Disease, domestic sheep proximity, habitat degradation, human encroachment, water construction, predation—all part of the tangled web of problems for bighorns. But there are still other pressing problems for these animals that may have deeper consequences.
A big stumbling block biologists are facing is connectivity. Sky Islands and basin/range topography are comprised of isolated islands of habitat. Minimal population size for healthy genetic diversity seems to be around 200 animals to ward off most stressors. Historically, desert bighorns existed as metapopulations, large areas of basin/range where bighorns could roam and connect freely. A bighorn population wasn’t just one mountain top, but a wide swath of desert and mountains containing sub-populations inside of metapopulations. Harley Shaw commented to me that in looking at the history of desert bighorns in the Southwest, his view was that historically mountain ranges with these small populations were constantly winking out. Roaming instincts would push a few bighorns across desert floors to repopulate new ranges. Today that’s a near impossibility.
The entire state of Nevada alone was once considered one large population of bighorn sheep. “Moisture is so spotty, and we have so many rain shadows,” Mike Cox from Nevada Department of Wildlife relates, “that bighorns were very nomadic. They would chase green-up.”
I asked Cox about connectivity today . “It’s pretty sad, especially in Clark County which is the county of Las Vegas. We have islands, these sky islands of bighorn sheep that can’t go anywhere. They can’t roam. They can’t go on forays or they’ll get killed on 6 or 8 lane highways.”
Along with roads and barriers, there is the issue of a roaming bighorns coming into contact with domestic livestock and disease. Without a viable solution, many wildlife agencies resort to periodic infusions of additional bighorns on a mountain. With new knowledge of disease strains, even that has its limitations. Amber Munig with AZGF told me the agency was looking at boosting a bighorn population southwest of the Colorado River. They tested both herds and although both have titers for Mycoplasma ovipneumoniae, the strains were different so they cancelled the translocation.
“Our translocation program is slower now because we don’t have as many areas to put them into and we’re very cautious about moving pathogens from one population to another,” Munig says. “We’re mostly supplementing existing populations at this point in time to ensure the genetics is still there and that becomes a concern when you have fragmentation, especially with roads that don’t allow them to cross between mountain ranges.”
Mike Cox is looking towards another answer. Some of the new research points to chronic asymptomatic disease shedders as the reason why a herd just cannot recover. The newest push is to find these shedders and kill them, called “test and remove.” Experiments in Oregon’s Hells Canyon by researcher Francis Cassirer shows promising results with a natural fade-out of the disease over time when carriers were removed in connected populations. But, as Cox points out to me again, “just because one bighorn gets one Mycoplasma strain doesn’t mean the next strain that comes along won’t be worse. There is no immunity that’s generated from one to the other.”
Jessica Moreno with the Coalition for Sonoran Desert Protection looks to wildlife linkages as a viable solution for healthy wildlife. Focusing mainly on Pima County around the Greater Tucson area, the Coalition partnered with Arizona Department of Transportation and others to plan a wildlife crossing. The crossing, one under and another over State Route 77, were installed simultaneous with the final bighorn translocation into the Catalinas in 2016. This first of several planned crossings connects the Catalinas to the Tortolita mountains. The next crossing is planned for Interstate 10, a more challenging endeavor, that would continue the wildlife passage from the Tortolitas to the Tucsons, the Silverbells, and through Saguaro National Park West into open desert country and Tohono O’odham Nation Reservation.
Moreno’s viewpoint is that bighorns face a tangled web of stressors, and many we might not even understand or recognize as stressors. But if we look at the bigger picture, giving the bighorns roam to connect, even if one population crashes, more bighorn sheep will come in to boost the population.
“By taking that landscape approach, you allow the animals the freedom to respond to stressors on their own, leaving that option available so they can respond to fire, disease or climate change. Their populations can crash but then rebound the way they need to. I like that about the work I’m doing to establish wildlife corridors and build wildlife crossings as it reaches across different species and gives a little bit more resilience to those populations that are dealing with different pressures.”
So far, with trail cameras placed in the area, State Route 77 crossing hasn’t produced any bighorn sheep using it over the last four years. But it still can be considered successful, with over 5,000 mule deer using it, along with javelinas, bobcats, coyotes, and lots of smaller species. But crossings elsewhere have been successful for bighorns. Wildlife crossings installed between Kingman and the Nevada state line on U.S. 93 between 2007 and 2011 documented use in the first four years by over 6.000 bighorns. Given the complexity of disease issues, it’s hard to know if these kinds of connections might solve the fresh genetic flow yet doom a population to new strains of disease.
The biggest unknown of all is our rapidly changing climate. Connective corridors undoubtedly help facilitate movement, allowing wildlife to adjust to habitat changes and water availability as their environment heats up. The totality of all the issues affecting bighorn sheep in particular is complicated and nuanced. Connective corridors might solve one piece of their Gordian knot but certainly not all.
I grab my snowshoes, prepare a few snacks, and head up to a high mesa locals call Little Bald Ridge. In deep snow it’s difficult to follow the spines of the lower ravines that lead to the mountain top and the animal trail that hugs the hillside higher up would be obscured. But we’ve had little snow this winter and today with a clear sky, a light wind, and temperatures in the teens, it should only take an hour to climb to the wide butte.
I’m hoping to see our little band of Rocky Mountain Bighorn Sheep. They like the wind-swept meadows and craggy overlooks. The elk covet the area too, though the two species never group up. Wolves might be there, but their interest is in the scent of the elk, not the bighorns.
