photo: Carol J. Walker
We are posting researcher Marybeth Devlin’s comments the the BLM’s National Wild Horse & Burro Advisory Board are below:
Sterilization-Study — Predicated on Fraudulent Claim of Overpopulation
BLM uses “overpopulation” as its reason to conduct population-suppression research. However, the alleged overpopulation of wild horses is a pernicious lie, a concocted crisis, particularly in Oregon. BLM is targeting the Warm Springs herd for these experiments.
The Warm Springs Herd’s Arbitrary Management Level ( High-AML)
According to BLM, the maximum number of wild horses that the 499,457 acres (780 square miles) composing the Warm Springs habitat can sustain is 178. That number represents a recent 12% reduction from the original high-AML of 202. Such numbers are not environmental requirements but rather political constructs, set for administrative convenience and political expediency. The reduced upper bound of the Warm Springs AML establishes a maximum stocking density of 1 wild horse per 2,806 acres — nearly 4.4 square miles.
The Warm Springs Herd’s Austere Management Level (Low-AML)
BLM does not manage up to the maximum but rather down to the minimum, that is, down to the low bound of the AML — 96. That number reflects a recent 13.5% reduction from the original low-AML of 111. As with the high-AML, the low-AML is not a scientifically-determined number. This even-more austere management level corresponds to a stocking density of 1 wild horse per 5,204 acres — well over 8 square miles.
Sparsely Populated, Widely Dispersed
Obviously, BLM aims to keep the Warm Spring wild horses few and far between. The paltry stocking-density is designed to easily create the false impression of an overpopulation when, in fact, even when over the AML, the herd is underpopulated.
Warm Springs is not alone. Listed below are other herds in Oregon that are also restricted by sparse stocking densities, down-to-which BLM culls these herds:
1 wild horse per 2,073 acres — 3.2 square miles — Sand Springs
1 wild horse per 2,302 acres — 3.6 square miles — Stinking Water
1 wild horse per 2,320 acres — 3.6 square miles — Palomino Butte
1 wild horse per 2,832 acres — 4.4 square miles — Pokegama
1 wild horse per 2,885 acres — 4.5 square miles — Liggett Table
1 wild horse per 2,972 acres — 4.6 square miles — Coyote Lake / Alvord Tule
1 wild horse per 4,381 acres — 6.8 square miles — Beatys Butte
1 wild horse per 5,062 acres — 7.9 square miles — Paisley Desert
Long Gestation — Delay in Beginning Reproduction — Alternate Year Foaling
Horses are a slow-growth species when it comes to reproduction. The gestation-period lasts an average of 11.2 months, and a mare produces just 1 foal. There is a delay of two or — usually — three years before fillies begin to produce foals (National Research Council 1980, citing Eberhardt et al. 1982, and Garrott and Taylor 1990). Further, there is evidence that wild mares tend to foal every other year, likely due to inadequate energy-reserves to sustain a pregnancy every year (NRC 1980).
The Birth Rate ≠ The Herd-Growth Rate
Generally, BLM has been misusing the birth rate as a proxy for the herd-growth rate. However, the birth rate and the herd-growth rate are two different measures. For a herd-growth rate to be valid, the birth rate must be reduced by the respective death rates for foals and for wild horses other-than-foals.
The birth rate among wild-horse herds not managed with contraceptives was found to average 17% to 20%; but within a year, between 32% and 50% of those foals vanish (McCort 1984, citing NRC 1980; and Gregg et al. 2014). Thus, the birth rate is just a temporary blip in the data. Only 50% to 68% of foals survive to become yearlings.
Adult-Mortality Must Also Be Factored
Meanwhile, the mortality rate (extrapolated from the survival rate) for wild horses other-than-foals ranges from 3% to 20%, with a median of 11.5% (BLM Smoke Creek EA 2017, citing Wolfe 1980, Eberhardt et al. 1982, Garrott and Taylor 1990). That 11.5% can be deemed a reasonable estimate of adult mortality among free wild horses is supported by two statements, found in recent BLM environmental assessments regarding captive wild horses kept in long-term, off-range pastures (ORPs):
1. “Natural mortality of wild horses in ORP averages approximately 8% per year ….” and
2. “Wild horses residing on ORP facilities live longer, on the average, than wild horses residing on public rangelands ….”
