buck program has
effectively managed the deer herd in Wisconsin. I will argue that the program’s reinstatement is
necessary in order to even further lower the deer population and mitigate the negative effects that
deer overabundance can have on humans and the natural environment. The concept of attempting
to control the deer population in Wisconsin can be traced all the way back to the mid-19th
century and has continually been disputed by different groups and agencies. This deliberation,
now commonly known as “The Deer Wars,” has been argued tirelessly by those involved with
hunting, conservation, agriculture, and forest ecology all around the state. The relatively small
total deer harvests in recent years have further fueled this ongoing debate and hunter
dissatisfaction has even grown to require legislative proceedings. The approximate 330,000 total
registered deer harvest in 2009 is significantly lower than Wisconsin’s previous five-year annual
harvest average of 492,000 (Wisconsin Deer Harvest and License Sales 1966-03). Even more
notable, the Wisconsin DNR recorded a 47% decrease from the record-breaking 618,274
harvested deer in 2000. This decrease, largely in part to the Wisconsin Department of Natural
Resources’ attempts to control the deer population, has resulted in unprecedented amounts of
input and criticism from hunters around the state. Disgruntled hunters insist that the Earn-a-Buck
program has driven the deer population too low, but wildlife officials in the DNR believe that the
deer population is still well over the desired goal.
Wisconsin is recognized as one of the premier deer hunting destinations in the United
States and there is no denying the impact it has on the state’s economy and culture. The
Wisconsin Department of Natural Resources estimates that deer hunting generates more than $1
billion in total impact to the state’s economy every year and creates thousands of full and part
1
time jobs (Chronic Wasting Disease Background n.d.). It is also an important component of
Wisconsin’s recreational activities and tradition. Deer hunting contributes more than 7 million
days of recreation each year and the state continuously licenses over 600,000 hunters, one of the
highest amounts in the nation (Chronic Wasting Disease Background n.d.). Many businesses and
organizations benefit from good hunting years and rely heavily on the income generated from
high deer harvest numbers, including the DNR, whose license fees are a main source for agency
income. The National Survey of Fishing, Hunting, and Wildlife-Associated Recreation estimated
that each Wisconsin hunter spends about $1,500 on deer hunting (Wisconsin’s Deer
Management Program: The Issues Involved in Decision-Making 1998).
Besides hunters, who mostly argue for higher deer populations to simply improve their
hunt, most groups that demand higher deer levels are interested in monetary gain and the
financial implications that hunting has on the area. Many people fail to see the dangers that
overpopulated deer herds can cause and the negative affects they can impose on the landscape,
however. Although most hunters, and those who benefit from the revenue generated by the sport,
would like to see as many deer as possible, it is necessary for wildlife agencies to try and
mitigate the negative effects that deer can impose on humans and the environment. Sharon Levy
stated that uncontrolled deer numbers could increase deer-related accidents, increase the
incidence of tick-borne infections such as Lyme disease, and destroy forest diversity (Levy
2006). Ideally, wildlife managers aim to set population goals that will produce a healthy herd, a
healthy ecosystem, and few damage complaints, while still providing good hunting opportunities.
Wisconsin’s deer population is managed in smaller landscape segments called deer
management units (DMU). Wisconsin has over 130 of these deer management units and they are
used by the DNR to help monitor and control the deer activity throughout Wisconsin. Each unit
2
is required by administrative code to have its own deer population goal, which reflects habitat
conditions, winter severity, hunter demand, and impacts of deer on forestry, agriculture, and
deer/vehicle collision rates (Deer Management For 2000 and Beyond: Final Report 2000). The
DNR uses various data sources involving ecological carrying capacity, maximum sustainable
yield, and sociological carrying capacity to determine how many dear each management unit can
support and what the goal for each unit should be. According to DNR administrative code and
case stipulations on Chippewa treaty rights, the deer population goals must be reviewed every
three years (Deer Management For 2000 and Beyond: Final Report 2000).
After the latest review of the code, the new total goal for all of Wisconsin is now a posthunt population of 794,000 deer (Smith 2010). Researchers use an area’s deer range, only land
considered to be a suitable habitiat for deer, to determine the density of deer in a given location
and how many deer the land can support. The northern forest contains about 15,000 square miles
of deer range, the central forest contains about 2,300 square miles of deer range, and the
farmland regions of Wisconsin contain about 17,000 square miles of deer range
(Deer
Management For 2000 and Beyond: Final Report 2000). The current overwinter population goals
in the Northern Forest region are about 18 deer/mi2 of deer range. Goals in the Central Forest
range from 25-30 deer/mi2 and farmland units goals average 22 deer/mi2 (Deer Management For
2000 and Beyond: Final Report 2000). Since deer-vehicle accidents are a major concern in the
more urbanized counties, the population goals in the metro units are among the lowest in the
state (10 deer/mi2).
In order to help reach the desired population goals, the Wisconsin DNR implemented a
highly controversial Earn-a-Buck program. Earn-a-buck is an effective herd control measure that
3
requires hunters to tag an antlerless deer before being allowed to harvest a buck (a deer with at
least one antler 3” or longer in length). Hunters are only permitted to begin hunting for bucks
once they register their antlerless deer and are granted a Buck Authorization Sticker from the
deer registration station. The program was implemented in an attempt to reduce deer populations
that were well above the desired goals and alleviate the negative effect that deer overpopulation
was causing on the Wisconsin landscape.
