March 23, 2002 Rocky Mountain News (Denver, CO) by Jeff VerSteegChronic wasting disease (CWD) is one the most difficult challenges the Colorado Division of Wildlife has ever faced.
Veteran wildlife managers who have spent decades building Colorado's wildlife populations have had to kill hundreds of deer as they work to stem the spread of the disease. It's the grimmest task they've faced in their careers, and the last thing they want to do.
They also recognize, however, that reducing the deer herd in a portion of northeastern Colorado is an essential part of the agency's overall program to combat CWD. The division has two key goals. First, we must do everything we can to keep the disease from spreading to wild populations in other portions of Colorado and other states. Second, we want to reduce the prevalence of CWD in the Colorado endemic area to less than 1 percent. Accomplishing these seemingly straightforward goals will likely take years, perhaps decades.
There is no magic cure and no easy solution to chronic wasting disease. But taking no action is irresponsible, and hoping that somehow the disease will go away on its own is wishful thinking
If we take no action, the disease will spread. Within several decades, deer populations could undergo a dramatic decline. We would be abrogating our responsibility as wildlife managers, leaving future generations of Coloradans to deal with the consequences of chronic wasting disease.
Some groups, including animals rights activists, want the division to kill no deer. Others, including captive elk breeders and some sportsmen, have demanded that the division kill all the deer in northeastern Colorado. We believe a more moderate course that concentrates our efforts on areas of infection is the most prudent, responsible approach.
Chronic wasting disease is a fatal neurological disease of deer and elk found in wild herds in northeastern Colorado and southeastern Wyoming, and in a small portion of the Nebraska panhandle. In Colorado, we have detected the disease in about 5 percent of deer and less than 1 percent of elk within an endemic area covering about 8 percent of the state. The highest prevalence rate of 10 percent to 15 percent has been found in mule and white-tailed deer along the northern Front Range extending from Fort Collins into central Wyoming.
To stop the disease from spreading and reduce it's prevalence in wild deer, the division has been selectively culling deer herds in the endemic area. Management plans approved last month by the Colorado Wildlife Commission call for what amounts to about a 20 percent reduction in the deer herd within the endemic area, from approximately 25,000 down to 20,000 deer over 3-5 years.
Hunters killed more than 1,000 deer in the past year, and hunting will continue to be a primary management tool. Division officers and biologists are also culling deer herds, especially in those areas where disease prevalence is highest. However, most of the necessary reduction will be accomplished through hunting.
In Game Management Unit Nine north of Fort Collins where the number of infected deer is highest, the division - in cooperation with Wyoming officials - is conducting a management experiment to determine if a lower density of deer will result in lower disease prevalence in that herd. The goal is to reduce the herd in this unit by half to about 1,000 deer. An area just across the border in Wyoming, where the rate of infection is just as high, will not be reduced so that it can serve as a control. Once the reduction is completed, disease prevalence will be evaluated to determine how effective this approach has been.
On the periphery of the endemic area, wildlife officials are using a different management strategy. Instead of killing large numbers of deer, the focus is on removing specific small herds where diseased animals have already been found. The goal of this selective culling is to stop the disease in its tracks before it spreads to new areas, and perhaps to eliminate it in places where the prevalence is below 1 percent.
Most deer in these areas have very small home ranges allowing selective culling to be an effective tool. As we continue our management efforts, we should be increasingly successful in identifying those areas of highest infection.
We know that there are no easy or quick fixes for controlling this disease. There may never be. However, we truly believe that our management efforts must continue if we are to achieve the goals of containing CWD and reducing its prevalence.
NOTES: Jeff VerSteeg is the Colorado Division of Wildlife's terrestrial wildlife manager.;