The Bureau of Land Management plans to surgically sterilize wild mares and geld stallions captured during a roundup scheduled for November, then release them back onto the Confusion Herd Management Area, located about 90 miles northwest of Delta, Utah.
BLM plans to capture 560 wild horses. Of those, 500 will be permanently removed from the range, while others among the remaining 60 will be sterilized eventually released.
There are currently an estimated 661 wild horses on the Confusion Herd Management Area. According to BLM, once it reaches the low end of the 70-115 horse “Appropriate Management Level” set by the agency, no more than 10 geldings will be released onto the range and a minimum of 50% of the mares on the range must remain fertile. That means that about 16 or 17 mares would be sterilized, BLM said.
Ovariectomy via colpotomy is a rare procedure which removes the ovaries by crushing and pulling them out with a looped-chain medical instrument called an ecraseur. This procedure opens the mares up to: serious risk from infection; evisceration (should intestines come through the incision); and hemorrhaging. There is a high frequency of post-operative complications affiliated with ovariectomy via colpotomy, some of which can be life-threatening. Most domestic horses upon which this surgery is performed are hospitalized for 3 to 7 days and quite carefully monitored post-operatively for signs of hemorrhage.
While less dangerous, gelding stallions is nonetheless problematic. Gelding a colt that is too young can stunt its growth, while gelding older stallions risks increased bleeding and requires more recovery time. Moreover, it would require gelding all the stallions in a herd, as even a small number of intact stallions can impregnate all the mares in a herd. Surgical sterilization also changes the behavior of wild, free-roaming stallions. “A potential disadvantage of both surgical and chemical castration is loss of testosterone and consequent reduction in or complete loss of male-type behaviors necessary for maintenance of social organization, band integrity, and expression of a natural behavior repertoire,” concluded the National Resource Council in a 2013 report.
As RTF noted in its public comments to BLM’s Environmental Assessment for this planned roundup:
“There are no substantive studies to evaluate
“Surgical spays polarize stakeholders and lead to litigation. The BLM has an opportunity here to set this management strategy aside – because it can: because other forms of proven, safe, humane reproductive growth suppression exist and their use is generally supported by the public (PZP, PZP-22, GonaCon). [Note: BLM supports the use of PZP and PZP-22. GonaCon interrupts the hormone cascade, GonaCon may cause other behavioral changes that would affect herd dynamics. As such, RTF would like to see more studies to ensure that GonaCon meets the parameters of ethical and thoughtful wildlife fertility control.]
“Every time the BLM has proposed to research surgical spays the projects have been delayed due to litigation. One can assume that the same would happen if BLM pursued surgical spays in this context…
“We do not advise gelding as a population management tool since there are effective and well-studied, safe, effective, and humane and reversible population growth suppression alternatives and there are not sufficient studies to understand the behavioral effects of gelding some proportion of a population. Modeling for population effects is a guess, at best.”
BLM blames wild horses for competing heavily with other wildlife, including mule deer and pronghorn, for forage and water, on the Confusion HMA, “degrading rangeland health,” and “trampling…riparian areas.”
The Confusion HMA measures 293,665 acres of public and other lands. The “Appropriate Management Level” of 70-115 means a goal of as few as one horse for every 4,195 acres.
By comparison, 11 livestock operators grazing animals on five allotments overlapping the Confusion HMA are authorized to use 25,312 Animal Unit Months of forage annually (One AUM is the amount of forage needed to sustain one cow, five sheep or five goats per month).
In 2018, BLM reduced livestock AUMs on the Thousand Peaks Allotment, which largely overlaps the Confusion HMA, from 18,597 to 12,289, a 34% reduction based on a December 2016 assessment of the allotment, according to planning documents.
Wild horses removed from the range will be prepared for the BLM adoption and sale program.