ST. GEORGE — The Bureau of Land Management recently reported that, for the third consecutive year, populations of wild horses and burros inhabiting the semi-arid plains, deserts, prairies, grasslands and badlands of the American West are experiencing a decline.
The most recent data from BLM indicates that as of March 1, there are an estimated 73,520 federally protected wild horses and burros on BLM-managed lands. This figure represents a decrease of 9,363 animals compared to the 2023 estimate.
Because of the inherent uncertainties in aerial and statistical analyses – one of the most common practices to judge wild horse populations – the estimates then range between 63,432 and 85,249 animals on federal land.
Although the precise reasons for the decline are not completely known, it is likely due to a combination of factors, said Scott Fluer, BLM deputy division chief for on-range operations for the National Wild Horse and Burro Program.
Fluer said the decline could be a result of manmade interventions such as the bureau’s fertility control vaccination program, as well as environmental climate changes from drought and harsh winters that kill many grazing animals. The natural conclusion, Fluer said, is that the numbers will reflect a decline.
Of particular significance, adding to the decline in the wild horse population is the bureau’s strategy of rounding up and removing animals from the open range.
Between 2020 and 2023, approximately 50,000 wild horses and burros were removed from public lands, compared to about 27,000 animals removed in the prior four years, 2016-2019.
“It’s a pretty aggressive gather schedule,” Fluer said. “In addition to that we continue to maintain our fertility control vaccination program and treatments on horses.”
Measures to control population growth encompass the deployment of fertility control vaccines to decelerate herd expansion. Between 2020 and 2023, approximately 4,237 treatments were administered, in contrast to the 2,606 treatments carried out from 2016 to 2019, as reported by the BLM.
The BLM plans to continue efforts to bring wild horse and burro populations back to a healthy level. The agency recently released its plan to gather and remove approximately 20,000 wild horses and burros and treat 1,400 horses with fertility control in fiscal year 2024, with the added goal of placing 10,000 animals into private care through adoptions and sales.
Based on population projections, approximately 20,000 animals should be removed annually, BLM literature suggests, and the use of fertility control should be maximized where it can be effective, to continue the downward trend.
“The bottom line is, we really want healthy horses on healthy rangeland,” Fluer said. “In order to achieve this is to have everything in balance to where we provide enough forage not only for horses but other wildlife and uses as well.”
It is important to note, as Fluer added, that forage on public lands usually grows annually from mid-April to June. This growth must be sufficient enough to support the plant species and animals that rely on it for survival.
“We’ve had multiple years of drought where plants were fairly stressed,” Fluer said. “In the summer of 2022, it was pretty severe. Then you add in a severe winter (2022-2023) with really deep snow conditions in the Intermountain West where some places exceeded 200% snowpack.”
Wildlife experts agree that wild horses and burros experience a higher rate of death during periods of weather extremes.
Laura Leigh, founder and president of Wild Horse Education, said she believes other reasons contribute to the decline.
“Most of the time what BLM says … is always a ridiculously simple explanation that counters their assumptions and uncertainties,” Leigh said. “What BLM consistently does is to carve up the wild horse habitat left and right. Access to water is being cut off. Normal seasonal migratory routes are being cut off. So … of course, population numbers are going to decline. In fact, BLM has removed 15,000 to 21,000 horses a year for the past five years; of course, populations are down.”
History of population growth
Over the decade leading up to 2020, wild horse and burro populations experienced substantial growth, rising from approximately 28,500 in 2007 to 95,000 in 2020, according to BLM data.
Leigh notes that BLM began to change the way they count horses and burros on the range using computer modeling tools and attributes much of the asserted explosive growth rates to “methodology, not actuality.” BLM states chronic overpopulation can degrade ecosystems, potentially causing starvation and dehydration for the horses and burros and adversely impacting other wildlife.
Suzanne Roy, executive director of the American Wild Horse Campaign, said it’s been “very frustrating” trying to change the way BLM thinks of and manages wild horse populations.
“The definition of insanity is to do the same thing over and over again, and they continued the roundups with unbelievable consequences to taxpayers,” she said. “Now, that approach has led us to this point where we have 64,000 horses and burros in holding facilities and plans to bring 20,000 more in this year.”
Roy takes pause with the range of wild horse decline as reported by the bureau.
“If it’s closer to the high end, that means the roundups didn’t have an impact, and if it’s closer to the low end, that means there’s 63,000 horses left in the wild, with more horses in holding facilities than on the range,” she said.
As of Aug. 21, 2021, Utah held approximately 1,910 animals – 1,799 horses and 111 burros – in its corrals with contracted off-range pastures.
While recent estimates suggest that 2023 witnessed the most significant one-year reduction in overpopulation since 1985, the current herds have the potential to nearly triple in size every four years. Consequently, the bureau has set what is known as Appropriate Management Levels to quantify the balance between population estimates and the land’s carrying capacity.
