A Case-Based Decision Analysis of Urban Deer Management Strategies G. Kent Webb San Jose State University

1. A Case-Based Decision Analysis of Urban Deer Management Strategies G. Kent Webb San Jose State University April 25, 2011 Headline News - CNN

2. Cayuga Heights, NY and Solon, OH have generated the most news Solon Police Deer Killed by Motor Vehicles 2004-2010 “After five years, $807,325.55 dollars, and the massacre of nearly 1,600 deer, Solon has witnessed rebounding deer populations, as predicted.” SolonDeer.Blogspot.org “Let's put this issue on the ballot for a vote, join us on Saturday, April 16th”

3. Communities have responsibility for Urban Deer Management in the U.S., subject to some state regulations on hunting or disposal of deer. Overabundance: deer populations declining in western states and Maine Craig, Colorado

4. It is one of the most contentious local decisions Research: What are the cities doing? Data Collection: Google Alert set up to scan the internet every day for 10 months (July 2010 through April, 2011). Collecting about 50 news or other articles every day on the term “deer”. Also standard Google Search. Cleveland, Ohio

5. Many local decision makers report using the internet to collect information Given the explosion of information on the internet, it is increasingly difficult to find relevant information

8. Decision Approaches Most decisions, 90%, are discussed in city council meetings Attracts proponents and opponents Sometimes a Deer Committee is formed Of six communities conducting surveys, 4 were links on the community website, 2 were mailed surveys Internet links also attract proponents and opponents Even with mailed surveys, proponents and opponents are more likely to respond Discussions become polarized while many are indifferent In some cases 30 percent of residents report feeding deer Majorities both favor and oppose a deer management in reporting cities. (Diverse goals, conference speaker Alberti)

9. Surveys of Deer Often discussed, but dismissed as too costly Options discussed: Aerial surveys using infrared Driving around surveys (not as accurate) What is the appropriate number? The biological carrying capacity of a suburban environment has been estimated at 100 deer per square mile. How many deer are wanted? Only one city reported poor deer health, this was from broken bones

10. Example Deer Map Using Citizen Input, supported by Google maps and forms Cities such as Oxford, MS using citizen input for tracking Effort to engage the public: conference speaker Lindsey, search for stakeholders

15. Information on Deer Management is organized into a searchable text database at www.DeerFriendly.com Urban deer management portal

16. Fencing: A Key to Suburban Environmental Design Only a few communities discussed fencing ordinances that can be used to control deer density and protect plants. Using publically built fences for large areas is expensive For transport, fencing can focus on highways Fencing ordinances significantly impact the long-term ecology Perimeter fencing has cut our local deer herd in half Wildlife permeable fencing and corridors can mitigate negative impacts A southern California community with 15 foot setbacks complains of too many deer

17. Deer Vehicle Collisions (more details on transportation page) Weight and size is correlated to increased damage costs and risk of injury. States engaged in breeding larger deer for hunters increase transportation cost and risk Most deer injuries to drivers are related to secondary collisions, the driver swerves to avoid the deer. Education has been shown to reduce risk. Female drivers have been shown to be at increased risk of injury.

18. Cost effective methods for reducing transportation risks and costs related to deer (a 2007 study), Montana Department of Transportation in cooperation with U.S. Department of Transportation Clearing vegetation around roads provides the highest cost benefit Seasonal warning signs had a positive benefit, accident probablity is much higher during the rutting season. Animal detection systems had a positive benefit Reflecting systems were too costly Culling is found to have a positive benefit if the area is not open to deerimmigration Sterilization and relocation were costs were too high, assuming no immigration

19. Decisions Based on Deer and Lyme Disease Example comment: “…’there is a direct correlation between the number of deer and the number of infections.’ Sullivan explained thatticks feed off the deer, infecting themselves with the disease. They then end up in the grass where they can be transferred to humans. “ - Michael Sullivan, Medfield Massachusetts Town Administrator, “Medfield to ‘cull the herd’ with archers to combat the spread of Lyme” Medfield Press, Online, February 22, 2011 “Deer may carry small numbers of the spirochete that causes Lyme disease but they are dead-end hosts for the bacterium. Deer cannot infect another animal directly and no deer hunter has acquired the disease from dressing out a deer. Infected ticks that drop from deer present little risk to humansor other animals since the ticks are now at the end of their life cycle and will not feed again. Deer don’t carry Lymedisease. A tick infected with the disease does not transfer Lyme to other ticks on the deer.” - Michigan Department of Natural Resources

20. Center for Disease Control’s (CDC) Website In studies on islands, removing all deer greatly reduced the number of ticks. Studies in coastal locations found that reducing the number of deer generally corresponded with decreased numbers of ticks. However, the level of deer reduction needed to substantially reduce the risk of human tick bites or break the Lyme disease cyclewas not established. A study in mainland NJ found that reducing the number of deer did not correspond to decreased numbers of ticks or reduced cases of Lyme disease. However, this study may have been too short or the reduction of deer insufficient to demonstrate an impact. Kirby Stafford, Connecticut Chief Entomologist: “Scientific field research demonstrates that reducing deer below 10 to 12 per square mile provides a satisfactory target for managing tick numbers and Lyme disease.” - Not supported by scientific literature , focused on ticks, measurement questions..

