Urban Deer Management: Characteristics, Options, and Studies
Presentation by Chad Stewart, MDNR Deer Management Specialist
Indiana’s liberal deer hunting seasons and bag limits are designed to maximize hunter opportunity and to provide land managers (landowners) a wider variety of options for managing hunting opportunities and hunting efforts to manipulate deer densities on their property.
Moreover, the IDNR has worked to alleviate conflicts with deer in urban areas through the creation of urban deer zones (UDZ). These UDZ are designed to target deer reduction efforts in portions of the state that experience increased deer conflicts and are densely populated.
White-tailed deer populations should be managed to 1) maintain a sustainable deer population, 2) retain the number of deer that a landscape can support while still remaining healthy over the long-term (ecological carrying capacity), and 3) minimize negative deer–human interactions (social carrying capacity)
For some people, knowing that wildlife exists in the natural environment provides a positive benefit to many people. However, activities associated with wildlife may result in economic losses to agricultural resources, natural resources, property, and threaten human safety. Therefore, an awareness of the varying perspectives and values are required to balance the needs of people and the needs of wildlife. When addressing damage or threats of damage caused by wildlife, wildlife damage management professional must consider not only the needs of those directly affected by wildlife damage but a range of environmental, sociocultural, and economic considerations as well.
Establishing practical expectations requires considering the biological complexities of deer management regarding the potential of 1) density-dependent reproductive responses, 2) time lags between population response to management and changes in condition indices and vegetation response, and 3) nonlinear relationships between deer densities and several key fundamental objectives.
“This year, 2010, was the first time since 1993 that (Trout Lily and) Michigan Lily were observed in blossom. Deer seem to have a special affinity for members of the lily family, and this plant is no exception. We have been anticipating the return of this species ever since the deer culls began in 1999.”
Many cities, counties, states and conservation organizations have produced Position Statements prior to having a full management plan. Here are a few:
In any given year, a harsh winter and other environmental conditions can cause a reduction in the deer population, although Dr. Underwood notes that the urban deer he has studied have about a 90 percent survival rate each year. According to Dr. Curtis, in order to keep the population stable (i.e., maintain zero growth), about half of the deer need to die every year.
The members of the Task Force believe that humane, non-lethal deer management methods– such as surgical sterilization– should be utilized whenever
possible, although most agree that lethal means may need to be considered in the short term.
The public is invited to provide input on the proposed expansion of the M-NCPPC Montgomery Park’s Dear Management Program for these parks in order to address damage caused by an increasing population of deer, including deer-related automobile accidents, damage to natural resources, and increased potential of communicable diseases such as Lyme disease. The decision to add this park to the deer management operations will be made after review of citizen complaints and input, and with strong support from the community.
Our research thus far includes literature review, three years of spotlight surveys, a herd health assessment, and preliminary findings from the first year of a long-term vegetation-monitoring effort. This research and informal consultation with wildlife biologists from a variety of agencies and backgrounds leads us to conclude that ecological benefits may be realized if a white-tailed deer population control program were to be instituted on Jekyll Island. These benefits could include:
- Increased regeneration of heavily browsed plant species including native hardwood trees
- Increased understory cover to improve habitat and forage for birds and small mammals.
White-tailed Deer Management in Northwest Austin: People and Wildlife in a Suburban Landscape, Kristina Schenck, St. Edward’s University
The question of managing and protecting nature for the benefit of both people and the natural world is one that does not have a comprehensive or immediate answer, and perhaps never will. Rather, a whole host of other questions arise when considering the choices we can make to address the issue of white-tailed deer overpopulation in urban areas. For one, how do we pay for expensive management practices? Furthermore, who pays? Even if we can’t completely solve the problem, is it worth it to buy time for future generations of people, whitetails and other flora and fauna? If we don’t pay now, what price will we pay later? If we choose to manage nature are we moving farther away from it? If we do nothing, are we ignoring the glaring signs?
White-tailed Deer have the ability to change the structure and composition of forests throughout their range. This coupled with their proliferation have led some to term the whitetail an ecological keystone species. However, they are a keystone species in many other ways, including economics, social values and traditions, aesthetics, disease, and more.
Cornell Cooperative Extension, the Wildlife Society– Wildlife Damage Management Working Group, and the Northeast Wildlife Damage Research and Outreach Cooperative
This booklet provides an overview of these complex issues and discusses the usefulness of various management options for resolving localized deer-human conflicts. The manual is intended for professional biologists and managers, community leaders, and others involved or concerned with suburban deer management.
Many factors associated with this species—such as the high reproductive output of white-tailed deer and the limited and varying abilities of natural limiting factors such as predators, disease, food, and cover to suppress deer population growth—can lead to problems, including the potential for an overabundance of deer to damage ecosystem health and negatively impact human safety. Conversely, in are as of the Chicago Wilderness region where active, sustained deer management occurs, native vegetation flourishes, habitat quality is high, and conflicts between deer and human populations have been reduced (e.g., some forest preserves and at Fermilab).
