Fraudulent figures, sterilization and underpopulation

PM Burros Wild 2 © Carl Mrozek

To:  Heather van Blokland at KJZZ

Rio Salado College and Maricopa Community College, Arizona

I am emailing you directly because comments cannot be posted to your article.

First, let me commend you for correctly identifying PZP as a “sterilization drug.” The Bureau of Land Management (BoLM) and the Humane Society of the United States (HSUS) both like to refer to it as “birth control,” but PZP is actually a sterilant.  More on that later.  The reason for my email is to alert you that BoLM has given you false information regarding the wild horses and burros.

While a reporter or any member of the public should be able to secure accurate data from government agencies, BoLM’s data is fraudulent as concerns wild horses and burros.  BoLM is aggressively pursuing a disinformation campaign against the mustangs, concocting a crisis that does not exist, and using scare-tactics to secure increased funding for itself.  Let me now address certain points cited in your article.

Herd-growth rates:  Equids are slow-growth species when it comes to reproduction. The gestation period for horses lasts 11 months, and a mare produces just 1 foal.  The gestation period for burros lasts 12 to 14 months, and a jenny is less fertile than a mare.  While an independent study of BoLM’s records did confirm an almost 20% birth rate for wild-horse herds, and an almost 15% birth rate for wild-burro herds, the study also found that 50% of foals perish before their first birthday.  Thus, the effective increase in population from new foals is just 10% for wild horses and 7% for wild burros.  Adult mustangs also die.  They succumb to illness, injury, and predation at a rate of at least 5% a year. So, what is a normal herd-growth rate?  Around5% for wild horses and about 2% for wild burros, probably less in each case.  Thus, a herd could not double every four years — that’s just BoLM propaganda.

Fraudulent figures:  There is no overpopulation except on BoLM’s falsified spreadsheets.  Reviews of the agency’s population-estimates reveal biologically-impossible herd-growth rates.  For instance, in Arizona, BoLM reported that the Big Sandy herd grew from 250 burros to 754 burros in one year, a 202% increase.  In Nevada, BoLM would have us believe that the Lava Beds herd grew from 40 burros to 350 burros in one year, a 775% increase.  In Wyoming, BoLM declared that the Salt Wells Creek herd grew from 29 horses to 616 horses in 6 months (yes, months), a 2,024% increase.  The agency’s “data” is chock-full of such preposterous growth-estimates.  So, when you hear talk of how the wild horses are reproducing “exponentially,” that’s a sure sign that the numbers have been falsified.

Wild horses and burros are underpopulated:  Per the guidelines of BoLM’s own geneticist, 83% of the wild-horse herds and 90% of the wild-burro herds suffer from arbitrary management levels (AMLs) set below minimum-viable population (MVP).  Low AMLs enable BoLM to claim an “excess” in herds whose numbers, even if they were over AML, would still not reach MVP.  For instance, the AML for Arizona’s Black Mountain herd was set at 382 to 478 wild burros.  The Black Mountain Herd Management Area comprises 925,425 acres, or 1,446 square miles.  Thus, per the AML, BoLM implies that each burro needs 1,936 to 2,423 acres, or about 3 to 4 square miles per burro.  If BoLM projects there to be 2 burros per 3 square miles, the agency declares an “overpopulation” because there is “double the number” that the AML allows.  As you can see, being “over AML” is meaningless as well as misleading.  But the low AMLs, combined with falsified, biologically-impossible herd-growth estimates, give BoLM an excuse to scapegoat those few wild horses and burros for the range-damage done by the millions of livestock that overgraze the public lands.

Adoptions:  Have not declined — let alone “disappeared” — contrary to what BoLM led you to believe.  It’s just that BoLM used to count the thousands of sales-for-slaughter as “adoptions.”  Now that only true adoptions — “forever-family” placements — qualify, it just seems as if the number has declined.  However, wild horses are not homeless horses.  They have a home — where they belong — on the range.

HSUS:  Is the registrant of PZP / ZonaStat-H with the Environmental Protection Agency.  Thus, HSUS’ information is not impartial because the organization has its reputation to protect.  Further, HSUS has submitted a proposal for a multi-year project in which BoLM would pay for HSUS staff to experiment on Arizona’s burros via “opportunistic” darting with PZP.

