Test-and-Removal Pilot Project enters 3rd year
by Wyoming Game & Fish Department
February 9, 2008
(Pinedale) - Wyoming Game and Fish Department personnel trapped 501 elk at Fall Creek and Muddy Creek feedgrounds this past week as the test-and-removal pilot project entered its third year. Of the 300 adult cow elk tested for brucellosis, 36 tested positive for exposure to brucellosis, a disease that infects elk and bison in northwest Wyoming and is a threat to the livestock industry.
The five-year project was one of 28 recommendations made by the Governor's Brucellosis Coordination Team (BCT) in a comprehensive effort to deal with brucellosis in Wyoming. The members of this group were tasked to come up with effective long-term solutions to the brucellosis problem in Wyoming and to come up with new ideas on how to manage brucellosis.
A number of elk also escaped the trap at Muddy Creek after being tested. After all the elk were sorted, collared, ear tagged and had blood samples drawn, 42 elk breached a gate that was wired shut before personnel were able to hold the remaining 70 in the corral. Out of the escapees, four elk tested positive. Those elk will be removed at a later date.
There were 10 trap-related mortalities associated with the operation this year. So far, over 1,000 elk have been processed through the traps in three years with a total of 13 trap mortalities. When handling such a large number of elk, capture mortality is always a possibility. This year's higher mortality was in part due to the largest catch-to-date and also a higher number of adult bulls in the trap.
"We may have met the capacity of our traps and the tolerance of the elk this year," said Game and Fish Director Terry Cleveland. "I'm thankful that our personnel were able to handle the situation efficiently and professionally and minimize injuries and stress on the animals while making sure that no personnel were injured in the operation."
Inclement weather also played a role in the trapping operation this year. Winter storms prevented trapping on the first day's attempt and also made the transportation of elk and blood samples difficult. "We'd like to thank the Sublette County Commission and Frosty Hittle for keeping the roads to our traps open during intense winter storms," said Game and Fish Warden Supervisor Scott Werbelow, who supervised the trapping operation.
Blood from the animals was driven to Laramie to be tested at the Wyoming State Veterinary Laboratory overnight.
A total of 29 seropositive elk, those that were considered most likely to transmit the disease, were transported to a USDA approved slaughter facility in Idaho. The meat from these animals will be donated to the public through the Rocky Mountain Food Distribution Center, which donates to qualified individuals throughout Wyoming. The facility only accepts live animals to be slaughtered for human consumption, so trap
mortalities cannot be processed there.
A final comprehensive report will be published and available to the public later this year. As of this time, the Game and Fish plans to attempt trapping at both of the feedgrounds again this winter. In addition to the removal of seropositive elk, there is also valuable research in brucellosis management evolving from this experiment. Currently, blood samples from captured elk will only show if the animal has been exposed to Brucella abortus, the bacteria responsible for brucellosis infection. Tissue samples were collected from seropositive elk, including trap mortalities. These tissues will be cultured to determine if the slaughtered animals were actually infected and capable of transmitting the disease.
There is other important scientific research that is making use of the biological samples. Fetuses removed from seropositive elk that test culture negative are being used to research how often aborted fetuses are contacted by other elk on feedgrounds. An animal with a culture negative test cannot transmit brucellosis. This research led to the development of the Target Feedground Project. Results of this project have been used to alter feeding techniques on several of the feedgrounds in the region. Brucellosis is a density dependent disease that can be transmitted through contact with birthing tissues and fluids. Lowering elk densities should reduce the chance for contact with these fluids and thereby lower brucellosis seroprevalence.
There is also cooperative research being conducted with the U.S.Geological Survey. Four seronegative elk on each of the feedgrounds were fitted with Global Position System collars to determine risk to cattle producers based on elk locations throughout the year. The research also will investigate how the amount of time spent on feedgrounds correlates to stress levels in fed elk. Increased stress levels negatively impacts immune response in elk, which may increase their susceptibility to disease.
The Wyoming Governor’s Brucellosis Coordination Team outlined the pilot project and complementary research as a critical component of managing brucellosis in wildlife. Brucellosis transmitted to cattle herds from elk caused Wyoming to lose its brucellosis free status in 2004. Wyoming regained its Brucellosis Class Free status in September 2006, however a reservoir of brucellosis remains in western Wyoming’s elk and bison herds. Ongoing research is part of the effort to eliminate brucellosis in wildlife and maintain Class Free status for the state’s livestock producers.
The Governor’s Brucellosis Coordination Team recommended the pilot test-and-removal experiment last five years. Currently, the WGFD plans to expand the project to the nearby Scab Creek feedground in 2009. This feedground is also in the Pinedale Elk Herd Unit. During this test-and-removal experiment no more than 10 percent (about 191 elk) can be removed from the population each year.