The Earn-a-Buck program was so effective in reducing the total deer population because
it increased harvest pressure on antlerless deer. Other management methods like simply
increasing the amount of permits granted or lengthening the hunting season will not necessarily
reduce deer numbers to desired levels. In order to effectively manage deer populations, hunters
need to shoot more does and focus on subsistence hunting like those living on Indian
reservations in Wisconsin. Don Waller suggests that hunters need to “hunt more like wolves”
and shoot whatever deer they can, instead of focusing on impressive racks that will look good on
the wall (Levy 2006). Merritt Clifton supports this idea and claims that many current hunting
techniques are hardly a form of herd control at all. In areas where deer aren’t hunted, the buckto-doe ratio usually remains steady around 1:1, with each couple producing one or two fawns
every year (Deer Hunting Isn’t a Form of Herd Control. 2001). In areas where bucks are shot in
great numbers, the buck-to-doe ratio can raise to 1:7, and even as high as 1:30 in extreme
scenarios. Although the population decreases overall by the removal of large numbers of bucks,
the deer population continues to grow at the same rate because one buck could inseminate all 30
does, and produce as many as 60 offspring (Deer Hunting Isn’t a Form of Herd Control. 2001)
Deer management relies heavily on the shooting of does, but this idea clashes with many
of the traditions and hunting strategies used by today’s hunters. In the early 20 th century, deer in
4
Wisconsin were scarce and hunts were focused solely on bucks in order to improve the growth
rate and low population numbers. Many hunters carried on the tradition of only hunting bucks
and most of today’s “trophy hunters” search for only the biggest and most impressive racks. It is
rare to find many hunting groups that believe more deer, the better. Most hunters even pass on
smaller deer that come their way in hopes that bigger bucks will soon follow.
Three different concepts are considered when setting population goals: 1) the long-term
maximum number of deer the land can support, 2) the number of deer that produce the maximum
sustainable harvest, 3) the number of deer people are willing to tolerate (Deer Management For
2000 and Beyond: Final Report 2000). Although whitetail deer usually appear to be tame and
docile, overpopulated deer herds can be a legitimate nuisance to the people in the area and even
impose significant danger. According to the Insurance Institute for Highway Safety, over 1
million deer collided with cars in 2008 alone. These accidents resulted in the death of 150 people
and over $1.1 billion dollars in vehicle damage (Rooney 2003). In some counties in Wisconsin,
deer collisions account for up to 64% of all vehicle accidents (Deer Management For 2000 and
Beyond: Final Report 2000). As the population rises and the deer are forced to infringe upon
urban environments, they progressively become less and less frightened by human contact. These
areas become favorable homes to the deer, who are protected from hunters and have easy access
to gardens and ornamental shrubs for food. Many deer-related accidents now involve animals
that are no longer startled by traffic and do not attempt to avoid the vehicles until its too late
(Cillis 2008).
Deer that are accustomed to human presence also cause safety problems for airplanes at
airports and are now even spotted strolling down city streets and invading local businesses.
Several stories have been documented about businessmen who have found their places destroyed
5
by whitetail deer who have charged their reflection on the storefront windows. On May 2, 2010,
two bucks crashed through the Stout Ale House in Menomonee, Wisconsin. The deer crashed
violently through the front doors and sent pieces of glass flying in all directions. The total
damage caused by the deer totaled over $2,000 and a surveillance video shows a man who
narrowly escapes being hit by the animals (Horwath 2010)
The eating patterns of an uncontrolled deer population can also have a negative effect on
an area’s agriculture and economy. The United States is home to about 30 million deer, each one
eating nearly 500 kg of vegetation each year (Levy 2006). In farmland regions, biologists have
found negative impacts on plants and animals are most likely to occur when deer numbers
exceed 20-30 deer per square mile (Deer Management For 2000 and Beyond: Final Report
2000). In a study of 13 northeastern states, wildlife technicians discovered that deer caused about
$248 million worth of damage every year to the area’s agricultural crops, nurseries, and
landscaping (Drake 2005). In Wisconsin, high deer populations are responsible for 90% of the
wildlife crop damage (Wisconsin’s Deer Management Program: The Issues Involved in
Decision-Making 1998).
Deer damage to crops generally increases as deer populations grow above population
goals. Many farmers in Wisconsin have suffered serious losses where deer populations were
locally high and where high value crops were grown. Estimates based off the Wisconsin Damage
Abatement and Claims Service Program suggested that total crop damage in the state ranged
from $7 million to $28 million in 2000 (Deer Management For 2000 and Beyond: Final Report
2000). Many wild flowers, personal gardens, and parklands have been destroyed by deer, leading
to the disappearance of many plant species in the area and the refusal for many gardeners to
6
continue planting. Many Christmas tree farmers are forced to buy expensive electrical fencing to
protect their crops and landowners need to buy tree tubes to help seedlings survive.
Aside from being a nuisance to farmers and gardeners, the eating patterns of whitetail
deer can have serious implications on the forest ecology and entire ecosystem. Uncontrolled deer
population and overbrowsing has greatly reduced the plant diversity in the eastern United States
(Levy 2006). The Appalachian National Forest is now dominated by black-cherry trees and hayscented fern, simply because they can persist through the threat of high deer populations. The
high densities of these plants choke out most of their natural competitors and have spread across
the landscape. In Pennsylvania, hay-scented fern once covered less than 3% of the forest floor, a
number that has now increased to over 33% because deer feed so heavily on its competitors
(Levy 2006).
Don Waller of the University of Wisconsin-Madison insists that deer have dramatically
changed the plant communities in Wisconsin as well. He mentions that deer eliminate seedlings
of hemlock, cedar, and yellow birch and devour most understory plants. Because of
overbrowsing in Wisconsin, the forests in the area have recently become dominated by grasses,
sedges, and balsam fir (Levy 2006). Shannon Wiegmann, a botanist who conducted several
resurveys on plant communities in Northern Wisconsin Upland forests, reports that most plant
species spreading across the area can do so because of their ability to resist or tolerate deer
herbivory, while many decreasing species are sensitive to deer (Wiegmann 2006). Some
biologists have suggested deer population goals be set at 50% or less of carrying capacity to
reduce impacts on natural communities of plants and animals in forested landscapes (Deer
Management For 2000 and Beyond: Final Report 2000).
