The wild horses on Assateague were protected by the National Park Service in the 1970s, but with no plan in place to limit population. By the late 1980s, the narrow island had 175 horses—more than the Park Service thought the sandy spit could handle. Kirkpatrick got a call from a ranger on the island, asking whether he could do anything to control the horse population.
“I didn’t even know there were horses out there,” Kirkpatrick said, recalling the conversation, but he said he would give it a try. An isolated island was the perfect test for PZP. In February 1988, he and Turner arrived on the island with a gun and a box of darts. The plan was to bring the population of 175 horses gradually down over several years to 100 and hold it there through annual darting. Each horse would get shots for three seasons, then be allowed to have a foal. That would allow the genetics to be passed down, while limiting growth of the herd.
Kirkpatrick and other researchers began sloshing through the marshes and crashing through the brush. At first it was easy. The horses were so used to tourists that the researchers could walk within ten yards, load a dart, and fire. But as the team started going back spring after spring, the horses got smarter. They started to recognize the men and remember the sting of his dart. They kept a wider and wider distance. The darters learned too, though. They began to feign a lack of interest. Kirkpatrick pretended to be a tourist clamming or bird-watching. He ambled toward each mare in a series of tangential sashays, until he was close enough to hit his mark. The team learned to recognize each horse, keeping a folder with the markings and age of each, and the date when they were darted. The herd stopped growing and gradually started to shrink. The data showed the drug was about 90 percent effective, and, just as important, a small group of people, or even one individual, could deliver it by dart. The cost was far lower than any other alternative, including roundups. The project continues to this day.
“It was the shot heard around the world,” Kirkpatrick told the small class. “The first time anyone had controlled fertility in a wild population.”
Kirkpatrick and his colleagues published their findings in the Wildlife Society Bulletin in 1990. Soon, he was getting calls from around the world from people who wanted to use PZP on elephants, elk, zebras, tapirs, bison, bongos, giraffes, and hippos, even bats. The need for controlling wild populations in the field stretched well beyond horses. He traveled the globe doing tests. “With cats it doesn’t work,” said Kirkpatrick “but with bats it works. And anything with a hoof, it seems to work.”
Kirkpatrick founded The Science and Conservation Center in a back lot of the zoo in Billings to produce PZP from discarded pig ovaries and teach people how to use it. He invited wildlife managers from around the world to take his classes. Today, PZP is used in zoos, African game parks, suburban deer herds, and a bison herd on California’s Catalina Island.
For years, there was pushback from wild horse advocates who viewed PZP as potentially harmful to the wild herds. Research shows that PZP does have some impacts, but, on balance, negative effects seem negligible, and PZP may actually benefit herds. Kirkpatrick and other independent academic researchers found that mares that did not give birth every year because of PZP were in better condition and lived longer. They also found that mares treated with the vaccine generally spent their days the same way as untreated mares, though, as might be expected with no one pregnant, there was more time spent on what reports call “reproductive behavior.”
Scientists also looked at whether the drug would destabilize bands as mares looking to get pregnant went to find new stallions, or stallions might be becoming more stressed and aggressive. Results have been mixed, with some researchers reporting more instability and others not. But even in studies where researchers did find some disruption in social structure among the herds, mares were healthier and lived longer.
Of course, it is wrong to claim that there are no effects from PZP. Whenever you interrupt a population in a way as profound as limiting reproduction, there will be broad consequences. But there are already consequences now imposed by years of helicopter roundups. Which method is less disruptive? Kirkpatrick bet on PZP. And so did a growing number of wild horse advocates.
Despite its widespread success, however, PZP has largely missed its intended target—the mustangs of Wild Horse Country. It’s not that wild horse tests weren’t promising. Turner and Liu gave PZP to several dozen mares captured by a BLM helicopter roundup in Nevada in 1992. Only five percent of the mares got pregnant in the next twelve months, compared to 50 percent of untreated mares.
