WDNR CWD Management Plan a Practical Impossibility: Financially and Politically Motivated Objectives A landowner's opinion by Anthony C. Grabski, Ph.D. May 1, 2002
The recent discovery of CWD in South West Wisconsin's deer herd has become a major concern for sportsmen, wildlife viewers, outfitters, business owners, private landowners, and government agencies responsible for funding and developing a disease management plan. However, the current proposal to randomly and extremely cull the deer herd in a 415 square mile section of Dane and lowa Counties is primarily motivated by financial and political objectives without due consideration to existing scientific and statistical facts or long term health of the deer population. First lets look at the numbers used in the current proposal. The DNR sampled 345 deer statewide last year including 82 at Mount Horeb. Three positives were found in the Mount Horeb samples. These results prompted the sampling of another 516 deer from the Mount Horeb area and an additional 11 positives were identified. These numbers have been inaccurately manipulated to amplify the incidence rate and were calculated at 14 out of 516 or 2.7% were positive. The correct calculation is 14 out of 598 or 2.3% were positive. Additionally, as in any immunohistochemical test, false positives are possible due to cross reactivity with uninfected tissue and subjective interpretation of the results. If only 2 of the 14 positives are incorrect, the incidence drops to only 2%. I would like to see the raw data from these tests. The remainder of the 345 deer statewide sample, 263 deer, were taken at numerous iocations across the state, but no other area was sampled as heavily as Mount Horeb. Therefore, with an incidence of oniy 2.3% from a sample size of 598 it is possible that CWD exists in other areas of the state, but statistically the minimum number of deer tested at a given location would need to be greater than 50 or the disease could go undetected. The remainder of the state must be adequately sampled and tested in order to obtain accurate CWD distribution and prevalence figures. Although the origin of CWD is uncertain, the disease was discovered in captive herds during the early 60s near Ft. Collins, CO, and in 1981 CWD was detected in wild populations in Northeast CO. Since that time only 100 cases of clinical CWD have been identified in northeastern CO and southeastern WY (Miller, et al., 2000). The CO deer and elk herd has not collapsed over the past 20 years, and there is no evidence that people who eat meat from infected deer assume additional health risks. The goal of the Colorado Wildlife commission is to reduce the incidence of CWD to <2% of the population. They have written, developed, and are implementing several management plans throughout their state. I have been in direct contact with several CO Division of Wildlife Officials including Dr. Mike Miller, Wildlife Veterinarian and CWD expert, and Terrestrial Biologists Mark Vieira and Janet George, coauthors of Colorado's Big Thompson Deer Management Plan. The Big Thompson Plan states as one of its 3 management alternatives to reduce the deer herd in an infected area by 90%. While this plan might possibly eradicate the disease, the process of reducing the herd to the point where CWD is eliminated is certainly an impractical possibility for several reasons. Quote: CWD eradication from the D-10 herd and surrounding environment is probably infeasible given the uncertainties and complexities of its epidemiology. To reduce the population to such a low level would require dramatic supplementation of hunter harvest with intensive and broad scale CDW culling efforts. However, private land, parks, and open spaces would always harbor irremovable deer populations in excess of 10%. Even if possible to accomplish a reduction of this scale on surrounding lands would require a huge investment of resources and be totally unpalatable to the general public. Such a large-scale manipulation of a population would also presumably cause broader ecological impacts. While the initial herd reduction would cause an immediate increase in recreational opportunities, the reality of sustaining such a small herd for long-term would result in greatly reduced opportunities for hunter harvest. This option reaches far beyond the reasonable terms for management set forth in CWC policy. Instead of the unreasonable WDNR plan to randomly reduce the population, CO has adopted the strategy of adaptive management (Walters and Holling, 1990) as the most reasonable for dealing with a situation with so many unknown components. This plan involves implementing several experimental management plans simultaneously with projected objectives that can be changed quickly in order to enact new tactics that have proven successful in small-scale management experiments. The management model experiments include random and selective population adjustments by hunting and sharp shooter culling, buck doe ratio adjustments, and age ratio adjustments. Mathematical models indicate that aggressive selective culling of infected animals is more likely to reduce the prevalence than random culling. Why then is the WDNR pushing ahead with proposed mass random culling of deer in the infected area? Why do they propose to artificially decimate and collapse the local deer population in order to gain a few tenths of a percent of CWD control when the disease itself could only possibly cause this level of decline? (Current WDNR estimates indicate at 50 to 1 OO-deer/square mile with a 90% kill rate 18 to 36,000 deer would need to be killed.) Why have they fostered scare tactics through selective presentation of information by the media? The reasons are best quantified in dollars and justified politically. Although mass random culling is almost certain to fail as a means to eradicate CWD in Wisconsin, huge sums of money will change hands and funnel their way into a failing state budget. Governor McCallum has asked congressional delegates to request $18.5 million in Federal aid to support the fight against the disease and the DNR agencies have requested an additional $4 million in state money. In addition, the mass deer slaughter will be a very visible, quick and easy attempt at a solution. This 'sky is falling response' will satisfy politicians in other areas of the state and out-of-state hunters who pour money into the economy each fall in order to deer hunt in Wisconsin. The random culling management plan will show that however wrong, 'something' is being done about CWD, but this solution is primarily designed to quickly justify federal funding requests, to calm a political storm in other areas of the state, and to prevent mass exodus of out-of-state hunters and their dollars. The plan proposed here tonight will not improve the long term health of the deer herd, does not give adequate consideration to existing statistical and scientific methods and has not outlined a comprehensive policy to address CWD throughout Wisconsin. References 1. Colorado Wildlife Commission. (2001) Colorado Wildlife Commission policy on CWD. 2. Gross, J. E. and Miller, M. W., (2001) CWD in mule deer: a model of disease dynamics, control options, and popuiation consequences. J. Wi/dlife Management, 65:205-215. 3. Miller, M.W. and Kahn, R.H., (2000) CWD in Colorado deer and elk: recommendations for statewide monitoring and experimental management planning. Colorado Div. of Wildlife, Ft. Collins, CO. 4. Walters, C.J. and Holling, C.S. (1990) Large-scale management experiments and learning by doing. Eco/ogy71: 2060~ 2068. 5. Vieira, M. and George, J. (2001 ) Big Thompson deer herd management plan ,