7
Deer also affect the growth and wellness of other animals in the area. On Anticosti
Island, deer that were introduced to the area years ago have now virtually destroyed a once
healthy black bear population by stripping away the gooseberries and currants (Cillis, 2008). In
Wisconsin, large numbers of deer can also diminish various plant species that other organisms
need to survive. The federally endangered Karner Blue Butterfly, for instance, depends on wild
lupine for its larval stage. Several other animals, such as the red-backed vole and the hooded
warbler, are negatively affected by overbrowsing and diminished forest floor vegetation as a
result of large deer herds (Wisconsin’s Deer Management Program: The Issues Involved in
Decision-Making 1998).
Overbrowsing can also have serious health repercussions on the deer themselves. As a
population approaches carrying capacity, food becomes limited. Overcrowding and food
shortages lead to unhealthy deer that suffer from the deficiency of many nutrients that they need
to survive. These malnourished deer are weak, underweight, and have small antlers. When a deer
reaches this unhealthy state they are also more likely to contract disease. Although a lot of
diseases that deer carry do not affect them, contact with an infected deer can cause sickness in
humans. These diseases, such as cryptosporidium and virulent E. coli, are usually passed from
deer to people through contact with deer fecal matter (Wisconsin’s Deer Management Program:
The Issues Involved in Decision-Making 1998). Because many areas are so overpopulated with
deer, the diseases are able to spread rapidly throughout the herd, similar to disease epidemics
spread by humans in crowded areas.
Deer also aid in the spread of Lyme disease to people because they often carry ticks that
harbor the Lyme disease-causing bacteria. Lyme disease was named after Lyme, Connecticut, an
8
area that became overrun with deer and was home to many of the first identified cases in 1975.
The disease is difficult to detect and difficult to treat in its advanced stages. If not treated early
by antibiotics, the subject may begin to experience severe neck stiffness, shooting pains, and
debilitating heart problems (Cillis, 2008). The ticks carrying the bacteria are usually only present
in places where there are large populations of deer and several areas have been calling for mass
culls because of the citizens’ fear of contracting the disease. It is widely acknowledged that
Lyme and all other deer-tick-borne diseases can be prevented by reducing the deer population
that the ticks depend on for reproductive success (Stafford 2004). It is suggested that by reducing
the deer population to levels of 8 to 10 per square mile the tick numbers can be brought down to
levels too low to spread Lyme and other tick-borne diseases (Stafford 2004).
Deer in Wisconsin are also becoming subject to the spread of Chronic Wasting disease
(CWD). Chronic Wasting disease was introduced into the state and was first detected in
Wisconsin on February 28, 2002 (Wisconsin’s Chronic Wasting Disease Response Plan: 20102025 2010). Chronic Wasting disease is a disorder similar to mad cow disease that is spreading
across North America by deer or elk, the disease’s only known natural hosts. Unlike
cryptosporidium and virulent E. coli, deer are indeed subject to affects of Chronic Wasting
Disease. Animals with Chronic Wasting Disease develop infectious protein particles (prions) in
the brain until most of the tissue develops sponge-like holes (Chronic Wasting Disease Harms
Deer and Elk. 2005). The clinical signs of the disease typically appear over 1.5 years after the
infection, as the prions accumulate and destroy the brain tissue. The affected animals exhibit
behavioral changes, progressive weight loss, lose coordination, and eventually die. There is
9
currently no available treatment or vaccination for the disease and all infections are believed to
be fatal.
The control of CWD in high density, free-ranging white-tailed deer populations has never
been attempted and there are no proven techniques to prevent its diffusion. Therefore, the
National CWD Management Plan can only recognize deer population reduction and the removal
of CWD-positive deer as the most likely to be effective for controlling Chronic Wasting disease
in the wild. Data from Colorado and Wyoming has demonstrated that Chronic Wasting disease
prevalence can reach high levels and become geographically widespread without control efforts.
Monitoring in these states also reveals that CWD can drastically reduce deer populations
(Wisconsin’s Chronic Wasting Disease Response Plan: 2010-2025 2010). Most wildlife experts
in Wisconsin agree that, without intervention, Chronic Wasting disease will spread further into
state. As the prevalence of the disease increases, many fear that the overall deer population will
decline and that the future my present limited opportunities to enjoy this Wisconsin resource.
The Wisconsin Department of Natural Resources Administrative Code NR 1.015(2)
states that: The primary goal of wildlife management is to provide healthy life systems necessary
to sustain Wisconsin’s wildlife populations for their biological, recreational, cultural and
economic values. Wildlife management is the application of knowledge in the protection,
enhancement and regulation of wildlife resources for their contribution toward maintaining the
integrity of the environment and for the human benefits they provide (Wisconsin’s Chronic
Wasting Disease Response Plan: 2010-2025 2010). In an attempt to fulfill their wildlife
management responsibilities, the Wisconsin Department of Natural Resources created a CWD
Management Plan with several objectives, including mapping the distribution of the disease,
investigating the possible origin of the disease in the state, minimizing the spread of the disease
10
to new areas, and completely eradicating the disease from the affected area (Wisconsin’s Chronic
Wasting Disease Response Plan: 2010-2025 2010). In order to meet these objectives, the
Wisconsin DNR has continually conducted great amounts of surveillance and testing for the
disease since 2002. Chronic Wasting disease has been found in 12 southern Wisconsin counties,
all of which are included in the current CWD Management Zone. The DNR has created this
Management Zone in an attempt to better monitor infected areas. Over the next 15 years, trends
in the population in this zone will be monitored by a combination of helicopter and fixed-wing
surveys and population modeling. This data will track CWD transmission and the effectiveness
of response efforts.
Since this disease is relatively new in Wisconsin and little has previously been done in an
attempt to control it, scientists have begun to conduct more research to find demographic
patterns involved with the epidemic in hopes to better understand how and why it spreads.
Research shows that the disease prevalence increases with age, simply indicating that risk of
infection increases with length of exposure (age) (Grear 2006). The study also found that males
are more subject to contracting the disease than females, largely in part to their social patterns.