Expected Annual Growth, Even with Percentages Rounded to Favor Growth
Birth rate: 17% to 20% — Midpoint: 18.5% — Rounded up: 20%
Foal-survival rate: 50% to 68% — Midpoint: 59.0% — Rounded up: 60%
Adult-mortality rate: 3% to 20% — Midpoint: 11.5% — Rounded down: 10%
For a hypothetical herd of 100 horses, we would calculate the high-normative growth-rate as follows:
60%[20%(100)] − [10%(100)] = ?
60%(20) − 10 = ?
12 − 10 = 2 and …
2/100 = 2%
If we used NRC‘s findings — 17% foaling rate, 68% survival rate — the growth rate would be 1.6%. If we used Gregg et al.’s findings — 20% foaling rate, 50% survival rate — the growth rate would be 0%.
BLM Deceptively Uses the Birth Rate as the Population-Growth Rate
BLM officially cites “20%” as the average population-growth rate; but 20% is actually the high end of the unadjusted birth rate. Please note that 20% is 10 times the expected growth rate.
BLM’s Herd-Growth Figures Were Not Backed Up by Source Data
BLM’s updated sterilization-study EA cited the 2013 National Research Council’s (NRC) report as the authority for its claim of a 20% annual growth rate. However, the NRC Committee had no choice but to accept BLM’s alleged population-growth rate. Why? Because, as the NRC complained in its report, BLM failed to meet the Committee’s data-requests, provided incomplete records in many instances, and lacked data supporting the national population statistics.
“The committee found that a substantial proportion of the HMA estimates published by the national office did not correspond to the ones the committee received from the field offices; discrepancies ranged from modest to many hundreds of animals.”
BLM told the NAS that it had discarded the records. The absence of the back-up documents prevented the researchers from tracing data-discrepancies to their source.
Invalid Year-to-Year Population-Growth Data
Because the subject EA targets the Warm Springs horses for sterilization per an alleged high reproductive rate, let’s review what BLM claimed were the herd’s annual growth rates in recent years. The chart below tracks BLM’s reported population-growth figures for the Warm Springs herd as of March 1 of each year since 2010, the year that will serve as the base, the starting point. Note that contraceptive treatment (PZP) should have significantly reduced the growth-rate; but BLM ignored that effect.
2010 — 362 — November 2010 cull. PZP given
2011 — 111
2012 — 133 — 20% — 10 times the 2% high-norm despite PZP
2013 — 160 — 20% — 10 times high-norm
2014 — 192 — 20% — 10 times high-norm
2015 — 368 — 92% — 46 times high-norm
2016 — 442 — 20% — 10 times high-norm
2017 — 586 — 33% — 17 times high-norm
2018 — 739 — 26% — 13 times high-norm
2018 — 886 — 20% — 10 times high-norm — after the foaling season.
Note that the biologically-implausible growth rates compound, as each successive year is calculated per those that preceded it. It is according to these falsified growth rates that BLM claims an overpopulation, one that would appear to double every four years … or sooner (note the 92% increase that BLM reported in 2015). However, per the true high-normative growth rate of 2%, it would take 35 years for a herd to double.
Falsified Herd-Growth Rates Found in BLM Reports for Oregon
Warm Springs is not the only herd in Oregon whose year-to-year population increases defy credulity. It is important to consider the others because BLM claims one of the objectives of its experiments is to determine the feasibility of sterilizing the mares of additional herds that it claims are overpopulated. Thus, BLM aims to set a precedent. Below are some of BLM’s fraudulent one-year herd-growth rates:
101% — 50 times high-norm — South Steens
102% — 51 times high-norm — Pokegama
104% — 52 times high-norm — Palomino Butte
170% — 85 times high-norm — Stinking Water
179% — 90 times high-norm — Paisley Desert
256% — 128 times high-norm — Beatys Butte
317% — 159 times high-norm — Jackies Butte
Fraud Is a Crime
BLM’s representations with regard to Oregon’s wild horses are false and misleading. Making false and misleading representations = fraud, which violates Title 18 USC 1001 of the Federal criminal code. Embezzlement and theft — expenditures of government funds for fraudulent reasons — violate various sections of Title 18 USC Chapter 31.
Pattern of Fraudulent Reporting, Leading to Misuse of Government Funds
There also seems to be a pattern to this fraud. It appears to extend across BLM field offices, district offices, the state office, and the National Office. BLM offices in other states have also reported fraudulent wild-horse herd-growth rates.
As American citizens, we expect our government officials to administer programs and funds honestly. In Oregon and elsewhere, BLM appears to coordinate the reporting of fictitious figures to secure increased funding to solve a phony problem.