'Dr. Deer' Addresses Sportsmen on CWD and Herd Culling

On Saturday, July 13, Dr. James Kroll presented a seminar about deer and chronic wasting disease to more than 100 sportsmen at the Hollidaysburg Middle School auditorium.

Kroll is known as "Dr. Deer" because of his extensive work in the deer research and deer management fields. Kroll's credentials include being professor emeritus at the Institute of Whitetail Deer and Management, at the Arthur Temple College of Forest and Agriculture at Stephen F. Austin University, and being a PhD. graduate of Texas A&M University.

His focus has centered on habitat management techniques and whitetail research and management. He has authored several hundred articles about deer research and management that have appeared in both popular magazines and scholarly research journals.

Kroll was introduced by Rodney Swope, vice president of the local deer interest group, Sportsmen for the Future. Before introducing Kroll, Swope said that Sportsmen for the Future's mission is to stop the non-selective culling of wildlife, especially deer, for experimental purposes. He noted that his group opposes the Pennsylvania Game Commission's plan to cull large numbers of deer in the area without proof that this culling will bring results.

He stated that Sportsmen for the Future is pushing for research, not culling. The group will fight for wildlife and wildlife-related businesses. He also lamented that the Pennsylvania Game Commission will not listen to sportsmen.

Also prior to Kroll's presentation, State Rep. Jim Gregory briefly addressed the group. He stated his support for Sportsmen for the Future and for the deer-hunting tradition.

When Dr. Kroll began his presentation, he noted that he has worked with deer, has hunted them, and has helped manage them throughout the United States and Canada for the past 48 years. He noted that as a Texan, he has a special affinity for Pennsylvania because a number of Pennsylvanians fought at the Alamo. He observed that he still spends about seven months a year doing deer research and management and five months trying to harvest deer. During his introduction, he told the audience he would present scientifically proven facts.

"I am a scientist," Dr. Kroll said. "Scientists use the 'scientific method' to disprove hypotheses when searching for facts. He did not support the contention that states, 'If I hadn't believed it, I wouldn't have seen it.'"

Basic Facts

Kroll then presented basic facts concerning chronic wasting disease (CWD). He reviewed for sportsmen that CWD is a Transmissible Spongiform Encephalopathy that causes its host's brain to become sponge-like. CWD is caused by misfolded proteins called prions. When asked three times during the question-and-answer session at the end of his program whether Dr. Frank Bastian's research stating that prions were a symptom and not a cause of CWD, Kroll patiently noted that Bastian's research has been discredited and that no other scientists were ever able to replicate it. He also noted that Bastian has lost his research position at Louisiana State University.

Kroll noted that CWD first appeared in Colorado in 1967 in research pens in deer and elk but that no one knows how it originated. He observed that it has spread to various other states during the past 50 years, including Pennsylvania. He stated that CWD exists in white-tailed deer, elk, moose, and even Scandinavian reindeer. It does not exist in people. He noted that it has never been demonstrated that it can spread to humans.

He mentioned an often-quoted study of macaques being infected by CWD that suggests humans could contract the disease. He said that this study has never been published and that other scientists have proved that the chances for humans to acquire CWD is between slim and none because deer and human prions are different. CWD has never been found in a human who has eaten venison. He quoted an observer who said," If I wanted to destroy [deer] hunting, I would convince hunters that venison can spread CWD to humans. "Kroll added that livestock is not affected by CWD either.

Dr. Kroll noted that CWD is not a density (of deer) dependent disease; rather it a frequency (of contact with prions) dependent disease. Deer can acquire prions from the soil, from the urine and feces of other deer, and from direct contact with another deer's saliva. He noted that fetal transmission, predators, and scavengers can spread it. Plants, however, do not spread CWD. He observed that there are also unknown causes where CWD just seems to pop up. One thing researchers still do not know is how many prions are required to infect a deer with CWD. He said that it usually takes about three years for CWD to be able to be detected in an infected deer.

He did note Professor Nicholas Haley's research that observed that it takes 133,000 gallons of urine for CWD to be able to be detected in the urine. This would negate the necessity to ban urine-based deer lures in an effort to prevent the disease.

'Frankenstein Experiments'

Kroll related that there are "Frankenstein Experiments" out there that muddy actual scientific research. One was that deer were given injections of 250 milliliters of infected blood and that others were orally inoculated with 50 milliliters of saliva. Kroll wondered how many wild deer are injected in this manner. He noted a "Snake Oil and Irresponsible People" experiment where a Minnesota "researcher" said he could develop a field test for CWD for hunters. His research garnered him $1.8 million and produced nothing. Kroll got a laugh when he said that some "experimenters" actually warned hunters that CWD could come from zombie deer.

