A wild horse advocacy group has expressed dismay over a Nevada roundup, saying the number of horses that will be left on 600,000 acres will be below limits for healthy genetic variability.
On top of that, the mares returned to the wild will be treated with a long-term contraceptive.
Protect Mustangs’ criticism was aimed at the muster of about 120 wild horses from within the Reveille Allotment and Herd Management Area, about 50 miles east of Tonopah.
About 70 wild horses will be permanently removed, with 60 sent to holding facilities in Ridgecrest, California. About 10 will be offered for adoption after the roundup in Tonopah.
The remaining 50 wild horses will be released back into the area after mares have been treated with the long-term contraceptive, Porcine Zona Pellucidae (PZP-22).
The operation will leave a post-roundup population on the range of 98 wild horses.
This, the group says, will put the survivors at risk, noting that the minimum number for genetic variability is 150 animals.
“The Bureau of Land Management is wiping out America’s wild horses,” says Anne Novak, executive director of the group.
“We need to stop the roundups and protect our native wild horses.”
The roundup was scheduled to start on October 30, but its start was delayed to November 3.
The group has also voiced its concerns over the use of Porcine Zona Pellucidae, saying there was evidence that the drug sterilized wild horses after multiple use.
Protect Mustangs described the appropriate herd management level of 138 for the area as out of date and lacking in scientific merit.
“We must ensure native wild horses can survive upcoming environmental changes,” Novak says.
“The minimum population for a genetically variable herd is 150. Why are PZP advocates and the BLM allowing wild horse herds to fall below safe numbers?”
The group noted the findings of a National Academy of Sciences report released in June last year which found that the current practice of removing free-ranging horses from public lands promoted a high population growth rate.
“We are calling for an immediate freeze on roundups and removals for scientific reevaluation,” says Novak.
The BLM says the strategies proposed for the muster, including the use of the contraceptive, would allow for at least three years until the population neared the established appropriate management level, requiring another gather to be scheduled.
During the last Reveille gather in 2010, hair samples were collected from 51 wild horses and sent to Dr Gus Cothran, of Texas A&M University, for genetic analysis.
The results indicate genetic variants and genetic variation above the mean for other wild herds.
The closest similarity to domestic horses is with the light racing and riding breeds followed by Oriental and Arabian breeds.
There was also a cluster with a group of draft horse breeds.
According to Cothran’s report, the results indicated a herd with mixed origins with no clear indication of primary breed type.
During the current gather, hair samples will again be collected for further genetic analysis.