Pesticide:  PZP is not just a sterilant but also a registered pesticide that was approved by the EPA for use on wild horses and burros “where they have become a nuisance.”   However, PZP was registered without the standard testing requirements.  There is currently a lawsuit challenging the legitimacy of the registration, especially in light of new studies that have disclosed PZP’s many adverse side-effects.

Sterilizing mustangs:  PZP is a potent weapon in BoLM’s arsenal — for its biological warfare against the wild horses.  But population control for wild horses is unnecessary because there is no overpopulation.  Why would we contracept herds whose population is inadequate for genetic viability?  Why would we contracept herds based on falsified figures?  Logically we wouldn’t and ethically we shouldn’t.  Further, if PZP were going to stop the roundups, it would have done so long ago for the famous Pryor Mountain herd, home to Cloud, the stallion who was the subject of a number of documentaries that aired on PBS.  The Pryor Mountain mares have been darted with PZP for nearly two decades.  Yet roundups have been scheduled there like clockwork every 3 years and, in spite of intensifying the PZP treatments recently, BoLM tried to implement yearly roundups until stopped by a Friends of Animals lawsuit.

PZP — the anti-vaccine:  PZP causes disease — auto-immune disease.  PZP “works” by tricking the immune system into producing antibodies that target and attack the ovaries.  The antibodies cause ovarian dystrophy, oophoritis (inflammation of the ovaries), ovarian cysts, destruction of oocytes in growing follicles, and depletion of resting follicles.  The mare’s estrogen-levels drop markedly as PZP destroys her ovaries.  Ultimately, PZP sterilizes her.  Because PZP stimulates the immune system, it ironically works “best” — sterilizes faster — in mares that have strong immune-function.  Such mares respond to the anti-vaccine and produce quantities of PZP antibodies that destroy their ovaries.  But, conversely, PZP may not work at all in mares whose immune-function is weak or depressed.  Those mares fail to respond to PZP.  They keep getting pregnant and producing foals who, like their dams, suffer from weak immune-function.  So, the PZP pesticide works against the very horses that Nature has best equipped for survival-against-disease while favoring and selecting for the immuno-compromised.  Worse yet, radioimmunoassay tests indicated that PZP antibodies are transferred from mother to female offspring via the placenta and milk.

Health-risks to volunteers:  As for the well-meaning volunteers who dart wild horses, EPA’s Pesticide Fact Sheet for PZP advises that Personal Protective Equipment requirements include long sleeved shirt and long pants, gloves and shoes plus socks to mitigate occupational exposure.  EPA specifically warns that pregnant women must not be involved in handling or injecting ZonaStat-H, and that all women should be aware that accidental self-injection may cause infertility.  Unfortunately, PZP’s manufacturer misrepresented PZP as “so safe it is boring.”   But research shows that PZP is a powerful hormone disruptor.  Further, consider the magnitude of the risk — the PZP-in-question is a horse-sized dose.  If volunteers think PZP is safe, they will be less likely to protect themselves from this dangerous pesticide.

Mengelian experiments:  The Big Lie of “overpopulation” is the pretext for BoLM’s war against the wild horses, and the wild horses are prisoners of that war.  It’s BoLM’s version of the “Shock Doctrine,” wherein the agency concocted a phony crisis to push through policies antithetical to the Wild Horse Act against the will of The People.  Now, BoLM is funding surgical-sterilization studies on the equine POWs to develop a Final Solution to the “problem” — handing out $11 million for these diabolical experiments.  The grant money is surely intended to buy loyalty and silence potential criticism from academia.  Plus, BoLM, a corrupt, rogue agency, gets to cloak itself in respectability by affiliating with prestigious universities.

Should you wish to learn more about how BoLM is mismanaging Arizona’s wild burros, I would be happy to send you a copy of comments recently submitted.  Just let me know.


Marybeth Devlin

Miami, FL

Protect Mustangs is a 501c3 nonprofit organization who protects and preserves native and wild horses.

#Pesticide PZP is dangerous for the last American herds of wild horses and burros

PM PZP Injection

The old hypothesis — that PZP merely blocks sperm attachment — has been disproved.