Some other facts that Kroll presented included one that infected deer that have died have not necessarily died from CWD. He stated this as "morbidity does not equal mortality."

Another fact is that CWD is not a wild deer or captive deer disease: it is a deer disease.

Another fact is that EHD is killing many deer.

One thing that Kroll repeated during his two-hour presentation is that no present control measures or eradication measures have proved to stop the spread of CWD. He said that even if every deer in an area were shot and removed, CWD prions would remain in the soil. Other deer would move in to the vacant area and could become infected. Therefore, large-scale culling programs are ineffective.

One surprising statement he made is that supplemental feeding, which is now discouraged in Pennsylvania, could possibly be helpful in the battle against CWD since it could spread deer out.

Wisconsin Experiences

Kroll then spoke specifically about his experiences in Wisconsin. Though not known how CWD first came to Wisconsin, one theory was that infected material was sent to a Wisconsin research facility and that the first cases of CWD were found within 14 miles of the facility in 2002. He noted that although Wisconsin Department of Natural Resources had its heart in the right place, its initial plan of deer eradication involving increased harvest limits and culling by sharpshooters did not work. He mentioned that even spotted fawns were shot. More than 172,000 deer were killed in CWD zones by 2012. The cost was $37.3 million, of which only $25.8 million could be accounted for. The cost of a culled deer jumped from $478 per deer the first year to $768 the next year. Wisconsin's deer eradication plan lost credibility with hunters and ultimately the hunters' support. It seemed to be a "cash cow" for the agency.

In 2011, Wisconsin Gov. Scott Walker contacted Dr. Kroll to come to Wisconsin to help as its first deer trustee. Kroll and his research team, which included Dr. Gary Alt, required complete independence from political forces to evaluate the plan and to make changes. In his team's first report, he noted that the state's eradication plan had not achieved its goals. "You can't kill more deer if deer don't exist there." The team stated that a way for deer managers to lose credibility is by trying to manage deer by using a population model. He noted that trying to estimate a deer population is next to impossible.

The team recommended that "boots on the ground and public involvement in deer and CWD management were required for success. Using County Deer Advisory Committees and involving landholders and stakeholders was necessary." The team noted that goals of increasing, decreasing, or stabilizing deer populations in various areas were necessary.

He noted that managers needed to start with historical data, examining animal health, and considering demographics. For instance, managers needed to understand the social tolerance for deer in specific locations, often considering the number of deer-car collisions in the area.

Kroll then repeated the team's recommendations: Establishing boots on the ground, using DMAP programs in specific areas, and using relatively small county-based management areas. This was implemented in 2014. He noted that DNR members were unhappy at first about these plans and constraints but that as time passed DNR members recognized the value of the plan.

He noted that today Wisconsin, which had been compared unfavorably with Illinois which chose a severe culling plan, compares favorably and that all but the four most heavily infected Wisconsin counties produce few deer infected with CWD. He noted that CWD is really a four-county disease in Wisconsin. Even with its eradication plan, Illinois is seeing an increase in CWD and that it has fewer deer than Wisconsin. In fact, he noted that Wisconsin leads the nation in producing Boone & Crockett trophy bucks. Recently, Wisconsin produced 40 percent of the rifle-killed typical B&C bucks, 50 percent of the non-typicals, 20 percent of the bow-killed typical bucks, and 40 percent of the bow-killed non-typicals.

Kroll concluded his formal presentation with the statement that "deer eradication programs have been failures and will be elsewhere if attempted. Deer eradication does not work in combatting CWD."

What Pennsylvania Should Do

When asked during the Q/A session what Pennsylvania should do, Kroll hesitated then observed, "Not what they're doing now (with the planned large-scale culls). The PGC would lose credibility with a wholesale slaughter. The PGC should cooperate with landowners and sportsmen."

He observed that while driving through Pennsylvania he observed serious habitat problems, that extensive habitat work could be done to help the deer."

He stated a concern that in 20 years there might not be much left of deer hunting with the loss of aging hunters and no one to replace them. He observed that it is tough to get young people outdoors, away from their electronic devices.

He did observe that CWD is "probably much ado about nothing, that the whitetails will solve the problem on their own."