A Montana conservation group is petitioning the state to reconsider its management of bighorn sheep, saying the current strategy isolates small populations and places the overall sustainability of the state’s sheep in jeopardy.
The Gallatin Wildlife Association will take its petition to the Montana Fish and Wildlife Commission on Dec. 10. The petition asks for repeal of a single bighorn sheep hunting license for the Greenhorn Range south of Virginia City as well as an overhaul of the state’s sheep management strategy.
Glenn Hockett, association president, said the petition is really about the larger question of Montana’s bighorn sheep conservation strategy, which often manages for small isolated herds and does not recognize the need for genetic exchange with larger populations.
“The permit itself will get all the attention, but the question really is whether we’re managing for viable populations across the West,” he said. “The answer is no, we’re not.”
Hockett cites Montana’s bighorn sheep conservation strategy, which notes a sheep population of 125 as a minimum viable population. That number is far too low, he believes.
“The best available science says we need thousands,” he said. “If you look at Wyoming, they have interconnected bighorn sheep populations of 4,000 to 6,000 animals that are some of the most productive of anywhere.”
Bighorns have a propensity for contracting diseases that cause massive die offs. Once a die off occurs, herds tend to persist in small numbers but never fully recover. Efforts to supplement herds with transplanted sheep have largely proved ineffective.
Domestic sheep and goats are considered the primary means of contracting disease, and one major concern for biologists are roaming bighorns that become infected and transmit pathogens to the rest of the herd. The disease threat is so significant that biologists will not transplant sheep into areas where there is a risk of wild and domestic sheep comingling. Officials have also killed wild sheep that have contacted domestics as a precaution.
Hockett’s group would like to see FWP and public land mangers work on connecting Montana’s populations, and that means removing impediments and risk factors from domestic sheep grazing.
“We’re managing to keep these populations small, and (given disease) that seems rational,” Hockett said. “There are risks to building connectivity but one of the first things to go when you get genetic depletion is resistance to disease. Being genetically connected, I think that’s the only way forward in the long term.”
John Vore, FWP game management bureau chief, recently told the commission that having more connectivity would be beneficial genetically speaking, but mangers must also consider the viability in the face of disease transmission and what will keep sheep on the landscape.
“The discussion has been that many herds are small and isolated or relatively isolated,” he said. “No one is arguing that connectivity with metapopulations wouldn’t be the best,” but Montana’s landscape is not like the vast habitat available in places like British Columbia.
Montana has limited disease-free wild sheep available to transplant and biologists must choose animals from similar habitats. Much is also still being learned about diseases and ongoing research will tell managers more about what diseases are out there and where, he said.
“We have to weigh the benefits against the risk,” Vore said. “I will admit that at Fish, Wildlife and Parks we are being very conservative in our approach to sheep management because there is so much at stake.”
There is also evidence suggesting that bighorns move around more than what was previously believed. Disease transmission and ear tagged sheep showing up in new places are two pieces of evidence that some sheep will travel and bring new genes, and analysis has backed up genetic exchange, he said.
While connectivity might be preferable, Vore noted that transplants also play an important, and potentially less expensive, role in genetic exchange.
Hockett is not against hunting and harvested a bighorn himself in the 90s in the Tendoys when the herd was at about 300 animals. A die-off occurred that winter and after years of a small population hampered by disease, hunters and FWP removed the remaining animals with plans to reintroduce them. Hockett notes his frustration that plans call for a population of about 150 – a number he believes acquiesces too much to livestock interests.
“That’s a recipe for failure,” he said. “I think we’re in denial of what a viable population is, and the science is getting buried in the political mess.”
For the Greenhorn license, the association notes that counts have been below the 125 threshold leading to their request to rescind the license.
But minimum counts alone are not the only criteria when it comes to allowing hunting, said Brian Solan, executive director of the Montana Wild Sheep Foundation. While the population is not at 125 in the Greenhorns, the herd has persisted without a die off and includes a number of older rams.
“Eliminating one older age class animal won’t have an effect on the population,” he said. “It’s also a great opportunity to raise awareness about that herd.
“We understand and support the 125 as a minimum to strive for; however, there are just certain aspects of Montana’s disease profile that make the idea of interconnectivity not so great. It’s a major challenge.”
Solan cited a lawsuit brought by the Gallatin group over the grazing of domestic sheep in the Gravelly Range. The lawsuit challenged a memorandum of understanding between a producer and wildlife managers who agreed to a wild sheep introduction with stipulations to keep domestics separate. The lawsuit has “paralyzed” efforts to transplant sheep elsewhere, he believes.
“Sheep spend much of the year up in public land in the rocks, but it’s critical that they have winter ground and that means private landowners coming on board,” he said. “The bottom line is we believe in approaching this from all angles, working with agriculture to figure out these disease issues.”