Wild Horse Education

Burros, Burros, Burros

This weekend, after a summer of watching relentless removals of wild horses from public lands, let’s not forget the burros.

The winter roundup schedule places Black Mountain in Arizona on target for a capture of 1,000 and the small Canyonlands in Utah on tap for a removal of 40. Both are scheduled as helicopter drive-trapping in January and February,

A massive Gather-Environmental Assessment (EA) for Three Rivers is open for comment until October 11. We alerted you to this plan a couple of weeks ago and began to give you some information as you craft your comments (HERE).

We volunteer Laurie Ford sent the following submission to give you more info to make a stand. We present her full essay below, without edit.

If you are planning to comment, we suggest grabbing the EA HERE and following along. You can pull notes from Laurie and submit a comment through the “Participate Now” button on the BLM webpage. 

A long read for the long ears.

In 2020 The BLM Advisory Board recommended BLM identify the behavioral, physiological, and social differences between wild horses and burros that would allow them to expand the program’s capabilities to manage burro populations humanely and appropriately. BLM has yet to follow this recommendation. And, as studies also lag regarding the habitat loss and wildlife mortality associated with the rapid construction and infrastructure of renewable energy one wonders where does this leave our wild horses and burros?

The BLM wants to remove almost 85% of the burros in the Three Rivers Complex – 36% of the remaining population in Arizona – and allow only 90-95 fertile jennies to remain on the range that have been fitted with, if BLM gets their way, radio collars. Afterwards, over the ensuing 10 years, they will have carte blanche to continue removing burros with no oversight. While by law, the BLM is supposed to be managing the burros in balance with other uses and considering them comparably with other resource values (CF4700.0-6) they will continue to ignore the impacts of exploding urban expansion, outdoor recreation and renewable energy development on the population growth, migration, survival rates, and mortality of the very same burros.

It is a dangerous balancing act the BLM is performing to keep their unscientific 10-year management plan alive and well and fully funded. While keeping the annual herd numbers in a constant state of overpopulation – at least on a spreadsheet – they must also show that progress is being made towards reaching AML.

It is our responsibility to question and challenge these current methods of management based on antiquated land-use plans, multiple uses, data and studies.  Commenting on EAs allows us to do this.

(You can access more info and a link to the EA to comment HERE)

The future of our wild burros is based on a single number – the March 1 annual estimated HMA population (listed under BLM Program Data) formulated from two sources; the application of an annual 15%-25% growth rate on the current population and the analysis of aerial survey data when the number of burros sited is typically increased by 25% to account for those “present but not seen”.  Both methods are flawed, inconsistent and unreliable resulting in values that often differ by hundreds, even thousands – especially in complexes that involve a number of HMAs such as the Three Rivers Complex where there is continual migration between the HMAs throughout the year and large numbers of burros that temporarily, sometimes permanently, reside outside of the HMA boundaries.

The aerial survey data takes precedence over the latest annual estimated population. From that point on the annual growth rate continues to be applied to the new estimated population derived from the survey and the numbers will, once again, start to artificially increase.

The following are just 2 examples from the Three Rivers Complex of the differences that can arise from these two methods. By evaluating program historical data, you can discover many more.

On 3/1/2021, having applied the 15% growth rate over the years, the population of the Three Rivers Complex had soured to 3346.  8 months later, an aerial survey estimated the same population to be 1731 – a 1600 burro difference. While this decrease appears to be a good thing what If an aerial survey had not been conducted and removals proceeded based on the 3346 number?

On 3/1/2020 the estimated population for the Havasu HMA was 172. Since then 327 have been removed yet today, based on the aerial survey data, the pop has increased to 402 – the number that will now predicate removals within the HMA to reach AML. In this instance the population reflected an increase in the HMA despite many nuisance gathers having taken place over recent years.

Knowing that female burro’s foal year-round, have gestation periods lasting up to 14 months and DO NOT produce a foal every year the BLM continues to apply a 15% growth rate to the Three River Complex – noted in the EA as a typical and reasonable expectation.

Factors such as weather, water availability, forage availability, animal behavior, and the administration of fertility control can all increase the amount of time needed to reach AML. (pg. 4)

While the BLM acknowledges these factors impact their ability to reach AML it appears none seem to affect reproduction, survival or mortality rates.  Studies conducted outside of the BLM have proven, without a doubt, something quite differently and even the USGS has determined that applying past growth rates to future populations is not in the best interest for accuracy. But, for the BLM it is the easiest option.

Claims by the BLM that 95% of foals survive, and burros live well into their 30’s, have also been debunked by outside studies and by their very own data obtained through FOIA requests that reveal minimal numbers of very young, or very old, burros in holding facilities.

