A two-week public comment period has opened on a federal proposal to use a birth control drug to better limit the population of a wild horse herd in Tooele County.
In the past, the Bureau of Land Management has maintained a herd of 121-210 wild horses on the Onaqui Mountains by gathering the herd every three to four years and removing excess animals.
Removed horses are transported to a holding facility where they are sold to the public via a public auction.
According to a 35-page environmental assessment released last week by the BLM, the last round-up operation cost more than $83,000 to cull 34 horses from the herd.
The BLM has treated mares released after the last three round-ups with fertility control drugs, according to the environmental assessment, and has seen success in reducing the number of foals born after those operations.
Consequently, the BLM wants to expand the fertility control operation.
The proposal in the environmental assessment calls for BLM agents to administer an EPA-approved fertility control drug to select adult mares in the Onaqui herd through the use of dart guns. The BLM could use bait stations to lure mares into darting distance if necessary.
This management plan would be continued through 2020 and then reassessed to determine its success and impact on the herd.
The goal, according to the environmental assessment, is to bring the herd’s growth rate to seven percent and reduce the need for helicopter round-ups. To achieve that goal, each mare in the herd would be allowed to foal once and then would be treated with birth control on an annual basis for the remainder of her life.
The herd’s growth rate sits at 16-20 percent, according to the environmental assessment.
The environmental assessment does not propose any alternatives to the fertility treatment other than leaving the current management plan unchanged.
According to the environmental assessment, mares that receive fertility treatment can see improved health and may actually live longer than untreated mares. The fertility drug in question is also not known to pose a risk to unborn foals should the BLM accidentally treat a pregnant mare.
The BLM will accept written public comment on the proposal through March 6. Comments may be mailed to the Bureau of Land Management Salt Lake Field Office, 2370 S. 2300 West, Salt Lake City, UT 84119, care of Pam Schuller, or emailed to blm_ut_cedarmt_onaqui@blm.gov.
Comments should reference the “Onaqui Mountain Wild Horse Fertility Control Plan EA.”