Initial tests on upper Ruby Valley elk have turned up a higher rate of brucellosis than officials and ranchers were expecting.
Out of the 100 elk captured south of Alder last month, 12 tested positive for brucellosis antibodies, said Neil Anderson, biologist with Montana Fish, Wildlife and Parks in Bozeman.
“I was a little bit surprised at how high it was,” Anderson said.
The elk were captured the beginning of February as part of a five-year study to try and find out more about brucellosis, which is a disease that can be found in elk, bison and cattle and can cause animals to abort their fetuses. The captured elk were radio collared and given a blood test.
Even though 12 of the animals tested positive for the brucellosis antibodies, it doesn’t necessarily mean they have the disease, Anderson said.
“The animal could have been exposed and the antibodies actually expelled the bacteria and the animal was never infected,” he said.
Similar to humans, animals can be exposed to a disease and fight it off. These animals would have antibodies for the disease in their systems but no longer be carriers of the illness.
Anderson is having other tests done to the positive samples to help give him an idea of whether or not the 12 animals are actual carriers of brucellosis.
The only way to positively test whether or not an animal has brucellosis is to kill the animal and test it’s tissue, he said.
This is the first time FWP officials have trapped and tested live elk in the upper Ruby Valley. They’ve collected samples from hunters, but those samples have provided limited information, Anderson said.
The hope is the five-year study will give FWP officials an idea of the extent and range of brucellosis in elk, he said. It could also give scientists a better idea of how the disease affects animals and gets transmitted.
Along with the blood samples, Anderson and his crew put vaginal implants in the cow elk, which will emit a special signal when they have a calf.
The normal calving season for elk is early to mid-June, he said. The brucellosis bacteria is thought to be transmitted through the after birth of an animal.
The implants will tell the scientists when a cow has her calf early, which would be an indication it was aborted, Anderson said.
The goal is to get to the aborted calf before predators clean any potential samples up, he said. Crews are already in the field trying to keep track of the elk.
“We’re going to try and find those spots and that’s going to be difficult,” Anderson said. “Around mid-June is when they start having calves, but the abortion window is anywhere from now until then.”
Ranchers in the area figured there was brucellosis in the elk, but didn’t expect the initial test results to be that high.
“It’s a higher number than we thought there would be,” said Alder rancher Dan Doornbos.
Doornbos is in the Montana Department of Livestock’s designated surveillance area, which means he has to test his herd for brucellosis on a regular basis. His herd monitoring plan is to test every year.
“My big question is are they going to do anything about it in the elk or are we going to just have to live with it,” Doornbos said. “It’s a problem and I’m wondering how they’re going to manage it.”
Over the past couple of years, pressure from an increasing number of wolves have pushed elk lower and now they’re in the valley bottoms where they didn’t used to be, he said.
“We see a lot more elk down here in the valley now than were ever here before,” Doornbos said.
Still, he’s able to keep his cattle separated from the elk during the elk’s calving season, which is crucial.
Anderson’s study is planned for five years, pending funding. Once the elk calving season is over, he anticipates the agency will release a report discussing their findings.