NE1005: Management of Wildlife Damage in Suburban and Rural Landscapes
(Multistate Research Project)
Status: Inactive/Terminating
NE1005: Management of Wildlife Damage in Suburban and Rural Landscapes
Duration: 10/01/2001 to 09/30/2006
Administrative Advisor(s):
NIFA Reps:
Non-Technical Summary
Statement of Issues and Justification
Wildlife species cause extensive damage to agricultural commodities, forest regeneration, and suburban landscapes in the Northeast (Conover 1997, NEWAA 1997). In Pennsylvania alone during 1994, farmers estimated that wildlife caused $74,042,000 in losses for 6 crops (Tzilowski et al. 1997). Deer, in particular, pose a problem within Pennsylvania's Allegheny hardwood forest, as the annual timber loss due to deer browsing is estimated at $367 million per year (Diefenbach et al. 1997). Deer also have a negative impact on landscape ornamentals in suburban settings, resulting in $6.5 to $9 million in losses in Westchester County, New York, alone (Connelly et al. 1987). Deer management concerns have caused social conflict in many Northeast communities (e.g., Princeton, NJ; Fox Chapel, PA, Cayuga Heights and Irondequoit, NY; Groton-Long Point, CT; etc.). Economic losses caused by deer exceed those for all other vertebrate pests (Wylwialowski and Beach 1991). In Pennsylvania, deer-vehicle accidents account for more than $130 million in insurance claims. In addition, it is estimated that more than 150,000 deer-vehicle collisions likely occur in New York and Pennsylvania annually, and traffic safety statistics indicate about 4% of these accidents result in human injury (Conover 1995). The Center for Disease Control has also indicated that half or more of the 16,000 new cases of Lyme disease diagnosed each year in humans occur in the Northeast where deer have been implicated as hosts for the ticks that carry the disease. Many stakeholder groups, including fruit, vegetable and ornamental growers, cooperative extension educators, state and federal wildlife agency staff (Packham and Connolly 1992, Bruggers et al. 1996), and community leaders have indicated that wildlife damage management is an important concern. New, multi-state approaches are needed to both reduce deer overabundance and mitigate damage in communities across the region.
Because deer concerns (Appendix D- vehicle accidents, plant damage, Lyme disease) are similar between several Northeast states, this proposal would pool State Agricultural Experiment Station (SAES) resources for high-priority wildlife damage research. The Northeast Association of Fish and Wildlife Agency Directors (NEAFWA) have recognized the advantages of regional coordination and have provided limited base funding to support a Northeast Wildlife Damage Research and Outreach Cooperative (the WDM Coop includes a consortium of 13 NE states; research priorities listed in Appendix D). If this proposal were funded, we would in essence create an informal partnership between NERA and NEAFWA and provide for agency-university coordination of wildlife damage research across the Northeast. This partnership would set a precedent that could serve as a model for other regions in the United States. Agricultural producers would experience increased profitability resulting from less wildlife damage. Suburban residents would experience fewer deer-car collisions and reduced damage to ornamental plantings. Hardwood forest regeneration would increase. Through enhanced outreach programs, landowners in the Northeast could experience a lower incidence of Lyme disease.
In addition to deer concerns, populations of non-migratory, giant Canada geese have increased dramatically in the Atlantic Flyway during the last 50 years and are causing economic impacts (Conover and Chasko 1985, Castelli and Sleggs 2000). Many stakeholders (e.g., park managers, golf course superintendents, grain farmers, etc.) currently view Canada geese as a pest species (Conover and Kania 1991, Gosser and Conover 1999). Among the problems resulting from increased goose numbers are grazing and trampling damage to grain and forage crops. Accumulations of goose droppings on lawns, parks, golf courses, and athletic fields create unsightly, messy, and foul-smelling experiences for people using those areas. Fecal contamination of water bodies and drinking water reservoirs causes eutrophication (Conover and Chasko 1985). Furthermore, there is increasing concern of possible disease transmission to people from contact with goose feces. Potential collisions between birds and aircraft, and associated loss of human life, is a real risk near many airports in the Northeast US. In the mid 1990s, as U.S. Air Force AWAC plane struck a Canada goose on take-off causing an engine fire which destroyed the aircraft and killed 24 crew members (York et al. 2000). An integrated bird control program was initiated at this airport to prevent future disasters.