The final ascent leaves me a bit winded. The trees have disappeared. I always have to remember to watch for a large sinkhole beside the animal trail, which the trail swings directly alongside. The elk have trodden down the snow by its edges, but the hole is steep and deep and makes me nervous. I climb the last few hundred yards to the meadow expanse. The ground is cropped clean from the large elk herds who take advantage of this high windy spot that sweeps the snow clear. Even the sagebrush is just bare stems. As I clear the rise, I spot the bighorns. A small herd of ewes and lambs clasp the rocky cliff edges along the eastern rim. The meadows stretch to the west in a large expanse. Picking up my binoculars, I see a mixed age group of rams grazing in a hollow below.
I’ve been here before in winter without seeing bighorns or elk. The wind is usually in a howl, which highlights those moments of deep terrestrial loneliness. Without the bighorns, this top-of-the-world is not right. It’s definitely special to see the bighorns here today. Even so, these small groupings evoke both elation and sadness. I know that on these same ridges just a few hundred years ago, the native peoples who lived in these mountains watched herds of hundreds, perhaps thousands, of bighorns. These ones today are the hanger-oners, the bighorn sheep that survived the onslaught of white men and their livestock diseases. They are the toughest, yet they eye me with sweet docility, unafraid of my presence. I sit down a few hundred yards away and enjoy. Soon they pay me no mind, and go about their browsing business.
Bighorn sheep appear tough because of the rugged places they live, yet in reality they are soft creatures, whether we are speaking of their animal nature or their constitution. Just being with them I feel softer. I’d like my grandchildren to be able to experience their soft-tough nature. The fact that their presence on this planet coincides with ours implies we must care about their plight, not let it extinguish. That forces us to answer difficult ethical and moral questions. First, there is the money that supports these herculean efforts to help bighorns. Where does it come from? We’re talking about millions of dollars. All the western Fish and Game Agency bighorn sheep programs obtain one-quarter of their revenues from bighorn hunting licenses sold to the general public. The other three-quarters comes from Governor’s auctions and raffles. Kevin Hurley of the Wild Sheep Foundation gives me an example.
“In South Dakota, by statute, there are only two bighorn sheep licenses and they are resident only. That generates $550 a year in revenue. The first year they had [a governor’s tag], it sold for $102,000, and 100% of it went back to South Dakota Game, Fish and Parks. So for $102,000 think what can you do for bighorn sheep versus $550.”
Very few bighorn hunting tags are sold per state every year. The situation with bighorns is just too precarious. What supports bighorn sheep programs are these tags that are up for bid at auctions, bought by the super wealthy. For instance, Rick Smith, a retired telecommunications executive from Dallas, was the highest bidder in New Mexico’s auction and won seven tags over eight consecutive years to hunt bighorn sheep. He spent over $1 million dollars on those tags, 90% of which goes directly to New Mexico Game and Fish’s bighorn sheep enhancement program.
If we value bighorn sheep then there needs to be a way to fund programs that support bighorns other than through hunts and super tags. There is something obscene in the sole financial support to save bighorns throughout the West—native wildlife which are in the public trust—relying on a sliver of mega-rich trophy hunters. Additionally, being dependent exclusively on hunters for bighorn dollars creates a vicious cycle that pressures agencies to put more bighorns on every mountain so as to increase revenue. It also fuels extreme predator management programs like in New Mexico, where the culling of lions never ends despite bighorn herds that are thriving.
Funding is only one aspect. I think we have to be honest—the intensity of life-support programs that especially desert bighorn sheep need may soon be beyond justification. We need to ask ourselves the hard questions. Can we continue to transport water, not only because of the price tag, but as water itself becomes more precious in a thirsty Southwest, will the program even be sustainable. With the extreme drought conditions of 2020, Arizona hauled close to one million gallons of water, some even by helicopter.
Mycoplasma ovipneumoniae is here for the long run. Researchers are still puzzled how to control it and how to deal with emerging new strains. If we support separation of bighorns from domestic sheep and goats, are we willing to boycott wool from Western growers? Or to contribute cash to buy out wool growers and their public lands grazing allotments? While Bighorn Sheep NGO’s have already been actively raising dollars to help retire grazing allotments, isn’t this the responsibility of all Americans? Again, wildlife are in the public trust, therefor all of our responsibility.
It’s obviously absurd and expensive to keep plopping new bighorn sheep recruits into mountain ranges to enhance their gene flow. Should we instead adopt the “test and remove” program, where shedders are identified and culled? Do we give this kind of program a cut-off limit?
There is a point sometime in the future where we’ll have to cut bighorns loose. Yet we do have an obligation to the bighorns to do our best for them, to right so many of the wrongs they’ve suffered from our misdeeds. In my mind, perhaps our best is displayed in places like the Desert National Wildlife Refuge in Nevada or San Andres National Wildlife Refuge—immense tracts of mountain ranges surrounded by even larger tracts of wild areas completely off-limits to the public and livestock. Allow the bighorn populations to fluctuate naturally.
Instead of trying to fill every historically occupied mountain with bighorn sheep, we should consider a sub-population model, where suitable habitat can provide the bighorn sheep natural connective corridors to other nearby ranges. Land might need to be purchased to enlarge the protected area and grazing allotments retired. Initial habitat restoration would be completed, then we’d just let bighorns be bighorns, and lions be lions. This would be asking a lot of the general public; we all need to step up, not just hunters and the super-rich who can buy tags. An egalitarian effort is needed; an extreme push, perhaps a sprint rather than a marathon. For the bighorns sake, it’s time to decide if we are all willing to rise up to the task this implies—guardians of the ancient way of life of the bighorn sheep. At the very least, we owe it to the bighorns to take a hard look at ourselves and what we are willing to do.