Some wild horse advocates question BLM’s methodology for determining these management levels.
“The AMLs (Appropriate Management Levels) the bureau is operating under are figures set in the (late) 1980s through politics,” Leigh said. “What scientists? BLM has never provided an equation on what the land can sustain. Instead, they’ve been affirming political AMLs by simply retyping (arbitrary) numbers from year to year.”
Fluer does not dispute the lineage of Appropriate Management Levels protocols.
“These were established at the field office level, state-by-state, and this was based on forage production, authorized or permitted use from livestock, as well as taking into account wildlife (impacts),” Fluer said. “Some of the AML levels may have changed a little, but not very much.”
The bureau manages 245 million acres of public lands – the most of any federal bureau – primarily in 12 Western states, which includes 28 national monuments, 23 national conservation areas and 260 wilderness areas.
In Utah, BLM oversees 19 wild horse and burro herd management areas on nearly 2.4 million acres. The combined Appropriate Management Levels set for all management areas in Utah is 1,956 animals.
BLM points to the success it’s had at the Reveille Herd Management Area located 50 miles east of Tonopah, Nevada.
The Reveille management area spans more than 105,000 acres of public and private lands with an Appropriate Management Level set at 82-138 wild horses. The latest census flight over Reveille carried out in February 2023, recorded roughly 164 adult wild horses, not accounting for that year’s foals, both within and just outside the management area. This number was almost 119% above the upper limit of the designated management level.
Through gathering and fertility control measures, Reveille population numbers are now considered at Appropriate Management Levels.
The Reveille management area encompasses an area 17 miles wide and 10 miles long. The area receives 5 inches of annual precipitation in the valley bottoms. The mountaintops can receive as much as 16 inches, but the average is 4-8 inches.
Summers are typically hot and arid, with temperatures often soaring into the 90s or beyond. Winters are frigid, with temperatures frequently falling below freezing and sometimes dipping below zero degrees. The herd management area experiences snowfall in winter, accumulating from a few inches to almost a foot, varying with the winter’s harshness and the area’s altitude.
The ideal Appropriate Management Levels at Reveille is between 82 and 138 horses, a figure the BLM established in 2001.
Reveille was among the first to be part of a new BLM initiative aimed at expanding the use of fertility control vaccines to slow population growth and protect wild herds from overpopulation.
The primary focus of “catch-treat-hold-release” operations is to gather wild horses, treat them with a fertility control vaccine, hold them for a determined amount of time (approximately 30 days), provide a booster treatment and then release them back to the range.
As part of the Reveille operation in August 2023, 29 mares were treated and released.
“Catch-treat-hold-release gathers give the BLM the opportunity to conduct a sustained and strategic fertility control program in places where we didn’t think we could before,” Fluer said.
The bureau has previously implemented fertility control measures during standard gathering operations. These operations mainly aimed to curb overpopulation by relocating surplus animals into private care.
Conversely, catch-treat-hold-release gathers are concentrated on herds that are at or close to their ideal Appropriate Management Levels. According to the BLM, this approach enhances the efficacy of the fertility control program, as it allows for a larger segment of the herd to be treated and subsequently released.
In addition to catch-treat-hold-release, certain wild horses are administered fertility control vaccines through ground darting.
As of August 2023, the bureau endorses darting programs for over a dozen herds throughout the West, often in collaboration with volunteers and partners; however, these programs are not suitable for all herds. Ground darting is generally more effective in regions where the animals are regularly accessible and in herds that are more amenable to human interaction.
Overpopulation management
According to a 2021 BLM report to Congress, the first recorded count of wild horse population numbers was conducted in 1974. At that time, the count was nearly 60,000 animals. Because of limited technology and visual one-time assessments, the animal numbers could have been undercounted by as much as 50%.
While drought and climate change have been linked to extreme conditions that affect nearly all western species, wild horses and burros’ primary threats come from human activities and uncontrolled breeding.
Despite her objections to BLM practices to control wild horses and burro populations, Mary Cioffi, president of Pine Nuts Wild Horse Advocates, is bullish about the future.
“I’m always optimistic, but I’d actually like to see the handling of the Wild Horse and Burro Program taken away from the BLM,” Cioffi said. “We need to have someone else in charge. Although the BLM is mandated to manage wild horses, they seem to be leaning more toward (actions) influenced by the livestock industry rather than actually preserving wild horses.”
Since March 2023, the BLM has removed 11,784 animals and offered them for adoption – placing 7,887 animals into private care sales and transfers to other federal agencies.
When asked why people should care about the plight of wild horses and burros, the answer is simple, Roy said.