Peak prevalence in three-year-old males (13%) was nearly twice that for females (7%) (Grear
2006). These numbers can largely be attributed to the relatively small home ranges that does
have (1.5-2.5 km²) in comparison to bucks (2-4 km²) (Grear 2006). Bucks move around more
throughout the year, meaning that they may become more exposed to the disease and they are
more vulnerable to coming in contact with other infected deer. Bucks are also at risk when
coming in contact with one another while competing for females and by visiting scent stations
(rubs and scrapes) used by infected bucks (Grear 2006). Data also suggests that there is a low
11
probability of does infecting their offspring early in life. The prevalence in fawns (0.5%) is low
compared to the prevalence in adult does (5.4%), signifying that mother-to-offspring
transmission is uncommon (Grear 2006). The Wisconsin DNR reports that only 23 out of more
than 15,000 fawns tested since 2002 have had the disease (Wisconsin’s Chronic Wasting Disease
Response Plan: 2010-2025 2010).
The recent spread of chronic wasting disease and research supporting its potential spread
to humans has also decreased the desire to hunt does. Although most organizations believe that
chronic wasting disease is not transmissible to humans, medical research suggests that it is
indeed possible to receive negative effects from eating infected venison. More laboratory studies
are needed to monitor the possibility of such transmissions, but initial research indicates that
humans may not necessarily be protected from animal prion diseases (Belay 2004). There has
been little to no evidence that humans can contract the disease, but many individuals dislike the
notion of eating any meat that could be considered infected. Many hunters take extreme
precautions when processing the meat and often times refuse to eat it at all, especially because
most signs of infection don’t show until over a year after the deer contracts the disease. There are
several guidelines for handling venison, including never touching or eating the eyes, brain, spinal
cord, spleen, tonsils, lymph nodes, or any part of a deer that appears sick. Hunters are also
encouraged to wear latex gloves and use a strong solution to clean everything that touched the
deer.
Deer management varies from area to area because each individual habitat can support
various amounts of deer. However, there are various universal criteria that wildlife agencies
12
follow to maintain healthy deer levels. A region can be considered overpopulated if the deer in
the area meet any of these conditions (Cromwell 1999):
1.) Deer negatively impact the vegetation and physical features of the environment.
2.) Deer populations exhibit a poor average body condition.
3.) Deer populations contain high disease prevalence.
4.) Deer are transmitting disease to humans and other species.
5.) High deer densities result in significant economic loss.
6.) High deer densities increase the risk of injury or death to humans.
The Department of Natural Resources felt that deer were overpopulated in Wisconsin and
that aggressive measures needed to be taken in order to reduce the number of deer to levels that
the land could better support. The Earn-a-Buck program was highly effective but hunters
despised it, insisting that they weren’t seeing any deer on the landscape and that they were
sometimes forced to pass up trophy bucks. The Natural Resources Board was even warned that if
they didn’t make a move, it was inevitable lawmakers would take over and do away with Earn-aBuck through legislation. The large amounts of pressure from hunters and legislators forced
Wisconsin wildlife officials to suspend the program in 2009 and look for other ways to control
the state’s deer population.
Being the most effective way to manage the spread of Chronic Wasting disease, the DNR
is allowed to continue its Earn-a-Buck program in the CWD Management Zone. Those hunting
in this zone must continue to shoot an antlerless deer before harvesting a buck, but during the
2010 deer season, no deer management units outside of the Chronic Wasting Disease
Management Zone will have Earn-a-Buck regulations. By removing the Earn-a-Buck program
from areas outside of the CWD Management Zone, the deer population in Wisconsin may return
13
to dangerously high levels and expunge the program’s efforts to mitigate the negative effects of
deer overabundance. To test whether the Earn-a-Buck program should be reinstated to even
further lower the deer population and mitigate the negative effects caused by overabundance, I
have generated the following hypotheses:
Null Hypothesis
The Earn-a-Buck program has had no effect in lowering deer-related accidents,
decreasing the prevalence of Lyme disease, and managing the spread of Chronic Wasting
Disease. The Earn-a-Buck program is no longer needed to lower the deer population in
Wisconsin.
Alternative Hypothesis
Through the course of its existence, the Earn-a-Buck program has effectively lowered the
deer population in Wisconsin and mitigated the negative effects of deer overabundance.
Hypothesis A: The Earn-a-Buck program has successfully reduced the total deer population in
Wisconsin, resulting in a decrease in the total number of deer-related vehicle accidents.
Hypothesis B: The Earn-a-Buck program has been an effective tool for managing Chronic
Wasting Disease by reducing overcrowding and successfully lowering the prevalence of infected
deer in Wisconsin.
Hypothesis C: The Earn-a-Buck program has influenced a decrease in the amount of reported
Lyme disease cases in Wisconsin by reducing the deer population that ticks depend on for
reproductive success.
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Methodology
This research on deer management covered the entire state of Wisconsin and various
geographical regions within it. Most of data acquired represents state-wide totals generated from
cumulative county and deer management unit figures. Some data was represented by individual
deer management units, or DMUs. The Wisconsin Department of Natural Resources has divided
the state into 133 of these deer management units and they are used regularly to help monitor and
control the deer activity throughout Wisconsin. Most of the available data on deer from the DNR
is classified into these units. Some data analysis also focused on the Chronic Wasting Disease
Management Zone, again, a predetermined study area created by the DNR in an attempt to better
monitor infected areas. Chronic Wasting disease has been found in 12 southern Wisconsin
counties, all of which are included in the current CWD Management Zone.
Most of the data involving the deer harvest in Wisconsin was acquired from the
Wisconsin Department of Natural Resources’ website. By law, hunters are required to register all
of their harvested deer. For decades, the DNR has diligently recorded these numbers and
compiled various data sets that portray deer harvest totals, along with what type of deer was shot
and how many licenses were granted. Total deer population estimates were also acquired from
the Wisconsin DNR. Estimating the deer population is a rather detailed and lengthy process.
