Assateague Horse Survey: Any Day Now

NPS still hasn’t posted the results of the February census, at least not at their news site.

Last November, there were 22 stallions and 53 mares on the island (Maryland side).

If you don’t think that’s unusual, go get a pair of dice.  Set one of them aside.  Roll the remaining die 75 times, counting odd (or even) results.

Try coming up with (a) 22 or less such results or (b) 53 or more such results.

Feel free to leave your answers in the comments.

RELATED: Assateague Census in 2020.

Fertility Control Study Approved

BLM issued a Decision Record and Finding of No Significant Impact today for the testing of a contraceptive thought to be effective for three years.

The research will evaluate the efficacy of the vaccine against two oocyte growth factors, and if it can produce long-term infertility from a single dose.

The experiments will be performed on excess wild horses at the Northern Nevada Correctional Center in Carson City, NV.

If successful, the vaccine could help the agency achieve a thriving ecological balance on western rangelands, according to the news release.

RELATED: Comments Invited on Wild Horse Fertility Control Study.

Thriving Ecological Balance Rev 2

Comments Invited on EA for Black Mountain Gather Plan

BLM announced today the opening of a 30-day comment period on an Environmental Assessment for the Black Mountain Wild Burro Gather and Population Control Plan.

The HMA covers approximately one million acres in northwestern Arizona, including the old mining town of Oatman.  The AML is 478, for an aimed-at population density of 0.5 burros per thousand acres.  See Table 1 in the EA.

Black Mountain HMA Map-1

The current population is thought to be around 2,200.

The HMA intersects fourteen grazing allotments, although some of them are not active, according to Table 7.  Figure 15 in Appendix C indicates that roughly half of the HMA is subject to permitted livestock grazing, maybe a bit more.

The forage allowance for burros is half of that for horses.  If horses roamed the HMA, the plan would need to allocate 5,736 AUMs per year (478 × 12).  Given that the land was set aside for burros, the forage allocation would be 2,868 AUMs per year.

Comments can be submitted at the project documents page.  Substantive only, please.

What Is a Stocking Rate?

It’s a measure of population density, usually reported on these pages as animals per thousand acres.

Animal dispersion varies inversely with stocking rates—the lower the rate the greater the dispersion.

Stocking rates are also indicators of grazing intensity.  The higher the rate the greater the demand for forage.  Can the land keep up with animal appetites?

The management plan for the Pryor Mountains WHR allows 120 wild horses on 38,000 acres, for a stocking rate of 3.2 animals per thousand acres (120 ÷ 38,000 × 1,000).

Why not animals per acre?  Decimals.  The stocking rate expressed in those units would be 0.0032 animals per acre (120 ÷ 38,000).

The management plan for the Silver King HMA in eastern Nevada yields a stocking rate of 0.00022 animals per acre.

The scaling factor in the first calculation (1,000) shifts the decimal to make the result a little easier to read.

The Virginia Range in western Nevada has a stocking rate of approximately ten wild horses per thousand acres, while the average rate for lands managed by the BLM is one wild horse per thousand acres.

What might account for the difference?

Eagle Roundup Complete

BLM said today in a news release that the operation had concluded, with 1,716 excess horses captured and 47 returned to their home range.  The 24 deaths were not reported.

There has been much discussion on these pages about the effect on the horses but how many poor ranchers have been hurt by the mandatory AUM curtailment needed to achieve the Mojave-Southern Great Basin RAC standards for rangeland health?

There is no curtailment.

RELATED: Eagle Roundup Day 40.

Eagle Roundup Day 38

Cumulative totals through 02-22-20, per the BLM roundup page for the Eagle Complex:

  • 1,716 animals gathered
  • 23 deaths (1.3%)
  • 766 studs (44.8%)
  • 945 mares (55.2%)
  • 5 new foals (2019 foals counted as adults)

The proportions of mares and studs are still outside of statistical limits corresponding to n = 1,711 and p-bar = .50.  The number of mares removed from the area is assignably larger than the number of studs.  Why?

The gather target of 1,700 horses has been achieved.  Approximately 100 horses were to be returned but that hasn’t been reported yet.

Thriving Ecological Balance Rev 2

The horses are not starving when their population exceeds AML, they’re robbing too much forage from the most noble and deserving inhabitants of public-lands: Privately owned livestock.

RELATED: Eagle Roundup Day 36, Eagle Wild Horses Get Short End of Stick.

Eagle Roundup Day 36

Cumulative totals through 02-20-20, per the BLM roundup page for the Eagle Complex:

  • 1,656 animals gathered
  • 19 deaths (1.1%)
  • 741 studs (44.9%)
  • 910 mares (55.1%)
  • 5 new foals (2019 foals counted as adults)

A five year old stud was put down on day 36 due to injuries sustained while sorting.

The proportions of mares and studs are still outside of statistical limits corresponding to n = 1,651 and p-bar = .50.  The operation has removed a large number of mares from the complex, relative to studs.  The difference cannot be attributed to chance, but to one or more assignable causes.

The thriving ecological balance has been achieved, save for the removal of a few dozen more, followed by selective return.

Clearly, the WHB Act no longer affords the protections sought by Velma.

Eagle HMA Charts-1

RELATED: Eagle Roundup Day 34, Eagle Wild Horses Get Short End of Stick.