The BLM knew for decades that rounding up horses and putting them in storage was a losing strategy. Its own advisory committees warned against storing horses and urged development of alternatives. In 1980 and again in 1985, a National Research Council study recommended using fertility control. It produced reports that showed treating a horse with PZP costs about $110 per year, and rounding up a horse and putting it in storage for the rest of its life costs about $50,000. In 2001, when the BLM persuaded Congress to double its budget so it could round up more horses to reach the elusive goal of twenty-seven thousand horses on the range, it did so in part by saying it planned to start aggressive use of PZP. BLM directors have repeatedly said they are changing their old ways and moving to PZP. But they never have—at least in any meaningful way.
The number of horses darted has always been too small to make a real difference. A herd might be darted one year, but not the next. Sometimes supplies of PZP weren’t refrigerated, and became useless by the time they were injected. And the expertise to manage a herd over time was hard to maintain as federal employees came and went.
After years of having little luck with the BLM, a partial solution came knocking at Kirkpatrick’s door. Certain herds were watched by admirers like TJ Holmes who were determined to end helicopter roundups. Those advocates had the will to push local managers and the knowledge to recognize individual horses as they were darted, so they could be recorded. A few of them came to Kirkpatrick asking for help. When their efforts proved successful, more came.
At the Little Book Cliffs Wild Horse Range in western Colorado in 2002, the US Geological Survey Biological Resources Division funded a small study of PZP. It started with injecting mares that had been rounded up by helicopter. Then two longtime wild horse watchers from nearby Grand Junction stepped forward and offered to start treating the mares with a dart gun. Reproduction rates in treated horses were soon cut by 75 percent. Volunteers have been darting the herd ever since. “We knew that area better than the BLM did,” said Marty Felix, a retired elementary teacher who taught herself to shoot a dart gun, told me. “So we taught ourselves how to do it, and I think we’ve done pretty well.”
Also in 2002, volunteers in the Pryor Mountains, led by a local man named Matt Dillon, began darting horses—though the program has attracted some controversy and it has not happened every year. From there, the use of PZP spread as people began to see results. In 2008, the Humane Society of the United States funded a test of a new slow-release version of PZP, called PZP-22, which would last two years. They darted horses in the Sand Wash Basin in Colorado—an effort volunteers continued even after the study concluded in 2012.
In 2011, a small group of citizens calling themselves Friends of a Legacy, or FOAL, who advocate for horses in the McCullough Peaks Herd Management Area of Wyoming, started pushing for PZP. They convinced their local BLM office that PZP would be cheaper than helicopter roundups, which, even in its small herd of about 140 horses, cost about $120,000 per roundup. Two women from the group trained with Kirkpatrick and started a program.
The same year, TJ Holmes posted this on her blog: “Read carefully: The Little Book Cliffs roundup this fall has been canceled. Canceled. Now ask ‘why?’—and why am I doing a victory dance?” The reason, she said, was PZP. She was so impressed that she immediately began planning a similar program for the horses in Spring Creek Basin.
Volunteer groups inspired by the success of areas like Little Book Clif
fs have continued to adopt PZP.
With the holding system near bursting, the Department of the Interior requested a review of its management program from the National Academy of Sciences to find an alternative that would help solve the problem. In 2013, the group published a 383-page report called Using Science to Improve the BLM Wild Horse and Burro Program: A Way Forward.
Its panel of experts, which studied the problem for two years, began the report with a quote from Lao-tzu: “A journey of a thousand miles begins with a single step.” The report went on to say:
It is clear that the status quo of continually removing free-ranging horses and then maintaining them in long-term holding facilities, with no foreseeable end in sight, is both economically unsustainable and discordant with public expectations. It is equally evident that the consequences of simply letting horse populations, which increase at a mean annual rate approaching 20 percent, expand to the level of “self-limitation”—bringing suffering and death due to disease, dehydration, and starvation accompanied by degradation of the land—are also unacceptable.
The report recommended the BLM start a fertility-control program immediately. (It’s worth noting that the panel was not allowed to explore euthanizing horses.) Nearly all of the major wild horse advocacy groups backed the proposal, calling PZP “a cost-effective alternative to roundups and removals of wild horses from the range.”