Wildlife technicians in the DNR combine several variables and resources to compile a formula
that attempts to accurately predict the deer population. One of the most commonly used tools for
estimating the deer herd is the Sex-Age-Kill (SAK) calculation. There are several parts to the
SAK model: the buck harvest, the buck harvest rate, the age structure of bucks and does
harvested (the adult sex ratio), and the fall fawn-to-doe ratio. Most of the data that technicians
use in this model comes from the details collected from successful hunters when deer are
15
registered. They also combine data collected from ground tracking, aerial surveys, observation
surveys, and weather databases to improve their estimates. Aerial tracking occurs in the winter in
helicopters and fixed-wing airplanes when trees are leafless. Teams of two observers and a pilot
flying low and slow over farmland, wetlands and woods can get close enough to count deer on
the landscape and mark deer locations on aerial maps. Bucks are classified as deer with at least
one antler 3” in length or longer.
A map of the deer management units was created using geographical information systems
software called ArcMap. Data layers acquired from the Wisconsin DNR’s WebView program
were extracted as a shapefile and joined into ArcMap so Wisconsin’s deer management units
were available in the program. WebView is mapping tool provided by the DNR that allows users
to create custom maps and gain access to several databases. The program’s extract tool allows
users to clip out and download ESRI shapefiles for certain data layers and join them to different
GIS programs. Deer harvest data collected from the DNR website was properly entered into
Microsoft Excel and Microsoft Access so it could be readable and joined in the ArcMap
program. The deer management units’ FID codes were used so the acquired data could be
compatible in the shapefile and represented properly on the maps.
The maps depict all of Wisconsin’s Deer Management units and identify which units are
over the population goals. Different colors were used to identify what units are still above the
population goal and represent which areas are over by the highest percentages. Each unit is
required by administrative code to have its own deer population goal, which reflects habitat
conditions, winter severity, hunter demand, and impacts of deer on forestry, agriculture, and
deer/vehicle collision rates. The DNR uses various data sources involving ecological carrying
16
capacity, maximum sustainable yield, and sociological carrying capacity to determine how many
dear each management unit can support and what the goal for each unit should be. By using
mathematical functions, ArcMap was able to compare the relationship between the
predetermined goals and actual population. The map also portrays the percentage that each deer
management unit is over or under the goal.
A graph was used to represent the relationship between the total deer harvest in
Wisconsin in comparison to the number of licensed hunters over the last ten years. This graph
help depicts whether or not the total deer harvest has been affected by the amount of licensed
hunters. By using Microsoft Excel, a line graph was able to be generated that compared the two
data sets. The primary y-axis represented totals in the deer harvest and the secondary y-axis
contained figures representing the total number of licenses granted. The x-axis represented the
years of the data set (2000-2009). A trend line was added to the deer harvest data to represent the
general direction that the harvest numbers have been moving over the last ten years and if they
are increasing or decreasing overall. A trend line represents a trend, or the long-term movement
in time series data.
In order to compare the relationship between deer population and traffic accidents, data
was acquired from the Wisconsin Department of Transportation. This department classifies all
reported car accidents in the state and reports are offered in several levels of detail. These
statistics are based only on crashes reported to the Wisconsin Department of Transportation by
law enforcement officers and deer crashes self-reported by drivers are not included. The statistics
also do not include crashes caused by drivers avoiding deer. It is also important to note that a
reportable crash is defined as a crash resulting in injury or death of any person, any damage to
17
government-owned non-vehicle property to an apparent extent of $200 or more, or total damage
to property owned by any one person to an apparent extent of $1000 or more.
In order to quantify the effect that deer population has on the human environment,
various deer-related accident data sets were run through regression tests with the total deer
harvest data. This test finds an R value, which is a mathematical output that determines how
strong the relationship is between the dependent and independent variables. The data was
properly entered in the program SPSS, a computer program used for statistical analysis, and run
through the regression test. The program computes a table that, among other things, provides the
user with an r and p value. R values over .7 usually signify strong correlation, but that value is
considered to be even lower when studying human and animal behavior. The regression tests
were only statistically significant at p ≤ .05. Three different regression tests were run to examine
deer-related accidents, injuries, and the total deer harvest. The first test analyzed the relationship
between the deer harvest and deer-related accidents. Another test analyzed the relationship
between the deer harvest and the amount of injuries that have resulted from deer-related
accidents. The final test compared the relationship that exists between deer-related accidents and
the risk of injury.
Line graphs were also created using Microsoft Excel to visually compare the
aforementioned deer-related accident data and the total deer harvest. The total deer harvest data
was represented along the primary y-axis and the deer-related accident data was along the
secondary y-axis. By adding a secondary y-axis, the user is able to compare two different
variables over the same time period. Trend lines were added to both data sets to demonstrate the
overall long term movement of the data and compare how the data sets have been changing over
18
the years. A similar graph was made to compare the relationship between the deer harvest and
the amount of injuries that have resulted from deer-related accidents, as well the relationship
between deer/vehicle crashes and the risk of injury.
Regression tests were also used to examine the relationship between the total deer harvest
and the prevalence of chronic wasting disease. Many believe that deer overpopulation increases
disease prevalence and this test examines how the attempts to reduce the deer population have
affected CWD. The total deer harvest totals and Chronic Wasting Disease data will once again be
derived from Wisconsin DNR sources. The DNR has provided a data set that tracks CWD
prevalence since it was first detected in Wisconsin in 2002. Exact numbers of the total amount of
infected deer are near impossible to determine, therefore, the DNR uses a ratio to represent
disease prevalence that compares the amount of infected deer with the amount of deer they test.
A line graph was created using Microsoft Excel to visually portray the prevalence of CWD in
tested dear for both males and females since 2002.
Deer overpopulation has also been accused of increasing the spread of Lyme disease.
