Category: Range

On the range

Black Mountain Burros Get Short End of Stick

Refer to Section 1.1 of the EA for the Wild Burro Gather Plan.  Forage in the HMA has been degraded and two grazing allotments don’t meet standards for rangeland health.

The current number of burros exceeds the limit that achieves and maintains a thriving ecological balance vis-à-vis the multiple use and sustained yield mandates for the area.

OK, but what do the numbers tell you about the HMA, the way it’s being managed?

The management plan allows 478 wild burros on the HMA, which contains one million acres.  The aimed-at stocking rate is therefore 0.48 burros per thousand acres.

The forage allocation for the burros would be 2,868 AUMs per year, given that they’re on the range twelve months per year (478 × 12 ÷ 2).

The forage demand of burros is half of that for horses, so their impact on the land cannot be compared directly to livestock.  The forage requirements of horses are said to be equivalent to those of cow/calf pairs, so the comparison will be done on that basis.

The AUM budget won’t change but the AML and stocking rate will.  If the HMA was managed for wild horses, the AML would be 239 and the stocking rate allowed by plan would be 0.24 per thousand acres.

Table 7 in the EA provides data for livestock grazing on the HMA.  A BLM rep contacted by WHW confirmed that the grazing season is 12 months per year.

Six of the sixteen allotments are designated for intermittent use, when forage and other conditions are favorable.  They have been omitted from the calculations.

Note that the stocking rates for livestock (cow/calf densities) are considerably higher than the 0.24 allowed by plan for horses (who are proxy for the burros in this analysis).

Black Mountain Calcs-1

The land grazed continually corresponds to about 22% of the HMA.  The parcels grazed intermittently would bring the total to approximately 50%, as estimated in the original post (linked below).

The total estimated forage available to livestock inside the HMA is 7,333 AUMs per year, computed as the sum of the permitted AUMs for each allotment times the portion of each allotment inside the HMA.  For example, in Big Ranch A, 5,397 × .312 = 1684.

The estimated number of cow/calf pairs inside the HMA is 611, with an average grazing season of 12 months per year (7,333 ÷ 611).

The stocking rate for cow/calf pairs is 2.77 per thousand acres (611 ÷ 220,891 × 1,000).

Horses (burros, actually) receive 28% of the forage, compared to 72% for livestock.

These figures are compared in the following charts.

Black Mountain Charts-1

These indicators tell you that the HMA is managed primarily for livestock.

The thriving ecological balance—to be achieved by the roundup and maintained by one or more population controls—is not a balance at all.

The forage assigned to livestock would support an additional 1,222 burros (7,333 ÷ 12 × 2), for a new AML of 1,700 (478 + 1,222).

If the grazing allotments are fenced and livestock are present twelve months per year, can the burros access the resources on those parcels?

Has the most productive land in the HMA been given to the ranchers?

Would the loss of 72% of their forage explain their movement off the HMA?

If livestock are confined to the allotments by the same fences that keep the burros (and other wildlife) out, why attribute the substandard conditions to them?

Next time you see management actions justified by ‘multiple use’ and ‘sustained yield,’ know that they are code words for diverting most of the resources to privately owned cattle and sheep, minimizing the number of wild horses and burros, while giving the impression that the area is managed according to paragraph 1332(c) of the statute.

The term ‘Potemkin Village‘ comes to mind.

RELATED: Comments Invited on EA for Black Mountain Gather Plan.

PSA 12-07-19

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.