Canada geese are migratory and the need for coordinated, region-wide research and management is obvious. Priorities for goose management and hunting seasons are set at the Atlantic Flyway level by the United States Fish and Wildlife Service (USFWS). Although the USFWS establishes a broad framework for goose management, it is not sufficient to address critical goose conflicts within and between Northeast states. Goose management issues are often perceived at the community level (e.g., damage to grain fields in a township, or fouling of beaches at a park), and the USFWS framework is not designed to address local issues. To effectively study and manage geese at the community level, SAES scientists will need to partner with state wildlife agency staff. Coordination of goose banding and control efforts will be required to evaluate the impacts of research projects and understand the population dynamics of geese as they move between states.
We propose to examine ways to more effectively manage goose reproduction and disperse geese causing conflicts. Any control program involving the handling of geese or eggs will require both state and federal permits, and goose banding/marking will need to be coordinated between states. Although research and dispersal of problem geese will occur at the community level, multi-state collaboration and monitoring will be needed to determine if geese hazed in one area simply move across state boundaries and cause conflicts in another location. There is increasing evidence that a large proportion (80-95%) of geese dispersed prior to egg hatching will molt-migrate into northern Canada and remain there throughout the summer months (Abraham et al. 1999). This could eliminate many suburban conflicts with geese at parks, golf courses, and athletic fields which peak during summer.
Research priorities for deer damage management in the Northeast include assessment of economic losses, development of methods for mitigating deer impacts and non-lethal management of herd growth (NEWAA 1997, Appendix D). For Canada geese, research priorities include improved methods for excluding geese from turf grass areas and crops, and development of socially-acceptable methods for controlling goose abundance. These topics will be the primary focus of the Multi-state Technical Committee during the initial 5 years of the project. However, it is clear that wildlife damage management needs exist for many other species in the Northeast (Appendix D), and these could provide the focus for future research and outreach.
We propose to standardize research methods for estimating deer abundance and assessing deer damage levels in states across the Northeast. These data are important for both documenting current impacts, and as a baseline for measuring change following future management actions. In addition, investigation of the social acceptability of various deer and goose management alternatives is important for determining the potential adoption of novel wildlife management approaches.
Note: Literature Cited is listed in Appendix C.
Related, Current and Previous Work
Many agency and university scientists have completed independent research projects to mitigate wildlife impacts (Appendix B), however there is little cooperation and coordination between states in the Northeast. Increased collaboration among key State Agricultural Experiment Station faculty and wildlife agency cooperators (state and federal) is needed to promote consistent, multi-state approaches for resolving wildlife conflicts. Scientists involved with this project have provided the core of wildlife damage management research and outreach in the Northeast during the past 10 years (Appendix A). A CRIS database search indicated only one Western Regional Project (WCC-95, Vertebrate Pests of Agriculture, Forestry, and Public Lands; Dallas Virchow, Chair, Univ. of Nebraska) related to wildlife damage management. This project has focused primarily on predator control for the livestock industry, and toxic baits for controlling rodents such as ground squirrels and pocket gophers. If approved, a multi-state State Technical Committee would provide a regional project similar to WCC-95 that focused on priority wildlife damage concerns in the Northeast (e.g., problems associated with overabundant deer, Canada geese, etc.).
The CRIS database search for wildlife damage-related research projects (n= 18, Appendix B) indicated there were 10 new or revised projects nationwide, and 8 previous studies that had been terminated. Most previous and current wildlife damage work is located in the Western and Southeastern Regions. Only 3 of the active wildlife damage projects are located in the Northeast (2 at Cornell University and 1 at the University of Maryland). There were no multi-state projects in the Northeast related to wildlife damage management on the CRIS database.
There are many wildlife-related problems where additional research would enhance crop production, human health and safety, and suburban landscape management. A list of high-priority research topics has already been developed and prioritized by the Northeast Wildlife Damage Management Research and Outreach Cooperative (Appendix D), and this list has significant overlap with a research needs assessment conducted by the USDA-National Wildlife Research Center in 1996.