Data was collected from the Centers of Disease Control and Prevention (CDC) that confirms
reported Lyme disease cases by state. As with most other diseases, reporting requirements for
Lyme disease are determined by state laws or regulations. In most states, Lyme disease cases are
reported by licensed health care providers, diagnostic laboratories, or hospitals. States and the
District of Columbia share their data with CDC, which compiles and publishes the information
for the Nation. Similar to the deer-related accident analysis, the Lyme disease data was run
through regression tests in SPSS and graphed in order to find the correlation between the total
deer population and Lyme disease prevalence.
19
Results
A map was created in GIS using 2009 data that represents the total post-hunt deer
population in comparison to the deer population goal for each deer management unit in
Wisconsin. Overall, 90 deer management units were above the desired goal and 29 units were
below the goal (See: Wisconsin Deer Management Units and Post-hunt Population Goals
(2009)). 47 total units were over 50% higher than the desired goal, while two units were below
the population goal by more than 50%. 27 of these units recorded post-hunt populations that
were over 100% of the goal and two deer management units were above the goal by more than
500%. 19 units are not represented on the map because they are either registered as a non-quota
zone or they are independently managed.
Map: A
20
Map: B
The first chart was created to compare the relationship between the annual deer harvest
and the number of licensed hunters in Wisconsin from 2000-2009. As seen in graph A, the total
recorded harvest decreased from 618,274 deer in 2000 to 329,103 in 2009, a total decrease of
46.8%. The number of total licensed hunters remained relatively steady over the ten year span.
There were 952,714 licensed hunters in 2000 and 890,121 licensed hunters in 2009, a total
decrease of 6.6%. From 2000 to 20009 there was an average annual harvest of 470,807 deer and
903,078 licensed hunters, resulting in an average of .52 deer per license.
21
Graph: A
Deer Harvest and Licensed Hunters in Wisconsin
(2000-2009)
Total Deer Harvest
Licensed Hunters
y = -10907x + 530796
R² = 0.1676
Year
Wisconsin Dept. of Natual Resources
The harvest data was organized and run through regression analysis to compare the
relationship between the total deer harvest and the amount of deer-related traffic accidents in
Wisconsin from 2000 to 2009. The test generated an R value of .337 (Figure 1A). The total
number of deer-related accidents in Wisconsin decreased from 20,468 in 2000 to 16,338 in 2009,
a decrease of 20.2% (Graph: B). Regression tests were also ran to compare the relationship
between the frequency of deer/vehicle crashes and the resulting injuries. The test comparing
deer-related accidents and injuries resulting from deer-related accidents revealed an R value of
.905 and proved to be statistically significant at <.000 (Figure 2A and 2B). The total number of
injuries resulting from deer-related accidents decreased by 41.2% from 2000 to 2009 (Graph: C).
and had an R value of .483 when compared to the total deer harvest (Figure 3A/Graph: D).
22
Figure: 1A
Total Deer Harvest and Deer-related Accidents Regression Analysis
Model
dimen
1
R
R Square
.337a
Adjusted R Square
.114
Std. Error of the Estimate
.003
80561.516
sion0
a. Predictors: (Constant), Deer-Related Accidents
Graph: B
23
Figure: 2A
Deer-related Accidents and Injuries Regression Analysis
Model
d
R
R Square
.905a
1
Adjusted R Square
.819
Std. Error of the Estimate
.796
879.673
i
a. Predictors: (Constant), Injuries resulting from deer-related accidents
m
e
n
Figure: 2B
s
i
Deer-related Accidents and Injuries Analysis of Variance
o
n
Model
Sum of Squares
df
Mean Square
F
Sig.
0
1
Regression
Residual
Total
2.794E7
1
2.794E7
6190591.144
8
773823.893
3.413E7
9
36.110
.000a
*Deer-related Accidents and Injuries
Graph: C
24
Figure: 3A
Total Deer Harvest and Deer-related Accident Injuries Regression Analysis
Model
Std. Error of the
R
d
R Square
.483a
1
Adjusted R Square
.234
Estimate
.138
74913.211
i
a. Predictors: (Constant), Deer_Accident_injuries
m
e
Graph: D
n
s
i
o
Deer Harvest and Deer/Vehicle Crash Injuries in Wisconsin
(2000-2009)
n
0
y = -10907x + 530796
R² = 0.1676
Injuries
Total Deer Harvest
Total Deer Harvest
y = -36.448x + 868.67
R² = 0.9175
Year
WDNR/WDOT
Regression tests were also used to compare the total deer harvest to the percentage of
deer that tested positive to Chronic Wasting disease. The test used data starting in 2002, when
the disease was first detected in Wisconsin. The tests were verified as being statistically
insignificant for both males (.342) and females (.055) (Figure 4A and 4B). While the number of
harvested deer decreased by 11.5% from 2002 to 2009, the percentage of deer testing positive in
25
males increased by 14.3% from 10.5% in 2002 to 12% in 2009. The percentage of deer testing
positive in females increased as well, growing from 4.7% in 2002 to 6.4% in 2009, an overall
increase of 36.2% (Graph: E).
Figure: 4A
Total Deer Harvest and CWD Proportion Positive (M) Analysis of Variance
Model
1
Sum of Squares
Regression
df
Mean Square
5.160E9
1
5.160E9
Residual
2.914E10
6
4.857E9
Total
3.430E10
7
F
1.062
Sig.
.342a
a. Predictors: (Constant), CWD Proportion Positive (Males)
b. Dependent Variable: Total Deer Harvest
Figure: 4B
Total Deer Harvest and CWD Proportion Positive (F) Analysis of Variance
Model
1
Sum of Squares
df
Mean Square
Regression
1.668E10
1
1.668E10
Residual
1.762E10
6
2.936E9
Total
3.430E10
7
F
5.682
Sig.
.055a
a. Predictors: (Constant), CWD Proportion Positive (Female)
b. Dependent Variable: Total Deer Harvest
26
Graph: E
A final regression test was used to compare the relationship between the deer harvest
totals and the total number of reported Lyme disease cases in Wisconsin from 2000 to 20009.