Kaur & Prabha (2014) found that the infertility brought on by PZP is ” … a consequence of ovarian dystrophy rather than inhibition of sperm-oocyte interaction.” They reported that PZP’s antibodies induce ovarian dystrophy, oophoritis (inflammation of the ovaries), destruction of oocytes in all growing follicles, and depletion of resting follicles.

Despite all the hype about PZP being non-hormonal, the manufacturer himself knew that it had an adverse hormonal effect — significantly-lowered estrogen. In 1992, he reported that ” … three consecutive years of PZP treatment may interfere with normal ovarian function as shown by markedly depressed oestrogen secretion.” Thus, PZP is an endocrine disruptor.

Worse yet, Sacco et al. (1981) found that PZP antibodies are transferred from mother to young via the placenta and milk. The transferred antibodies cross-react with and bind to the zonae pellucidae of female offspring. This is bad news because BLM regularly administers PZP to pregnant and lactating mares, who transfer the destructive antibodies to their filly-foals. Thus, the fillies get their first treatment with PZP in utero, while nursing, or both.

Nettles (1997) found an association between PZP and stillbirths. In 2015, the International Society for the Protection of Mustangs and Burros reported that 7 mares previously treated with PZP, when taken off it, were able to get pregnant. However, 6 of those 7 mares — that is, 86 percent — produced foals that were stillborn. All other ISPMB mares that had not been previously injected with PZP successfully birthed healthy foals. Environmental and other conditions were identical. The only variable was PZP. Meanwhile, over on the East Coast, the Corolla herd, long-managed with PZP, has recently experienced birth defects among its newborns.

Gray & Cameron (2010) questioned the supposed benefit of PZP-sterilized mares living much longer than their normal life expectancy, and and Knight & Rubenstein (2014) warned of unintended consequences of PZP’s ironic effect of extended longevity. Ultra-elderly mares take up scarce slots within AML-restricted herds. They consume resources but no longer contribute to the gene-pool. It is detrimental to a population’s genetic viability to carry significant numbers of sterile herd-members way-beyond their normal life-span. Meanwhile, those few foals that are born have to be removed to achieve AML because they’re more adoptable.

Ransom et al. (2013) conducted a longitudinal study of three herds currently being managed by PZP — Little Book Cliffs, McCullough Peaks, and Pryor Mountain. They found that the the birthing season lasted 341 days — nearly year-round — which puts the life of mares and foals in jeopardy. Nature designed the equine birthing-season to occur in Spring, not year-round, and certainly not in the dead of Winter.

Ransom et al. also found that, after suspension of PZP, there was a delay lasting 411.3 days (1.13 years) per each year-of-treatment before mares recovered their fertility. They warned: “Humans are increasingly attempting to manage the planet’s wildlife and habitats with new tools that are often not fully understood. The transient nature of the immunocontraceptive PZP can manifest into extraordinary persistence of infertility with repeated vaccinations, and ultimately can alter birth phenology in horses. This persistence may be of benefit for managing overabundant wildlife, but also suggests caution for use in small refugia or breeding facilities maintained for repatriation of rare species.”

PZP’s manufacturer conceded that it could take up to eight years to recover fertility after just three consecutive PZP treatments.

The study on PZP by Knight & Rubenstein (2014) found that ” … three or more consecutive years of treatment or administration of the first dose before sexual maturity may have triggered infertility in some mares.” These findings are particularly troubling. They suggest that, actually, only two consecutive PZP-treatments may be reversible. Except, that is, in the case of fillies who have not yet reached puberty — they could be sterilized by just one injection.

PZP’s manufacturer was quoted describing PZP as “so safe it is boring.” Independent research shows otherwise — that PZP is a powerful hormone disruptor that could sterilize a female with just one injection. If staff and volunteers believe that PZP is boringly safe, they will be less likely to protect themselves adequately from this dangerous pesticide. Indeed, many of the volunteers are women and, therefore, at risk. Accidental self-injection with PZP could cause them to suffer diseased ovaries and depressed estrogen-levels — in addition to infertility and, potentially, sterility. Consider the magnitude of the risk — the PZP-in-question is a horse-size dose.

~ Marybeth Devlin, Wild Horse Advocate

Protect Mustangs is an organization who protects and preserves native and wild horses.