The Northeastern states are uniquely positioned to conduct additional research on the integration of the biological and social dimensions of wildlife damage management issues. The Human Dimensions Research Unit at Cornell University conducted pioneering research on deer damage in agriculture and suburban landscapes in New York. However, most of those surveys are at least 15 years old. Growers are reporting increasing deer impacts to crops in NY, NJ, PA, VA, WV and other states. Within the last 5 years, independent deer damage surveys were completed in NJ (Drake 2001) and VA (J. Parkhurst, pers. commun.). A single survey with consistent design and implementation is needed to assess the Northeast regional impacts of deer in both suburban and agricultural landscapes. These baseline data will provide a benchmark for evaluating future impacts of wildlife management actions. Also, it is important to know the magnitude of wildlife damage for various crops so that research effort can be focused on those commodities with the greatest economic losses.
Wildlife damage is of increasing importance in both rural and suburban landscapes. Often population-level control is needed to reduce wildlife impacts to crops and ornamental plants, yet some stakeholder groups are opposed to lethal control of deer, geese, and other large vertebrates. Consequently, the social acceptability of various management alternatives must be clearly examined and integrated into approaches for managing wildlife impacts. Resources should be spent on effective management actions with the greatest potential public acceptance and likelihood of adoption. Improved and standardized damage assessment techniques are needed to clearly document the impacts of control alternatives and make between-state comparisons across the Northeast. It is important to document the conditions (e.g., scale, wildlife density, landscape features, etc.) under which new management techniques will or will not work.
Objectives
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Assess the impacts of deer damage on stakeholders and the social acceptability of wildlife management alternatives.
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Evaluate and improve techniques for estimating deer abundance and damage assessment under current and alternative management scenarios..
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Design and develop new techniques and test concepts to reduce suburban Canada goose impacts by lowering nest success and increasing dispersal during summer.
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Methods
Objective 1Assess the impacts of deer damage on stakeholders and the social acceptability of wildlife management alternatives.
A mail survey will be designed to assess three primary topics: (1) economic impact of deer conflicts (e.g. damage to landscaping, fruit trees, vegetable crops and forest regeneration, incidence of automobile accidents, extent of damage to automobiles), (2) perceived risks of encounters with deer (e.g., fear of hitting deer while driving, concerns related to Lyme disease), and (3) perceived costs and benefits of alternatives for deer damage management (e.g. social acceptability, Loker et al. 1999). Questions will include an assessment of of agency recommendations for dealing with wildlife conflicts and stakeholder satisfaction with available management options. Analysis of the survey data will further conceptual development of wildlife acceptance capacity (Decker and Purdy 1988) and risk perception (Stout et al. 1993) with particular application to white-tailed deer management. Loker et al. (1999) demonstrated that residents' concern about wildlife were elevated by increasingly severe problem experiences. Development of a questionnaire will be coordinated by the Multistate Technical Committee with participants from each collaborating state (CT, MD, NJ, NY, PA, VA, WV). Development and implementation of a multistate stakeholder survey will be coordinated such that results from participating states can be aggregated. Adequate samples of questionnaires for statistical analyses will be distributed in participating states to 3 key stakeholder groups: farm owners, residential property owners, and private forest landowners. A standard 4-wave mailing technique as recommended by Dillman (2000) will be used to maximize return rates. If return rates are less than 65% for any group, a telephone non-response survey would be completed to detect and adjust for any non-response biases. Study design, data entry, and preliminary analyses would be coordinated by the Cornell Human Dimensions Research Unit. Results will be compared for stakeholder groups and commodities both within and between states.
Objective 2
Evaluate and improve techniques for estimating deer abundance and damage assessment under current and alternative management scenarios.