The BLM issued a statement, saying it “welcomed” the recommendations and planned to act. “The report will help the BLM build on the reforms that the agency has taken over the past several years to improve program effectiveness, such as the stepped-up use of fertility control,” it said.
Then . . . it did nothing.
Grassroots groups kept expanding their efforts. In 2014, volunteers with Wild Love Preserve began darting horses in the Challis Herd Management Area in Idaho. In 2015, volunteers started darting horses in the Onaqui Herd Management Area in Utah. In 2016, the American Wild Horse Preservation Campaign and the Humane Society of the United States announced a five-year program focused on Nevada’s Virginia Mountains—the same region where Velma Johnston got her start.
But the BLM actually decreased its use of PZP. In 2012, the BLM said it would inject a record two thousand mares. Instead, it treated only about 1,015. In 2013, it planned to treat far fewer: about nine hundred. But it only treated about five hundred. In 2014, it treated about 380. In 2015, it treated about four hundred. Just to hold population growth steady, the program would need to treat about thirteen thousand mares a year.
Why did the BLM do so little? Largely because it was stuck in a cycle of roundups. By 2013, when the report was released, there were forty-seven thousand horses in the holding system, eating up most of the budget that would be needed to scale up a big fertility-control program. Making problems worse, the BLM views the use of dart guns as impossible in large herd areas where there is little cover. To apply PZP, it says, it must still round up horses with helicopters and inject them by hand. That cuts the savings of using PZP.
There were also potential legal challenges in herd areas where horses were already over the prescribed population. In 2015, ranchers took the BLM to court for planning to release horses it had just treated with PZP. Try telling a rancher in a valley where the horse population is six hundred horses over the limit that you are not going to round up horses and instead are going to start a darting program that could take a decade. A rancher like Joe Fallini might say, “I’ll see you in court.”
When I met with Dean Bolstad, the director of the BLM’s Wild Horse and Burro Program, in 2016, he said he wanted to use more PZP or other fertility-control drugs—a lot more. But they were still impractical. Darting mares every year was too much work. They needed a drug that lasted five years, not one. Kirkpatrick’s longtime colleague, John Turner, was trying to make a longer-lasting version of PZP that would meet the need, but it had not yet been proven effective enough to fit BLM goals.
That could soon change. In recent years John Turner has been working on making a long-lasting PZP vaccine, and found that darting horses with PZP-22, then regular PZP a few years later, offered a longer period of infertility. The combination produced about four years of contraception in a six-year period.
More than anything, though, the BLM was getting pressure from ranchers.
“We can’t leave horses on the land, they are overpopulated,” Bolstad told me. “We have to gather.”
He also didn’t think shooting horses with darts was practical in most of Wild Horse Country. “You might be able to sneak up on a horse in Colorado,” he said, “but try doing it in Nevada. You can’t get within 200 yards.”
I actually have my doubts about that, especially since horses have to come to a few places in the desert to drink. It would be possible to set up blinds near springs and dart the horses as they came to drink.
Sitting in his office after teaching the class how to shoot a dart gun, Kirkpatrick looked back at the twenty-five years of inaction by the BLM that followed his successful application of PZP at Assateague. He shook his head. “The BLM is still staffed by cowboys,” he said. “And cowboys have a certain way of doing things. They want to round things up. Practically, PZP was a success. Politically, it has been a total failure.”
In December 2015, Jay Kirkpatrick died of cancer. He was seventy-five. The last time I met him, a few years before his death, he was pessimistic about the future of wild horses and wild animals in general. I asked him for predictions about the years ahead. Human populations would continue to grow, he said. Resources would become increasingly scarce. Wide-open spaces for large animals would disappear.
“I just don’t see how the horse can win in all that,” he said. But then he grinned and added, “But we can try.”
That seems to be the strategy of the grassroots groups on the ground now. They are scraping together funds and training volunteers to fire darts. They have had successes persuading the BLM to give them a hand in management. But increasingly, they are facing an unexpected obstacle: other wild horse advocates.
