Those evil horses.
“As [their] numbers have grown beyond the AML upper limit, livestock operators have experienced an increasing number of conflicts between wild horses and their permitted livestock use. Fence damage has increased as have maintenance costs. In some locations, wild horses have been very aggressive and kept livestock (and wildlife) from using the available water. In other locations, heavy-severe utilization by wild horses has prevented the [poor] operator[s] from making use of all or a part of their term permitted grazing use [on land set aside for the horses].”
Some ranchers have had to pay (OMG) market rates for rental pastures as a result of wild horse ‘overpopulation.’
The Devil’s Garden Plateau WHT covers 232,520 acres in northeastern California and has an AML of 335, for an aimed-at population density of 1.4 horses per thousand acres.
The Environmental Assessment for the WHT Management Plan indicates that 4,400 AUMs per year were allocated to these animals, a bit more than expected for 335 horses in a 12 month grazing season (335 × 12 = 4,020 AUMs per year).
The latter figure is used in the charts below.
The WHT intersects eight grazing allotments. See Tables 14, 15 and 16, beginning on page 79 in the EA, along with Figure 9 on page 80.
The EA provides the allotment size, authorized AUMs and the portion of the allotments within the WHT, but omits two of the grazing periods, citing them as variable. A term of six months was used for those calculations. Data for the East Grizzlie allotment were not provided because it is 98% outside the WHT.
The total permitted AUMs (26,880 AUMs per year) was used to scale the authorized AUMs to permitted AUMs but those figures were not used in the calculations.
Assuming that forage is uniformly distributed across the allotments, Carr contributes 1,701 AUMs to livestock inside the WHT because 40.7% of the land is inside the WHT.
The forage contribution of the other six allotments, added to Carr, yield 15,711 AUMs per year for domestic livestock inside the WHT.
Livestock can occupy an estimated 232,424 acres inside the WHT, computed in the same manner, which, allowing for rounding error, is taken to be all of it.
A six month grazing season yields 283 cow/calf pairs on Carr inside the WHT.
The other six allotments, combined with Carr, yield 2,856 cow/calf pairs on the WHT, for a weighted average grazing season of 5.5 months (15,711 ÷ 2,856) and average population density of 12.3 cow/calf pairs per thousand acres (2,856 ÷ 232,520 × 1,000).
These figures are presented in the following charts.
Land that can only support 1.4 horses per thousand acres can support eight times as many cow/calf pairs. The Pine Springs and Timbered Mountain allotments can support eleven times as many. A fine example of ‘thriving ecological balance.’
The current wild horse population at Devil’s Garden yields a pre-gather density of 7.7 animals per thousand acres, well within the range allowed for livestock. The roundup that starts in a few days will shift the numbers closer to those allowed by plan but will not achieve them.
The permitted AUMs for livestock across all of the allotments, inside and outside the WHT, yield an-aimed at density of 9.8 cow/calf pairs per thousand acres, using a grazing season of 5.5 months per year (22,608 ÷ 5.5 ÷ 419,249 × 1,000).
The WHB Act of 1971 was a dark stain on American history. Things will be so much better, at least for the ranchers, now that it’s gone.