1. Deer density assessment. We will identify a minimum of 6 communities (at least 2 each in 3 participating states) that are presently using one or more deer population estimation techniques (CT, MD, NJ, NY, VA, and/or WV). The costs, reliability, utility and other aspects of the estimator(s) will be assessed using a standard protocol. In a select number of communities, a range of different population estimators not presently being used, will be tested to determine their relative accuracy. For example, a community that has used infrared aerial imagery to assess deer abundance will be researched to test the accuracy of other techniques (e.g. spotlighting, infrared-triggered cameras, etc.) to compare accuracy, practicality, and cost. From the database that is developed, standards of reliability, cost-effectiveness, limitations, and other aspects of each estimator will be compared.
The majority of this research will occur over a period of two years, with direction and leads on suitable communities obtained from state wildlife extension specialists and state agency wildlife biologists. The combined efforts of the principal investigators from each state will be monitored by the Multistate Technical Committee. The committee will develop standard protocols and an experimental design that will be applied in each state. The actual number of communities where additional population estimation techniques will be implemented will depend on available resources. Selection preference will be given to communities where higher cost estimation techniques (i.e. infrared, helicopter) are either ongoing or have already been completed. The three deer population assessment techniques selected are likely to produce the most reliable estimates of abundance in suburban areas closed to hunting.
Spotlight Counts:
Spotlight counts of deer along roadsides have commonly been used to estimate deer abundance (Eberhardt 1968, Cypher 1991, Storm et al. 1992). The accuracy of the density estimate is proportional to the number of animals counted, thus it is important to obtain large sample sizes. This is especially relevant when trying to compare seasonal changes and changes in habitat use. One potential drawback is that deer could be attracted towards roads (or repelled away from roads) at certain times of the year, thus resulting in an over estimate (or underestimate) of population densities. Although most roads are not straight, they can still be used to sample deer as long as the curvature of the road does not allow the observer to count the same animal or herd of deer from another point on the road (Sukumar at al. 1991).
The study sites will be stratified into sampling units. Existing roads at the selected sites will be used as transects, and each road will be surveyed at night using a spotlight 3 times per month from late summer through winter. The effective strip width will be calculated along the roadsides so each count can be converted to a density estimate (Sage et al. 1983). Advanced statistical procedures for line-transect sampling will be used to analyze spotlight data (Buckland et al. 1993, Laake et al. 1998).
Infrared-triggered camera count:
The habitat stratification and sampling units used in the infrared-triggered camera method of estimating deer density (Jacobsen et al. 1997) will be similar to those used in the spotlight count. Infraredtriggered cameras will be set up at a density of 1/60 ha. Corn bait will be placed in front of each camera to lure deer to these locations. Cameras will be loaded with new film daily during each 6-day sampling period. Branch-antlered bucks can be identified using antler configuration, antler mass and other body traits. Females and young with distinguishing characteristics will also be identified. Using the branch-antlered bucks to identify individuals, the population size will be estimated by using the Lincoln-Petersen Index for mark-recapture data (Overton 1969, McCullough and Hirth 1988).
Aerial survey count:
An aerial survey will conducted at each site during the first winter of the study when suitable snow cover is available. The survey will use Forward Looking Infrared (FLIR) scanning technology (Koerth et al. 1997). The protocol involves an infrared imaging camera system mounted on a helicopter (Wiggers and Beckerman 1993). After the census area has been established, a flight grid will be set up and the helicopter will cover the grids at an altitude of approximately 500 feet (Beasom et al. 1981). All deer sighted will be classified by sex and age and group size.
2. Deer Impact Indicators. - Communities selected for this research will be a subset of the group considered for deer density assessment. Special consideration will be given to those communities in participating states (CT, MD, NJ, NY, VA, and/or WV) that already have well-developed mechanisms for documenting damage impact data, as well as the desired data on measuring deer abundance.
A deer impact index that relates damage intensity to deer population levels has been developed with the recognition that the amount of forage produced on the landscape will affect deer impacts at a given density. Concepts such as Relative Deer Density (deCalesta and Stout 1997) have been applied to rural woodlands and may be a useful tool for describing the interactions between deer and their ecosystems in the community environment. Much of the above work focuses on rural lands and there is a need to apply and develop similar models for suburban communities. It is necessary to look at some "common currency" that can describe deer abundance given a certain level of forage or landscape area, which can then be predicted from damage impact indicators. These indices must be easy to use and measure, with known costs and reliability of estimates.