A number of people oppose management of wild horses in almost all forms, and refuse to support PZP. A Connecticut-based group called Friends of Animals has become the leader of the opposition, teaming up with a small but vocal organization out of Berkeley called Protect Mustangs. Friends of Animals had not been involved in wild horse advocacy before, but in 2015 it went all in.
That year it sued the BLM over a proposal to use PZP in Nevada’s Pine Nut Mountains Herd Management Area. The project had the backing of all the major wild horse groups, and had volunteers lined up, but Friends of Animals successfully argued in court that the BLM had not done its planning paperwork properly. The BLM canceled plans to dart, and instead in 2016 asked the volunteers to dart the horses in the nearby Fish Springs area. Friends of Animals sued again. In court, its lawyer argued that allowing private citizens to dart mares with guns constituted “harassment,” which is forbidden by the 1971 law. It was also ready to argue that the behavior changes seen among mares darted with PZP violated the management guidelines of the law. Rather than fight a precedent-setting legal battle that could end all use of PZP, the bureau suspended the Fish Springs project. In the summer of 2016, Friends of Animals sued again, this time to revoke regulatory approval for PZP, which it calls a “restricted use pesticide,” ending all PZP projects in Fish Springs.
Friends of Animals also lambasted the BLM at public meetings. At a Wild Horse and Burro Program advisory board meeting in Nevada in 2016, the group’s “campaign director,” a willowy young vegetarian from Manhattan, stood up and laid into the agency. “We are disgusted with sitting in these meetings year after year and hearing this nonsense,” she said. “We will continue fighting legally to challenge roundups, to challenge [the] PZP Frankenstein monster show and we will continue and continue and continue to show up and we will not be silenced. . . . We are not here to beg or plead for the BLM to do the right thing, because we already know it is a hopelessly c
orrupt agency that acts as an extension of the meat industry.”
Men in the audience yelled for her to sit down. Someone yelled, “Cut off her mic!” An armed officer escorted her out as she yelled, “BLM lies! Horses die!”
For TJ Holmes, PZP was an attempt to avoid the type of controversy now being stoked by Friends of Animals. Protest is easy, she acknowledged, but finding policy that works is a lot harder. PZP is far from perfect, but right now, she said, it is the best option, and she sees tracking and darting horses in Disappointment Valley as an act of love and dedication, not harassment.
Holmes hoped to end the pointless protests and wasted money that roundups created so that the local BLM could focus on managing the land. It seemed to be working. Before she started darting in Spring Creek Basin in 2011, the local herd had thirteen surviving foals. The next year, they had nine foals. The next year, three foals. She hopes she never again sees a helicopter in the area.
The boundaries of the Spring Creek Herd Management Area are outlined with barbed wire and natural barriers. Forage is limited. Water is scarce. But if Holmes and a few other volunteers can keep the population stable, life will be a little easier for the herd.
“In the beginning, I said I’d never dart my horses. They know me, they trust me, I’m their friend,” she said. We stood watching a band of seven mustangs grazing a hundred meters away. “But it is the only way. These guys have so little here. If it is destroyed, they’re gone. People like to think we can just let them run wild. But I don’t think we live in that world anymore. I don’t think we have a choice.”
There is no doubt PZP works. And no doubt that small groups of people can use it effectively to manage wild horse herds. Or that doing so can save millions of dollars. But after learning about how it is used to control wild horses, I was left uninspired. Other longtime voices in the wild horse world that I talked to agreed. Almost everyone thought it was the best option, but no one really liked it. The vaccine may be practical, but it is not beautiful. It relies too much on human interference. The wild horse of myth must be independent. But the real wild horse is equal parts animal and myth, both flesh and legend. That has been the tension since the 1971 law was passed. How can you protect the myth but still manage the flesh? PZP takes care of the flesh, but in the process it contaminates our notion of what is wild and free. We love wild horses because they are not managed, not controlled, not tainted. We love them because the White Stallion can’t be caught. Take that away and the wild horse is just livestock.
Wild Horse Country Page 28