Similar to the Chronic Wasting disease tests, the regression test proved to be statistically
insignificant at .248 (Figure 5A). While the total deer harvest decreased by 46.8% from the year
2000, the total number of Lyme disease cases increased by 209.4% (Graph: F).
Figure: 5A
Total Deer Harvest and Reported Lyme Disease Cases Analysis of Variance
Model
1
Sum of Squares
Regression
df
Mean Square
9.519E9
1
9.519E9
Residual
4.906E10
8
6.132E9
Total
5.858E10
9
F
1.552
Sig.
.248a
a. Predictors: (Constant), Reported Lyme Disease Cases
b. Dependent Variable: Total Deer Harvest
27
Graph: F
Deer Harvest and Lyme Disease Cases in Wisconsin
(2000-2009)
y = -10907x + 530796
R² = 0.1676
Lyme Disease Cases
Total Deer Harvest
Total Deer
Harvest
y = 147.12x + 429.47
R² = 0.8645
Year
CDC/WDNR
28
Discussion
Graph A was used to represent the relationship between the total deer harvest in
Wisconsin in comparison to the number of licensed hunters over the last ten years. Since 2000,
the total deer harvest decreased by 46.8%, but the total number of licensed hunters has remained
relatively steady and only decreased by 6.6%. This data suggests that the dramatic decrease in
the deer harvest cannot be attributed to the possible explanation that there are simply fewer
hunters every year. From 2000 to 2009, there was an average of .52 harvested deer per license.
This implies that the 62,593 fewer licenses in 2009 would only account for 32,548 of the
289,171 fewer deer from 2000, roughly 11%.
Because fewer licensed hunters only account for a small percentage of the decrease, it
can be established that other forces and variables have had a more significant impact on the total
deer harvest. The year 2000 was selected as the beginning time frame for this research because it
produced the highest total deer harvest by any state on record and it also marks the point that the
DNR decided to impose stricter Earn-a-Buck regulations. The graph visually portrays the effect
that the Earn-a-Buck program has had on the total deer harvest in Wisconsin since its initial
implementation. As seen on the graph, managing a species population does not produce a straight
decline, but it is rather a cyclical process that declines slowly over time, but increases and
decreases from year to year in response to post-hunt populations, winter severity, and breeding
cycles. Overall, the Earn-a-Buck program has helped lower the total deer harvest from 618,274
deer in 2000 to 329,103 in 2009.
29
Large amounts of pressure and criticism from hunters and legislators forced Wisconsin
wildlife officials to suspend the Earn-a-Buck program in 2009. Even though most hunters believe
that the Earn-a-Buck program had forced deer population levels to sink too low, the map created
using GIS represents how the majority of deer management units are actually still well over the
desired population goal. Over 75% of the deer management units included on this map are over
the set population goal and 23% of them contain deer populations than are more than doubled
what they should be. Overall, the total post-hunt population of 990,100 for Wisconsin was over
the desired goal of about 734,000 deer by 26%. In fact, the statewide post-hunt population has
not been at or below goal since 1992.
The top wildlife biologists in Wisconsin review these population goals every three years
and determine how many deer each management unit can support. The goals reflect each unit’s
ecological carrying capacity, maximum sustainable yield, and sociological carrying capacity.
Wildlife managers do not set their standards with solely the hunters’ best interests in mind, but
rather aim to set population goals that will produce a healthy herd, a healthy ecosystem, and
minimize the amount of deer-related damage. An overpopulated deer herd can have serious
implications on an area’s ecosystem, the spread of disease, and the safety of those who live there.
One of the largest concerns that humans have in regard to overpopulated deer herds is the
amount of deer-related traffic accidents and the resulting injuries. Wildlife technicians aim to
keep deer densities down, especially in metropolitan areas, in hopes to reduce the risk of
deer/vehicle crashes. The Earn-a-Buck program has reduced the total deer harvest significantly
since the year 2000 and it has resulted in a decrease of accidents as well. A regression test
comparing the two variables generated an R value of .337, which is a relatively strong value
30
when comparing human and animal activity. This signifies that there is a strong relationship
between the amount of deer on the landscape and the risk of getting into a deer-related accident.
The total number of deer-related accidents in Wisconsin decreased from 20,468 in 2000 to
16,338 in 2009, a decrease of 20.2%. The decrease in accidents has resulted in an obvious
decrease in injuries resulting from deer/vehicle crashes. The regression test comparing accidents
and injuries revealed an R value of .905, which is a significantly strong value and establishes the
idea that the Earn-a-Buck program has helped reduce the amount accidents on the streets and has
reduced the risk of injury for the people of Wisconsin. The total number of injuries resulting
from deer-related accidents decreased by 41.2% from 2000 to 2009.
The spread of chronic wasting disease is a growing problem in Wisconsin and the state
spends millions of dollars every year for research and disease management. It is widely
acknowledged that deer in overpopulated herds are at higher risk to contract disease because they
are in close proximity to other infected deer and there is a limited food supply. There are no
proven techniques to prevent the diffusion of Chronic Wasting disease, but deer population
reduction and the removal of CWD-positive deer are believed to be the best management
options. The original mission statement provided by the DNR enclosed an objective to reduce
and remove Chronic Wasting disease from affected areas in Wisconsin and wildlife technicians
hoped that the Earn-a-Buck program would help manage the disease and lower prevalence levels.
So far, there is no evidence that the management techniques have decreased the prevalence of
Chronic Wasting Disease. Regression tests comparing CWD prevalence and the deer harvest
totals were verified as being statistically insignificant for both males (.342) and females (.055).
While the number of harvested deer decreased by 11.5% from 2002 to 2009, the percentage of
deer testing positive in males increased by 14.3% from 10.5% in 2002 to 12% in 2009. The
31
percentage of deer testing positive in females increased as well, growing from 4.7% in 2002 to
6.4% in 2009, an overall increase of 36.2%.