“Wild horses are protected under the law as symbols of the spirit of the West,” she added. “They are incredible, iconic animals … that are an important part of the American culture and history. In a world that so much of the wild has been lost, there’s still places in the West that wild horses run free — and that matters.”
New research
Despite years of disputes and legal actions taken by wild horse advocacy groups against the bureau, effectively managing herd populations may ultimately rely on applied scientific research.
Currently, the bureau administers the Porcine Zona Pellucida vaccine and GonaCon as the preferred birth control methods in wild horse populations.
However, these vaccines have come under fire for their alleged lack of reliability.
Studies by the Science and Conservation Center indicate that while the BLM has implemented PZP vaccination for wild mares across the West, achieving a 90% effectiveness rate requires administering the vaccine to a substantial number of mares.
In its endeavor to control the population growth of wild horses on public rangeland, the bureau has been backing the development and examination of different contraceptive methods since 1978. Research funded by the BLM over time has revealed that certain methods, like hormone implants or chemical vasectomies, are either ineffective or not feasible.
“BLM constantly tries to shift the conversation to a narrative of population growth suppression. As long as they are addressing that, they believe they are managing the wild horses — this is absurd. There shouldn’t ever be a one-size-fits-all approach to fertility control,” Leigh said. “I’m not an idiot. I know range resources are limited, but we also have to have a conversation about how to preserve critical habitat.”
In 2023, the bureau approved two studies to evaluate new fertility control vaccines aimed at mitigating the overpopulation of wild horses on public lands by reducing their annual growth rates. These research initiatives, conducted at a corral facility in Carson City, Nevada, contribute to the BLM’s comprehensive strategy to sustain healthy wild horse populations on thriving public lands.
One study, undertaken by researchers from Cornell University College of Veterinary Medicine and Northwest Wildlife Conservation Research, is examining if a version of PZP called SpayVac is more durable when administered in the neck muscle compared to the flank.
Another study, conducted by the U.S. Department of Agriculture Animal and Plant Health Inspection Service’s National Wildlife Research Center, is investigating which Oocyte Growth Factor vaccine formulations induce prolonged contraception with just a single dose.
In a separate suit of studies, on Nov. 1, 2023, the bureau released a new Request for Proposals and Notice of Funding Opportunity to solicit research proposals that address any of the priority research topics that were identified in the BLM Wild Horse and Burro Program 2021 Strategic Research Plan.
Porcine Zona Pellucida vaccines and vaccines used against gonadotropin-releasing hormones, such as GonaCon, have been in use since the 1990s; however, questions regarding BLM’s narrative about GonaCon – in particular – have wild horse advocates questioning the bureau’s thoroughness in its continuing research on this vaccine.
“BLM did not do the research on GonaCon’s one and two-dose efficacy,” Leigh said. “GonaCon has been used in the veterinary community for a very long time to treat ovarian disease in domestic horses with the efficacy for the two-dose vaccine known to be four-10 years.”
In recent years, the BLM has accelerated the application of longer-lasting hormonal vaccines.
Research suggests that one dose of the GonaCon vaccine is “marginally” effective for one to two years. However, BLM uses the two-dose formula that has reportedly shown that if a mare receives the booster dose, she can be infertile for a minimum of four years and as long as 10.
Two formulations of the PZP vaccine are currently in use: Zonastat-H and PZP-22. Both have an efficacy of one to two years with a booster needed for PZP-22 to increase its effectiveness to three years.
“In their lingo, they call it a one-and-done shot, that’s what they want – a one-and-done shot, but it’s hard to evaluate exactly what is available because there’s no information,” Roy said. “These methods, if there is a viable one-and-done method, could be one-and-done to the future of the herds.”
Despite the difficulties in managing wild horse populations, many Americans hold these majestic creatures in high esteem as living symbols of the country’s pioneering past. The sentiments of the American public toward wild horses vary widely, mirroring the multifaceted nature of the debates surrounding wildlife management, conservation and cultural significance.
Regardless of the challenges, wild horses remain a significant reminder of the enduring spirit of the American West.
“The sight of a herd of wild horses galloping across the landscape, their hooves thundering against the ground, is a spectacle of nature that leaves one breathless. The dust they kick up, the sound of their whinnies and snorts, the sheer energy they exude combine to create a scene of raw, untamed beauty,” said Jonathon Poe, wild horse advocate, during a recent open group discussion on Facebook.
“The majesty of wild horses lies not just in their physical beauty and power but also in their spirit,” Poe added. “They symbolize freedom and resilience that reminds us of the wild, untamed parts of the world and of our own wild, untamed spirits. Wild horses are a testament to the majesty of the natural world and a symbol of the wild beauty that still exists, if we only took the time to look.”
Copyright St. George News, SaintGeorgeUtah.com LLC, 2024, all rights reserved.