Earlier this week, BLM released a fact sheet for public lands in Oregon and Washington during FY 2019.
Key management indicators can be computed for the wild horse and burro program in Oregon, using data on page 29 of the pdf. (There are no HMAs in Washington.)
Animals allowed by plan = 2,697 (some burros present but assumed to be 100% horses)
Authorized land = 2,698,902 acres
Current population = 5,878 (assumed to be 100% horses)
Required forage allocation = 2,697 × 12 = 32,364 AUMs per year
Current herd size = 5,878 ÷ 2,697 = 2.2X AML
Stocking rate allowed by plan = 2,697 ÷ 2,698,902 × 1,000 = 1 horse per thousand acres
What about livestock? Unfortunately, the data provided on page 30 don’t include the acreage designated for grazing and the average grazing season.
The number of cow/calf pairs can be estimated if you guess the grazing season but the stocking rate can’t be determined.
Authorized forage = 659,201 + 69,141 = 728,342 AUMs per year
Grazing season = 6 months (assumed)
Authorized herd size = 728,342 ÷ 6 = 121,390 cow/calf pairs
Stocking rate allowed by plan = ?
Livestock receive 22 times more forage than horses. But a more detailed comparison of management practices in Oregon is not possible, thanks to the missing numbers.
Western Horse Watchers Association 