The spread of Lyme disease in Wisconsin has also increased, despite the significant
decrease in the total deer harvest. The ticks carrying bacteria are usually only present in places
where there are large populations of deer. It is widely acknowledged that Lyme and all other
deer-tick-borne diseases can be prevented by reducing the deer population that the ticks depend
on for reproductive success. So far, there is no data that suggests that the decrease in the deer
population has resulted in decreasing Lyme disease prevalence. Similar to the Chronic Wasting
disease tests, the regression test proved to be statistically insignificant at .248 (Figure 5A). While
the total deer harvest decreased by 46.8% from the year 2000, the total number of Lyme disease
cases increased by 209.4%
Management Implications
Simply because the data does not suggest rapid change in the aforementioned disease
rates, it does not necessarily imply that the management techniques are not working and should
be discontinued. The Earn-a-Buck program is an effective management tool and the lower deer
population has already proven to positively affect the risk of deer-related accidents. The
prevalence of Chronic Wasting disease continues to increase, but deer population reduction is
currently the only viable large-scale management option and must be continued in order to
control the spread of the disease. Massive herd reduction is a plausible solution because it will
reduce the population density and therefore reduce the opportunities for transmission and
32
translocation. Although efforts have not decreased the prevalence of Chronic Wasting disease,
they may very well have at least slowed the rate at which it spreads.
Many people believe that the fight against Chronic Wasting Disease is a losing battle and
that the money spent for research could be used for better purposes. But data from Colorado and
Wyoming has demonstrated that Chronic Wasting disease prevalence can reach high levels and
become geographically widespread without control efforts. Monitoring in these states also
reveals that CWD can drastically reduce deer populations. Most wildlife experts in Wisconsin
agree that, without intervention, Chronic Wasting disease will spread further into state. As the
prevalence of the disease increases, many fear that the overall deer population will decline and
that the future my present limited opportunities to enjoy this Wisconsin resource. While hunters
may currently be complaining about the low numbers of deer on the landscape, future hunts may
be in even greater jeopardy as more and more deer succumb to the disease. The best time to
manage the disease is right now, while the numbers are still relatively low and concentrated in
one area. Without intervention, the disease could grow out of hand and create a problem that we
may never be able to recover from.
Although the number of Lyme cases continues to increase, the state of Wisconsin has
been taking the proper actions to reduce the prevalence of the disease. It is suggested that by
reducing the deer population to levels of 8 to 10 per square mile the tick numbers can be brought
down to levels too low to spread Lyme and other tick-borne diseases (Stafford 2004). There are
currently only three deer management units in Wisconsin that have a deer density less than 10
deer/mi². Although hunters think otherwise, the deer herd in Wisconsin is still overpopulated and
needs to be smaller in order to reduce the risk of tick-related diseases. The program has yet to
33
reduce all of the deer management unit densities to lower levels near the desired goal, but it has
been making significant progress. Retracting the Earn-a-Buck program now could eliminate all
of the progress we have made towards reaching the desired population goals and making
Wisconsin a safer and more balanced environment.
For several years, the DNR has demanded that each hunter tags an antlerless deer before
they can shoot a buck and it has proven to be an effective management program. The reduced
deer herd has resulted in an increased amount of disgruntled hunters who reportedly see less deer
on the landscape and often times are not allowed to shoot a buck because they have not
previously shot a doe. This deliberation, now commonly known as “The Deer Wars,” has been
argued tirelessly by those involved with hunting, conservation, agriculture, and forest ecology all
around the state. Those interested in transportation safety, controlling disease, and preserving
natural forests believe that the population numbers should be driven lower, while those who
support hunting and the money generated from it demand more deer. I believe that the Earn-aBuck program needs to be reinstated in order to continue to manage the growing amounts of
disease prevalence in the state and continue the positive results it has accomplished in reducing
deer-related traffic accidents.
I argue for full reinstatement of the program, but believe the Earn-a-Buck regulations
could at least be altered to meet the needs of both wildlife biologists and the thousands of deer
hunters that participate in Wisconsin’s hunting seasons every year. The Earn-a-Buck program
should remain in place for all deer management units in the Chronic Wasting Disease Zone and
at least be in effect for all deer management units that host a deer population more than 20% of
the desired goal. Although it would be at a slower rate, ideally the overall deer population would
34
continue to decline and the statewide deer population estimates would lower closer to the desired
goal. This program would create a better balance between hunters and wildlife officials. The deer
populations would continue to decrease overall, but there would still be plentiful hunting
opportunities and under populated units would be able to grow.
Future Research
There is a lot of opportunity for further research in this topic, especially after the
suspension of the Earn-a-Buck program and the data that will be available in the next few years.
Researchers will now be able to examine the Earn-a-Buck program more closely and evaluate the
effect that it had on the environment. New data in disease and deer-related accidents will confirm
whether or not the program had been working and if it is necessary to help solve the problems
that are often associated with deer overpopulation. A significant increase in deer-related
accidents and disease prevalence could signify that the Earn-a-Buck program had been fulfilling
its intended task. The data also needs to be continually monitored over the next few years to fully
understand the program’s effectiveness. 2009 marked the lowest deer harvest the state has
produced in years and residual effects may not be noticed for years to come.
More research could also be done to incorporate how the changing weather patterns
affect the total deer population. Severe winters in northern Wisconsin can eradicate up to 30% of
the deer herd. With continually changing global temperatures more deer may or may not survive
through the upcoming winters. Winter severity could play a large role in the deer population
management process and affect the need for mass culling.
35
This research project has only examined a few of the problems associated with deer
overpopulation. More research could be done to study the effects that deer have on several other
variables in Wisconsin like forest ecology and damaged farm products. These findings could
either support or refute the idea that the Earn-a-Buck program has been positively affecting the
physical and human landscape.
36
Acknowledgements
-
Special thanks to Dr. Kurt Piepenburg and Dr. Joy Nystrom Mast for continual
guidance, support, and encouragement throughout the research process.
-
Additional thanks to Jessica L. Rees, a Wisconsin DNR employee. Jessica’s patience
and assistance helped me acquire data sets needed to complete my thesis research.
37
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39