A major consideration is the determination at which scale a community wishes to relate abundance, damage indicators and effects of management options. McNulty et al. (1997) found that localized deer removal in parks and suburban areas did not result in rapid invasion by other deer. Therefore, data on deer abundance, damage indicators, and management effects must be considered in light of past practices, as well as the scale of the area. Landscape considerations and herd characteristics must be considered when choosing how to divide up areas into meaningful management units. While some damage impact estimators will be available, others will not in all communities studied.
Deer impact indicators will be context specific for different communities dealing with wildlife conflicts. Part of the proposed research is to develop ways to assess and make predictions about the relative weights of various impacts. This will be accomplished first through qualitative methods (e.g., focus groups), and then more broadly via quantitative analyses (e.g., mail surveys). A classification of various impact indicators has already been developed (Decker et. al. in Review), and will be used as a guide.
The majority of this research will be conducted over a two-year period by state agency scientists and state wildlife extension agents. The principal investigators will work with the Multistate Technical Committee to coordinate the efforts of all those in involved. Work will be conducted in the selected communities to collect data on the desired damage impact indicators. This will require the development and application of standard protocols so that results between communities can be contrasted and compared. Appropriate data analysis techniques will be used to develop predictive relationships between deer abundance and damage indicators at the community level.
3. Deer Damage Case Studies. - Communities will be selected that are presently implementing different management programs (e.g. sharp-shooting, controlled hunting, immunocontraception) to manage deer populations. These will include communities that were involved with the research above, but will not be limited to those communities. Existing case studies of deer management programs in different suburban communities from different states across the Northeast will be compiled and analyzed. Available information on deer abundance and damage impact indicators will collected from these communities as well. Using the available data, the relationship between management programs, deer abundance, and damage will be developed.
This project will follow a logical sequence of relationships that are not commonly used by communities when dealing with deer management issues. First, assessment of deer population estimation technique(s) must be made for the specific situation based on available funds, amount of error, need for sex and age information, and practical and logistical concerns. Second, a predictive relationship between deer abundance and damage impact indicators should be developed at the community level. Measures of forage availability and landscape patterns will likely be key components to quantify. Such a relationship is not well understood and this study can provide guidelines how to cost-effectively collect deer impact information and what types of policies are needed to make it happen. Data could include the collection of information on deer-vehicle collisions, browsing on plants, and other indicators. Because collection of damage indicator information is in some cases less expensive, this can minimize the use of more expensive deer abundance techniques. This research can provide community leaders a toolbox of options.
Currently, many techniques are being utilized to manage deer (Curtis et al. 1994). Additional research must be conducted to evaluate the relative effectiveness of these methods, and then monitor deer abundance and impacts to determine which method or combination of techniques is most effective in a given community. The proven IPM context for evaluation and monitoring impacts will be employed. This research will help participating communities determine the percentage by which a deer population must be reduced to lower the number of deer-vehicle collisions, damage to landscape plants, etc. to a socially-acceptable level. It is essential that an accurate estimate of the threshold or tolerance for damage be measured through social analysis.
Finally, after a community has established methods to assess deer abundance, damage indicators, and the relationship between the two, the impact of different management options can be evaluated. In fact, depending on deer abundance at the community level, certain management options may not be feasible because they will fail to reach the desired impact reduction and/or be socially unacceptable. Communities throughout the Northeast face similar situations with deer and the duplicity of effort in collecting data and understanding impacts could be reduced by practical research that establishes the relationships between deer abundance, damage impact indicators, and management options.
Objective 3
Design and develop new techniques and test concepts to reduce suburban Canada goose impacts by lowering nest success and increasing dispersal during summer.
Although hunting can successfully reduce goose numbers in many rural areas (Conover and Chasko 1985, Heusmann 1999), it may have limited effectiveness in suburban landscapes because hunter access to geese may be restricted by local ordinances, public opposition, and safety concerns. Non-lethal wildlife control techniques have greater public acceptability than lethal control techniques, especially in suburban areas. However, non-lethal control techniques such as repellents (Cummings et al. 1991, 1995; Blackwell et al. 1999), frightening devices (Heinrich and Craven 1990), and hazing (Castelli and Sleggs 2000) have variable and relatively short-term effectiveness. Loker et al. (1999) found that residents' acceptance of invasive and lethal methods to resolve wildlife problems in suburban areas was strongly related to concerns about nuisance and economic damage.