In the wild foals can nurse up to a year and will remain with the mother and her herd well after being weaned. If you examine past burro gathers spanning almost every month over the years rarely do foals account for or represent close to 10% of the total take. Gathers that took place in the Black Mountain HMA, during winter, spring, summer and fall of 2022/2023, only reflected a take of 9.5% foals so why does the BLM continue to use the 15% as the standard growth rate?

Even the 2021 aerial survey of the Three Rivers Complex only estimated 7.68% of the population were foals.

When burros or horses continually migrate between HMAs within a complex it is impossible to derive true HMA population numbers – the number used in determining removals to reach, and retain, AML – outside of a very narrow timeframe. Due to the constant fluctuation of these numbers an HMA could be within AML one day, under the next and then over a month later.

The EA briefly touches on known seasonal movements of the burros within the HMA’s (pg.9), and that during the hot summer months, some wild burros are residing permanently outside the HMA (pg.3) Where is the data monitoring these movements and the impact on HMA populations? Where are the studies on why and when this migration takes place? Is it because of forage or water availability or pressure from other multiple uses such as outdoor recreation, mining or the recent renewable energy development?

To reach AML, it is currently estimated that 1,794 excess wild burros would be removed from areas in and adjacent to the HMA’s (approximately 1,247 burros from the Alamo HMA, approximately 283 burros from the Big Sandy HMA and approximately 264 burros from the Lake Havasu HMA). All excess wild burros residing in areas outside of the HMA’s would be gathered and removed(pg.8)

With the constant movement this is totally unrealistic. In addition, the wording allows EVERY burro – not just the estimated 706 burros outside of HMAs sited in the EA – to be removed. As the burros migrate between HMAs – burros that had been previously included in a specific HMA removal number – they could end up being “double removed”.

Burros outside of, or those on private within, the HMA can also be removed at any time under the guise of a nuisance gather – based solely on a “written request” that “shall indicate the numbers of wild horses or burros” (43 C.F.R. § 4720.2-1). Hundreds of burros within the complex have been removed over the past in this manner.

Once AML is reached, BLM would maintain approximately 60% males and 40 % females in each HMA to achieve a 60/40 male to female sex ratio (66 females Lake Havasu HMA, 55 females Big Sandy HMA, 64 females Alamo Lake HMA). BLM would gather up to 50% of the remaining female burros in each HMA (33 females Lake Havasu HMA, 28 females Big Sandy HMA, 32 females Alamo Lake HMA) and administer fertility control vaccines using the most current approved formula.8 BLM would conduct subsequent maintenance gathers as necessary over the 10-year period to remove additional wild burros to maintain the population at AML.8

Aware of the continual movement the BLM still wants to skew the sex ration of each HMA knowing that one month later it can change due to migration. What if all the fertile jennies migrate to another HMA leaving the HMA behind void of any reproducing females? An unbalanced sex ratio in favor of males would cause the minimum number of burros required for genetic variability and health to be increased.

The target removal numbers for follow-up gathers, fertility treatments, and sex ratio adjustments would be adjusted based on periodic monitoring and population inventories for the Three Rivers Complex

The BLM will still be using a population modeling software such as Pop Equus (Folt et al. 2023;  assuming that model’s capabilities will be expanded to include burro population projections) to help inform expectations about how many animals in future gathers or actions should be removed, or jennies treated, in order to achieve herd management goals. (pg. 15)

In short, periodic monitoring and population inventories over the next 10 years will continue to rely on flawed methods that help leave the door open for the BLM to continue removing burros as the HMAs remain in a constant state of “overpopulation”.

Through “management” the BLM also contributes to ongoing “overpopulation” by destroying the ways life and death are controlled naturally and replacing them with unnatural means that intentionally increase reproduction and reduce deaths by elimination competition.

As a result of lower density of wild burros across the HMA’s following the removal of excess burros, competition for resources would be reduced. Because there would be lower levels of competition for forage resources, burros that remain on the HMA’s would have relatively more access to preferred, quality habitat. Confrontations between jacks would also become less frequent, as would fighting among wild burros at water sources. Achieving the AML’s and improving the overall health and fitness of wild burros could also increase foaling rates and foaling survival rates over the current conditions. Injuries and death to all age classes of animals would be expected to be reduced as competition for limited forage and water resources is decreased. (pg. 32)

Also, in a constant state of overpopulation will be the holding facilities.

No identified “long term pasture facilities” exist for wild burros. As we head into winter, and hay and grain prices continue to soar, the BLM is currently warehousing 1400 – almost half of the burros rounded up last year – in preparation facilities. Of these burros 735 are located at the Florence, AZ, facility – with a capacity of 1000 – where the 1793 Three Rivers Complex burros removed will most likely be sent.