21. "the scientific evidence as I’ve reviewed it, without any preconceived notion or political agenda or any other agenda, does not support the notion that tick numbers and Lyme disease risk are strongly correlated with deer numbers, and the data do not suggest that if you manage deer by hunting, you’ll reduce the number of Lyme cases.”  Dr. Richard S. Ostfeld, Disease Ecologist, Ph.D., University of California. Author of numerous studies on Lyme diseae and author of “Lyme Disease: The Ecology of a Complex System (2011) it would be more effective to parachute opossums into the area

22. Biodiversity and Disease Risk: The Case of Lyme Disease  Richard S. Ostfeld and Felicia Keesing Conservation Biology Vol. 14, No. 3 (Jun., 2000), pp. 722-728 In North America, the most competent reservoir host for the Lyme disease agent is the white-footed mouse … Analyses of states and multistate regions along the east coast of the United States demonstrated significant negative correlations between species richness of terrestrial small mammals (orders Rodentia, Insectivora, and Lagomorpha), a key group of hosts for ticks, and per capita numbers of reported Lyme disease cases, which supports our "dilution effect" hypothesis. A positive correlation between per capita Lyme disease cases and species richness of ground-dwelling birds supported this hypothesis, which we call the "rescue effect." 

23. Climate, Deer, Rodents, and Acorns as Determinants of Variation in Lyme-Disease RiskOstfeld RS, Canham CD, Oggenfuss K, Winchcombe RJ, Keesing F (2006) Climate, Deer, Rodents, and Acorns as Determinants of Variation in Lyme-Disease Risk. PLoS Biol 4(6): e145. Indices of deer abundance had no predictive power, and precipitation in the current year and temperature in the prior year had only weak effects on entomological risk. The strongest predictors of a current year's risk were the prior year's abundance of mice and chipmunks and abundance of acorns 2 y previously. In no case did inclusion of deer or climate variables improve the predictive power of models based on rodents, acorns, or both. We conclude that interannual variation in entomological risk of exposure to Lyme disease is correlated positively with prior abundance of key hosts for the immature stages of the tick vector and with critical food resources for those hosts.

24. System to apply tick control to deer January 11, 2011 Arkansas Southwest News-Herald  ARS researchers have developed new cattle fever tick control measures including this one that automatically applies a pesticide-impregnated neckband to deer ... The Agricultural Research Service (ARS) tackled the tick problem by developing a device called the 4-Poster Deer Treatment Bait Station. This is essentially a corn-filled bin with paint rollers on its four corners. The ARS scientists have since refined their deer treatment station, creating a new system that automatically applies a pesticide-impregnated neckband to wild deer as they feed. The collars can be detached remotely once they've stopped working.Gibson Island, Maryland, which is a private, resident-owned community, purchased 15 of the devices and deployed them around their community for five years, and achieved at least 77 percent control of the ticks that carry Lyme disease and human monocytic ehrlichiosis, both serious human health problems.

25. The Four Poster System Some citizens would pay for the right to legally feed the deer, a possible source of funds for this system

26. No human injuries were reported from deer culls. Safety concerns are commonly an important issue. Lowest cost: -$25; hunters will pay. Deer have been wounded.

27. Contraception Products: Gonacon, Spayvac Researchers working to achieve reduced number of reapplications. Testimony from Allen Rutbery, professor at Tufts Universities’s Cummings School of Veterinary Medicine  The vaccine produced noticeable results in each trial, Gutberg said. On Fire Island, less than 20 percent of does that were treated produced fawns the following year. This trend was accompanied by a 50 to 60 percent decline in the local deer population during an approximately 10-year span. On Fripp Island, the one-shot vaccine had produced an 80 to 90 percent drop in fawning rates. Rutberg said the costs of deer birth control were not inconsiderable. While remote darting of the deer cost only about $80 in the Fire Island program, capturing each deer for vaccination and tagging on Fripp Island cost more than $500.

28. Officials Work To Spay Deer To Reduce Their Population « CBS Baltimore Feb 14, 2011 ... Spaying to control the population of domesticated animals is being given a try in the wild.  Contraceptive darts have been tried before in Maryland but they must be administered once a year.  A biologist with a doctorate and a national reputation as a deer sharpshooter, can sterilize five to seven deer a day vs. shooting 10 to 15 a day. In July 2007, Cornell University began a five-year, $500,000 deer management plan that used hunting and surgical sterilization to reduce the campus herd by 75 percent. Results should be out soon.

29. If sterilization and contraception cost about twice as much per deer as lethal methods, And non-fertile does prevent in migration of new does, Then sterilization and contraction become cost effect in just a few years This approach requires management and planning

30. Austin, Texas Decision: Not to Cull, Focus on Education Thank you Texas Parks and Wildlife

31. Conclusions The benefits of culling deer to reduce Lyme disease appear to be significantly over estimated. Diverts resources from a spreading health risk Bad public relations for wildlife Connecticut goal of 10 deer per square mile not support by research Larger deer are correlated with more collision damage. Efforts to increase deer size for recreational hunters comes at a cost to society not taken into consideration Analysis related to culling often ignores immigration Over estimates the benefits of lethal versus non-lethal methods. Sterile does will defend local territories, reducing in migration. Long-term design solutions typically not considered fencing ordinances, corridors, clearing vegetation around roads, education, which deer should be culled or sterilized

32. “Killing deer is like mowing the grass” - Biologist with an urban deer management company www.DeerFriendly.coma not for profit