The feds’ mustang population “data” is a fraud
By Marybeth Devlin
While pretending to rely on the assumption that herds grow 20% a year, the Bureau of Land Management (BLM) posts numbers up to 8 times higher than that to justify roundups, which are pre-scheduled on a rotation-basis, seeming to target particular herds. For instance, the Agency recently claimed that the famous Kiger herd in Oregon grew from 21 horses to 156 horses in just four years — an increase of 643%, which equates to a yearly average increase of 160%, which is 8 times higher than the 20% BLM supposedly uses.  Such growth is biologically impossible. Kiger is not an isolated example, although it is the worst found so far. Here are some other phony figures on population-growth recently claimed by BLM to make it appear that gathers were necessary:
Blawn Wash (UT)
297.4 % increase in 3 years, averaging 99.1 % per year
Fish Creek (NV)
80% increase in one year
Green Mountain (WY)
281% increase in four years, averaging 70.3% per year
Stewart Creek (WY)
311% increase in four years, averaging 77.8% per year
But herd-growth is unlikely to reach even 20 percent a year. It is important to understand that the birth-rate is not the same as–and should not be equated to–the population growth-rate. Here’s why: Horses die. An independent study reviewed BLM roundup-records for a representative sample of four herd management areas composed of 5,859 wild horses (Gregg, LeBlanc, and Johnston, 2014). While the researchers found an overall birth-rate of just under 20 percent, they also found that half of foals perish in their first year of life. Thus, the effective foal-to-yearling survival-rate is just 10 percent. Further, adult wild horses also perish. They succumb to illness, injury, and predation. Their death-rate must be taken into consideration as well. But BLM ignores mortality–foal and adult–in its population-estimates. Given the 50% foal mortality-rate, and the 5% or higher average annual death-rate of adult wild horses, herd-growth could not increase 20% a year, and a herd-population could not double in 4 years–refuting yet another BLM myth.
Stealthily inserting bogus birth-rates into the data, wrongly conflating birth-rates with population growth-rates, and failing to factor in mortality-rates–that is how BLM creates the false impression of a population-explosion. But “cooking the books” is not the only way BLM falsifies the population-picture. Another ruse BLM employs is restricting maximum herd-size below minimum-viable population (MVP) size. Then, whenever a herd is made to appear–via fictitious figures–to exceed the arbitrary management level, BLM screams “excess!” and declares an immediate need for mass-removals and sterilizations. It should be noted that more than 70 percent of the herds are “managed” below MVP.
BLM also fails to consider another factor limiting herd-growth–stochastic events–which are random catastrophes such as wildfires or contagious diseases that suddenly wipe out mass-numbers of herd-members. Stochastic events can result in no-growth or even negative growth.
Now BLM is distributing grant-money to universities and researchers to study more ways of dealing with the phantom overpopulation. All manner of sicko experiments are being carried out on the wild horses, such as treating them with endocrine disruptors and sterilizing them surgically. Why? Because BLM is a corrupt agency. It invented this counterfeit crisis to create a sense of urgency, which will pressure Congress to give the Agency extra money to “solve” a non-existent problem.
TAKE ACTION: Sign and share by email the Petition to Stop the Wild Horse and Burro Roundups and Slaughter here: https://www.change.org/p/defund-and-stop-the-wild-horse-amp-burro-roundups
Contact your elected officials to make them aware of BLM’s fraudulent population claims to get funding for wild horse roundups and warehousing at great taxpayer expense: http://www.contactingthecongress.org
Click “Like” https://www.facebook.com/ProtectMustangs for updates and alerts
Visit www.ProtectMustangs.org for more information and click on the donate button help fight the injustice! You can make a difference.
Protect Mustangs is a nonprofit organization who protects and preserves native and wild horses.
(Photo by BLM. Roundup paid for with your tax dollars.)
 Using simple division to calculate the average increase is how most people would “do the math”–dividing the percentage increase (643%) by the number of years (4). Expressing the average that way is readily understandable. However, another way of calculating it is what is called the “compound annual growth rate” (CAGR). Per that method, herd-growth can be likened to compound interest that you earn on a savings account; except of course that horses do die, which complicates the computations. But for now, let’s assume that horses never die, because that’s the assumption that BLM makes.
Using the free, online CAGR tool linked below, you would enter Kiger’s beginning population–21–and its alleged ending population–156–and the number of years that had passed–4. Then press the “Calculate CAGR” button, and the tool will compute the compound annual growth rate. For the Kiger herd, the CAGR is 65%, which is “only” 3.25 times higher–instead of 8 times higher–than 20%.
Here is the tool to compute CAGR:
Here are the other herds cited and their CAGRs. Fish Creek stays the same because its growth is just for one year.
Blawn Wash (UT)
38 = Population-estimate 2012
151 = Population-estimate 2014, including new foals
297.4 % = Percentage increase in three years
99.1 % = Simple average annual growth-rate
58.4 % = Compound annual growth-rate (CAGR)
Fish Creek (NV)
256 = Population-estimate 2013
461 = Population-estimate 2014, before foaling season (January)
80.1% = Percentage increase in one year
Green Mountain (WY)
258 = Population-estimate post-gather at the end of 2011
982 = Population-estimate in 2015 — including that year’s foals*
281.0 % = Percentage increase in four years
70.3 % = Simple average annual growth-rate
39.7 % = Compound annual growth-rate (CAGR)
124 = Population-estimate post-gather at the end of 2011
509 = Population-estimate in 2015 — including that year’s foals*
311.0 % = Percentage increase in four years
77.8 % = Simple average annual growth-rate
42.3 % = Compound annual growth-rate (CAGR)
* BLM’s population-modeling criteria said foals were not included in the AML. Evidently, they were.
Further Insight into Calculating Population-Growth
At the link below, you will find a discussion posted by the University of Oregon, providing a comparison between the simple average and the compound annual growth-rate methodologies for calculating annual percentage population-growth.
As will be readily apparent, the simple average approach is “straight-line” and … simple. Forgive yet another pun, but the average person can easily understand it and “do the math.”
The compound annual method, on the other hand, is extraordinarily complicated to compute, which is why the online tool is almost a necessity.
What is important is that both are legitimate ways of describing the data.
It should be kept in mind that population-growth estimates must consider births and deaths, not just births. That’s one reason why the Gregg et al. study was so important — it established, per BLM’s own documentation, a slightly-less than 20-percent birth-rate and a 50-percent foal mortality-rate. So, a wild-horse herd growth-rate of, for example, 65%, would have to mean a birth-rate that was much higher than 65% to offset foal deaths (50%) and adult deaths (5%).