So, what happened to the other estimated 1600-1700 burros rounded up in FY 2022?

The BLM claims they have all gone to wonderful, thoroughly vetted loving homes. Most likely many are dead.

Across all BLM burro gathers in 2010-2019, total gather-related mortality averaged less than 0.1%, which is very low when handling wild animals (Scasta 2020); this rate reflects acute mortality at gathers. Another 0.2% or less of the burros captured were humanely euthanized due to pre-existing conditions and in accordance with BLM policy (Scasta 2020) (pg. 30)   

Prior to 2019 most wild burros were captured using bait and trap methods. In 2019 almost 1700 were removed using this method including the Bullfrog HMA roundup of 690 when only 1 death took place. Why is more recent data from helicopter roundups not being used when discussing mortality?

After the wild burros have transitioned to their new environment in the holding facility, they are prepared for adoption or sale in accordance with BLM policy. Likelihood of injury or mortality during the preparation process is low but can occur. Mortality of wild horses and burros at short-term holding facilities averages approximately 5% (Government Accountability Office 2008) and includes animals euthanized due to a pre-existing condition, animals in extremely poor condition, animals that are injured and would not recover, animals which are unable to transition to feed; and animals which die accidentally during sorting, handling, or preparation.  (pg.31)

Data regarding deaths that take place after roundups is never disclosed in EAs nor is it posted under program data. The above statement briefly touches on antiquated data from 2008 when, one year later, only 306 burros were gathered using the bait and trap method. The only way to obtain real death numbers is through the slow and tedious process of submitting FOIAs.

Despite the BLM knowing full well it increases stress levels and poses life threatening health risks for burros – both of which persist long after the roundup is over as burros are separated, processed, transported and even after adoption – helicopters will be used in the Three Rivers Complex roundup.

Because burros travel alone or in small groups helicopters are required to gather and push them over longer distances to the trap where they are often herded directly onto trailers.  Adults scatter and foals got separated requiring aggressive roping that exasperates already existing stress levels.

Throughout The EA, while acknowledging the roundup can lead to stress, the BLM continues to downplay and distort the potential impacts to individual wild burros from handling stress.

By utilizing the measures included in the CAWP the likelihood of stress or injury to burros is minimized.

Burros typically calm down quickly (within a few minutes of the capture crew’s arrival), whether the trap method is bait trapping or helicopter drive trapping

Boyd et al. (2016) wrote that there are “…no permanent or long-lasting bonds between any two individuals other than between an adult female and her current foal.”

Stress on the males and/or the mother/foal pairs is expected to be minor and temporary. (pg.29)

The existence of CAWP has not minimized stress and injuries , burros’ are not “calming down” but rather doing what comes naturally to them by remaining stoic as they assess the surrounding situation, and  the statement that burros do not establish long-lasting bonds can be easily disputed by any person who has witnessed the strong and lifelong bonds that exist among burros. Separation can be life threatening.

An especially important difference is that while all equines can develop hyperlipemia – defined as an excess of lipids in the blood. – donkeys are more prone to developing it, particularly in regards to the extreme stress of losing or being separated from a companion. (Equine Veterinary Education)

The EA goes on to claim stress is minor and temporary and that stress on these animals is expected to last less than a few hours after processing is completed (pg.31) revealing a total failure of the BLM to study and understand the burros they manage, and examine the data that portrays something quite differently – that a large number of  stress related deaths take place in holding and after the burro is purchased or adopted.

Shortly after capture wild burros are vaccinated, wormed and all apparent health conditions addressed. If the burro shows signs of sickness, failing health, or an infirmity, disease, injury, lameness, or serious physical condition or defect that has a poor prognosis for improvement or little chance of recovery they are euthanized.

Males – whose penises are typically larger than that of a horse – are also gelded when an alarming number hemorrhage and die. But, capture induced stress, and the ensuing weakening of the immune system and other life-threatening maladies, is not acknowledged or treated despite its ability to easily turn chronic. When this takes place, the BLM refers to the instances as acute or chronic problems that can develop during the captivity and handling of wild animals that must be humanely addressed by euthanasia.

The main cause of death after capture is hyperlipidemia and can occur rapidly or over time as the stress persists. Stress, when combined with a pre-existing non-life-threatening illness, separation or exposure to a totally new environment and unnatural diet, often causes inappetence in a burro putting them in a negative energy balance. In response, the body starts to mobilize fat reserves as an energy source causing excess fat in the bloodstream to infiltrate the organs and lead to organ failure and death. The simple release of stress hormones alone can also promote this mobilization of deadly excess fat.  Pregnant jennies are especially prone to hyperlipidemia due to their extra energy needs.