One control strategy for geese that has been relatively successful and acceptable to the general public is embryo destruction. Destruction of eggs via puncture or spraying with oil (Christens et al. 2000) terminates embryo development. However this does not cause the female to abandon the clutch and re-nest during the same breeding season. Therefore, egg destruction provides a potential and acceptable means for population reduction of geese at the community level. There is also increasing evidence that non-nesting females and pairs of geese who nest unsuccessfully, molt migrate from southern breeding areas to northern Canada during mid-summer for replacement of their flight feathers, from at least 26 eastern and central states (Abraham et al. 1999). A pilot study conducted in New York during summer 2000 indicated that 80% or more of non-nesting geese migrated north out of New York (Swift and Curtis 2001).
We plan to reduce resident suburban Canada goose abundance through embryo destruction, and assess movements and behavior for geese whose nests have failed. The study will be conducted at suburban sites experiencing high densities of resident Canada goose populations in NJ, NY, VA, and WV. Two locations will be randomly selected in each state as a treatment area and a control sites. Pairing of areas within each state and across state boundaries will be based as much as possible on site land use and habitat similarities.
In the first year, geese at both the control and experimental sites in each state will be rounded-up during the molt and a representative sample of randomly chosen adults will be fitted with easily identifiable neckbands. In addition, a group of 10 neck-banded geese will also be fitted with satellite transmitters to monitor long-range movements. Another 20 neck-banded geese will be fitted with standard VHF transmitters to monitor local movements. Efforts will also be made to monitor and record nest productivity and success for as many neck-banded and radio-tagged geese as possible.
At each of the experimental sites during the second year, nests will be located for geese with VHF transmitters and efforts will be made to locate as many nests of neck-banded geese as possible. For each nest located, eggs will be destroyed and goose behavior will be monitored. Movements of geese whose nests failed and were fitted with transmitters will be monitored weekly either by satellite tracking, or more frequently via hand-held, vehicle, or aircraft tracking.
To determine if suburban goose abundance was reduced at each treatment site by embryo destruction, a randomized block design will be conducted comparing the proportion of banded geese to non-banded geese between and among the control and experimental sites for each state, and across states. Geese will continue to incubate their eggs if the embryos are destroyed until it is too late to renest. During subsequent years, fewer geese may return to treatment sites because the number of young geese hatching was reduced. Movement data will be analyzed and reported for radio-tagged geese that failed to nest successfully and were wearing transmitters and/or neckbands.
Measurement of Progress and Results
Outputs
- Develop standardized research protocols and deer damage assessment techniques for states across the Northeast.
- Provide a forum for research ideas, peer review, and coordination of projects.
- Sponsor symposia and technical sessions at appropriate professional meetings.
- Analyze wildlife damage survey results and publish peer-reviewed journal articles.
- Ascertain the acceptability and potential adoption of new wildlife management tools and programs via human dimensions surveys.
- Develop a model implementation plan for community-based white-tailed deer and Canada goose management
- Provide outreach information for extension specialists, agency staff, and community leaders in the form of booklets, fact sheets, videotapes, and a web site.
Outcomes or Projected Impacts
- Reduce deer-vehicle collision rates and plant damage to levels identified by participating communities that implement an integrated deer research and management program.
- Stop resident Canada goose population growth and reduce the length of time geese are present during summer to cause turf-related damage complaints at parks, athletic fields, corporate complexes, and for residential lawns in communities that implement
- Have growers for selected commodities (fruit, vegetables, ornamentals) adopt integrated crop management practices for effectively mitigating deer damage.
- Increase scientific understanding of socially acceptable methods for resolving wildlife conflicts.
- Agency wildlife managers will adopt new procedures for assessing deer damage and mitigating conflicts in participating communities.