In East Hampton, the uncontrolled explosion in the deer population has reached an emergency level according to the Deer Management Working Group (DMWG). The DMWG proposes to address this emergency with a management plan that is comprehensive in its scope of solutions considered, effective in both short term results and long term sustainability and compassionate to all species, including people. The goal of this management plan is to restore balance and sustainability to the town’s natural environment.
- Deer whistles on vehicles do not work and provide a false sense of security.
- Need to harvest 40-50% of does to maintain population till next year
- The most economical and practical method of deer population regulation is…
Present densities of deer are often 30 – 50/km2 in large forests and 70 – 100/km2 in small forest blocks. However, ecological studies indicate that the maximal or threshold densities above which some ecological processes cease to function are varied and sometimes very low: 15 deer/km2 for migratory bird survival; 10deer/km2 for oak seedling recruitment; 8deer/km2 for forest shrub/vine regeneration; and 3 deer/km2 for white cedar regeneration.
Market Driven Suburban Deer Management: A New Model, Adam K. Downing, Extension Agent – Forestry & Natural Resources, Northern District, Virginia Cooperative Extension, 2010
His approach started with a two page survey he mailed to the 78 property owners in an area of approximately half a square mile surrounding his own residence/property. The written survey followed by personal visits resulted in 51 of the 62 responding owners (82%) supporting deer harvests. With this information in hand, Jerry had the framework needed to implement a trial program.
A study in Pennsylvania found that when deer density exceeded 20 deer per mile2, the number of plant and animal species present declined. The loss of low growing vegetation also reduces food supplies for deer. In overbrowsed areas, the condition of deer declines, and deer then become more susceptible to diseases, predation and winter losses due to malnutrition.
Quality Whitetails, Dec 2007How can you tell if deer exceed the carrying capacity of your habitat? With a browse impact survey. Read the article for specifics
Residents were surveyed to discover how they felt about the city’s urban deer population. Residents had mixed opinions about the sight of deer in their yards; however, most residents (73%) were concerned about getting into a deer-vehicle accident. Sixty-five percent of residents agreed with the use of urban bow hunting by recreational hunters in Stevens Point, significantly more than other culling techniques.
It is important for communities to develop measurable long-term goals and objectives as part of a comprehensive deer management plan before implementing deer control measures. Objectives based on deer abundance could be evaluated with standard deer survey techniques such as survey transects or time/area counts. Indicators such as frequency of deer/vehicle collisions, number of reported deer complaints, or predetermined reductions in landscape damage, could be used to measure cultural objectives.
The potential for deer populations to exceed carrying capacity, to impinge on the well-being of other plant and animal species, and to conflict with land-use practices as well as human safety and health necessitates efficient and effective herd management. In the absence of active management, deer herds grow until they reach the upper limit at which they can be sustained by local habitat. Herds at the “upper density limit” consist of deer in relatively poor health. These high-density herds are prone to cyclic population fluctuations and catastrophic losses. Such herds would be incompatible with local human interests and landuse practices…
In the absence of predation or hunting, this kind of reproduction can result in a deer herd doubling its size in one year. This fact was illustrated on the 1,146 acre George Reserve in southern Michigan where biologists at the University of Michigan have been studying the deer population since 1928. The deer herd grew from six deer in 1928 to 162 deer by 1933. More recently, the George Reserve herd grew from 10 deer in 1975 to 212 deer in 1980.
Lessons Learned: All communities concluded that lethal methods were necessary for reducing deer-related problems. Many communities also concluded that, because of access problems, hunting alone would not be sufficient to manage the deer herd. Consequently, hunting was often used in combination with some other type of lethal control measure. Technical learning took place through two primary mechanisms – gathering and interpreting information before management actions were chosen and learning through experience with managementactions that were implemented.
Having knowledge of deer biology, deer impacts, and the local landscape enabled the interagency partnership to make management recommendations that focused on reducing deer impacts, not on reducing deer numbers per se.
Deer Irruptions, Wisconsin Academy of Arts, Letters and Sciences, 1943
This is an old one, but lots of interesting info.
In 20 years, PA went from almost extinct to overrun with 1,000,000 deer.
The George Preserve is discussed.
The AZ example is complete with the collapse of the population.
The New Jersey State Legislature has reduced the safety zone for bow hunting from 450 feet to 150 feet from a building. With written permission in possession, Bowhunters may hunt within the 150-foot safety zone if they hunt from an elevated position.
The aim of this guide is to illustrate how deer population numbers and structure can vary over time. This guide is linked to the Management Plans, Cull Planning and Population Modelling guides which should be considered essential companion reading.