Yet the BLM prefers to frame this main cause of death as follows:

Recently captured wild burros, generally females, in very thin condition may have difficulty transitioning to feed. A small percentage of animals can die during this transition; however, some of these animals that do die during transition are in such poor condition that it is unlikely they would have survived if left on the range. (pg.31)

To blame these deaths on “being thin” and claim death would have occurred regardless is an absolute distortion of the truth. I have rarely observed thin burros on the range, during a roundup or in holding and I have seen thousands.

I have also never seen “being thin” as cause of death in BLM documents.  Necropsies provided in FOIAs reveal jennies that died from hyperlipidemia as being in good body condition and often site “changes associated with a variety of stresses” as a contributing factor to death.

Because a necropsy is required to diagnose hyperlipidemia the manner of death is routinely listed as unknown, chronic or following long illness, failure to thrive, foaling complications or simply found dead.

A jenny’s stress can also affect the fetal development of her foal and the period during and after birth which could result in severe neonatal illness or death.

Just last year 46 burros died (almost 6%) shortly after the Blue Wing roundup. It was confirmed that 26 jennies died from hyperlipidemia and 6 jacks from hemorrhaging after gelding. It is too early to obtain information regarding the numbers who have died after being adopted.

After a 2020 Selenite nuisance gather within the same complex 38 (17.5%) have been confirmed dead – 6.5% within 2 months of capture.

Following the 2022 Sinbad roundup 24 (15.89%) died – most within 30 days and some within only hours. Half were listed as foaling complications – the pregnancy doomed by hyperlipidemia. 7 males died as a result of hemorrhaging from castration.

Multiple FOIAs have provided a sufficient sample size revealing approximately 20% – 30% or more burros die within 1 year of capture either in holding or after adoption.

The BLM is also considering putting radio collars on up to 100 jennies – over half that will be remaining on the Complex. The EA is not clear whether they will be used on those jennies that have, or have not been, administered fertility control.

Collars would be fit onto fewer than 100 burros over the 10-year period, with no more than 40 attached after any given gather. The GPS radio collars (< 1 kg) would be programmed to collect one or more locations per day. The collars are designed to prevent negative impacts to burro welfare and are expected to detach within 3 years. Collars are solid-battery powered and will include a very-high frequency (VHF) transmitter to facilitate unit location and recovery. (pg.33)

This was tried in 2016 on the Sinbad wild burros when 30 jennies were fitted with timed release radio collars – somewhat resembling the yoke worn around a working animal’s neck – that were intended to fall off before the batteries expired in 5 years. The collars – also enabled with a remote release – would be removed during the next roundup in the case technology failed. Long-term collars had never previously been tested on wild burros yet the possibility of associated mortality was understood.

During the 2022 Sinbad roundup 3 jennies captured were still wearing the 2016 radio collars whose batteries had died long ago and 7 whose collars had dropped off leaving 14 collared jennies from 2016 still unaccounted for.

All collared jennies would be monitored visually every 4-6 weeks, to confirm that no abrasions are occurring. Collars may be fitted too tightly, or a burro might grow, tightening the collar. If these situations are observed, the UHF remote-release function would be deployed remotely. If the remote-release drop-off failed, the collar could be removed after capturing the animal through approved methods part of the Proposed Action. Serious neck abrasions or sores have not been (pg.33)

This also is unrealistic. How is the BLM going to monitor these burros every 4-6 weeks? If the remote release fails how are they going to capture that jenny? If the technology fails how are they even going to locate the jenny?

Lastly, before administering any fertility control further studies on wild burros must be conducted rather than relying on those past studies involving wild horses which are limited in themselves. The BLM’s  continual reference to “their experience” with administering fertility control to wild burros, and inserting the word “jennies” when the information is only applicable to horses,  is totally misleading as any such research of wild jennies and fertility control being discussed has never been documented  which is why the BLM repeatedly uses the word  “assumed.”


Our teams are working hard in field and trying to shore up information on how the looming shutdown will impact removal operations, appeals and litigation.

We have submitted a request for extension of time to comment (the time the shutdown lasts plus 14 days to deal with the chaos it causes).

For now, the deadline to comment is October 11.

We are working to get this comment period and others extended.


Our wild ones should live free on the range with the families they hold dear. Our wild ones should also live without abuse. WHE carries ongoing litigation to force BLM into open public process to create an enforceable welfare standard for our treasured wild ones. 

Thank you for keeping us in the fight!

As holiday shopping begins, you might be able to find a gift for yourself or the horse lover in your life at our WHE storefront on Zazzle. All proceeds support our work for our wild ones. HERE. 

Categories: Wild Horse Education