Chronic-wasting study bodes ill for elk herds
The New West / By Todd Wilkinson | 0 comments
Part 7 in a series on wildlife diseases in the Greater Yellowstone � Ed.
Chronic wasting disease is notorious for leaving no survivors.
Depending on which member of the deer family it infects and kills by turning victims� brains into sponge-like mush, CWD has been called �mad deer disease� or �mad elk disease.�
Mercilessly lethal, CWD is not only incurable, but the associated rogue proteins, called prions, that cause mortality leach into soils and persist as a disease menace long after dead animals have decomposed on the ground.
Specialists in epizootic diseases say that if an outbreak of CWD occurred in areas where mass numbers of wildlife congregate, the resulting �ecological disaster� would be difficult to contain and clean up.
In 2007, then-Wyoming Game and Fish Department Veterinarian Terry Kreeger made a pronouncement about CWD to the Casper-Star Tribune that caused professional colleagues who make their living thinking about wildlife health issues to gasp.
�Right now,� Kreeger said, �there�s no evidence that a severe reduction of deer and elk will occur [if CWD reaches populations of those animals in Wyoming]. In fact there�s some evidence to show that it will not have any effect on populations, but we expect it does to some degree.�
Kreeger, in essence, was trying to defend artificial feeding at the National Elk Refuge and 22 feedgrounds operated by the state of Wyoming.
Last month, the findings of a new study � peer-reviewed by scientists and published in The Journal of Wildlife Management � cast serious doubts about Kreeger�s assertions.
The study by lead author Ryan J. Monello, a researcher with the National Park Service, and five colleagues in ecology and veterinary medicine examines survival and population dynamics of free-ranging elk in Rocky Mountain National Park of northern Colorado. [Read pdf of study at JHNewsAndGuide.com].
Two hair-raising conclusions: Destroying animals didn�t stop disease progression. And once CWD arrives, mortality is likely to outpace reproduction, resulting in population declines.
Those findings are consistent with those in another study on CWD soon to be released by University of Wyoming doctoral student Malia DeVivo. Her conclusions are expected to paint a dismal outlook for infected mule deer in the southern part of Wyoming, where CWD is decimating some mulie herds.
Critics say these studies are damning illustrations of how Wyoming�s disease management positions are radically out of step with widely held scientific facts. They say it underscores concerns that the CWD danger posed to huge numbers of dispersing elk in Greater Yellowstone is far more problematic than state officials, justifying artificial feeding, are willing to admit.
For comparison�s sake, brucellosis is not �population limiting.� Beyond causing cow elk to abort first pregnancies, it does not typically prevent subsequent successful pregnancies, and it does not kill infected adult animals. CWD, however, is always fatal.
�The Monello journal article indicates that when CWD gets established in an elk population, even after the researchers killed the known infected animals in Rocky Mountain National Park, more elk continued to get the fatal disease,� says Lloyd Dorsey of the Greater Yellowstone Coalition.
He notes the Park Service recognizes that dense concentrations of elk, like those on the elk refuge and Wyoming�s 22 elk feedgrounds, leave animals more susceptible to higher rates of deadly disease.
While Rocky Mountain National Park has densities reaching 115 elk per square kilometer, the densities of elk on the refuge and Wyoming feedgrounds are orders of magnitude greater, literally thousands of elk per square kilometer, Dorsey says.
�This very sobering research in Rocky Mountain National Park should serve as a warning to federal and state wildlife agencies in western Wyoming to do what they can now to avoid such an awful scenario,� he said. CWD is now only miles away from the elk refuge and feedgrounds, he added.
Any day, the Bridger-Teton National Forest is expected to announce whether it will allow Wyoming to keep operating its Alkali Creek elk feedground on national forest land in the Gros Ventre Mountains.
Dorsey, joined by a growing legion of professional wildlife scientists, disease experts and conservationists, cites the expanding body of knowledge about CWD as proof that artificial feedgrounds in Wyoming need to be re-evaluated and targeted for closure.
�Since CWD isn�t here yet, we are positioned well to phase out winter feeding and try to mitigate the effects before it arrives,� Dorsey says.
