BLM considers plan to intensify fertility program for wild horses

The BLM is considering a modification to the current fertility plan it uses to control the number of horses on the Pryor Mountain Wild Horse Range. The new plan will significantly increase the number of mares darted with the fertility drug PZP.

Photographer Kassi Renner captures a great image during a rare sighting of the famous stallion Cloud as he takes a flying leap across some rocks on the Pryor Mountain Wild Horse Range. Courtesy photo
Photographer Kassi Renner captures a great image during a rare sighting of the famous stallion Cloud as he takes a flying leap across some rocks on the Pryor Mountain Wild Horse Range.
Courtesy photo

According to language in a scoping report released in the spring of 2013, the goal of the new plan is to treat “nearly all of the mares” on the range with the fertility drug, theoretically rendering them infertile for a period of time. Currently a group of mares in the 5-10-year-old range are not treated with the drug and remain able to reproduce on the range.

Since the 31,000-acre range is fenced, the number of horses must be kept in check to prevent a negative impact on the land and to preserve the limited resources the horses themselves require for their own survival. The BLM plan is to maintain an appropriate management level (AML) of 90-120 wild horses on the range, by means of a carefully planned fertility program.

The original fertility plan, which was implemented in May of 2009, calls for treating a significant number of mares using a system of darting the horses with the drug PZP, which, in theory, renders the mares infertile for one breeding period (approximately one year).

The mares must first be primed with one dose and then darted with second dose before they are rendered infertile. In the opinion of some wild horse advocates, like Matthew Dillon of the Pryor Mountain Wild Mustang Center (PMWMC) in Lovell, not darting the mares in the 5-10-year-old cohort preserves the long-range survival of the herd by preserving certain historic blood lines and maintaining genetic diversity of the herd. Dillon has worked very closely with the BLM in recent years to share his extensive knowledge about the various bloodlines and has made many recommendations to the BLM (which they have adopted) regarding which horses can be safely removed from the range to preserve those bloodlines. He noted that the use of PZP is not a foolproof system and has in a few instances rendered mares completely infertile after just one dose and in other cases not rendered certain mares infertile at all. Mares that have received repeated doses have sometimes lost their ability to reproduce altogether.

“One of the reasons we don’t like the modified program is that we know anything can happen out there on the range,” said Dillon. “Right now we are not having a lot of foal deaths, but that can change. One of the reasons we like the conservative approach of the current program is that we always have that core group of mares that we can count on to reproduce if repopulating becomes necessary due to some natural cause.”

Dillon said he prefers to see the BLM stick to the more conservative approach by leaving certain mares out of the program and doing smaller gathers of 10 or fewer horses to manage the herd.

The PMWMC went on record with the BLM this week in a letter signed by all of its board members expressing their opposition to the plan, stating that “the long-term sustainability of the herd should be the primary management goal…with maintaining primary bloodlines as an objective.”

“I think the plan puts the needs of the horses being removed above the needs of the horses remaining on the range,” said PMWMC board member Nancy Cerroni.

Cerroni acknowledged that the typical 50 horses removed in a gather can be difficult to adopt out, but she said she believes that finding more adoptive homes is the answer, not limiting the breeding population.

“I really don’t think we’ve tapped into all of the avenues for adopting in today’s horse world,” she said. “I think if the problem is getting the horses adopted out that are removed from the range, we should work on that problem as opposed to creating a new problem with a more aggressive fertility program.”

The existing five-year plan, which is scheduled to end in 2015 has significantly reduced the number of horses on the range, but it has not eliminated the need for gathers and the subsequent need to adopt out the horses removed from the range. Some advocates like Ginger Kathrens of the Cloud Foundation, a wild horse advocacy group based in Colorado, say the adoption process has become problematic in that it is becoming more and more difficult to find homes for the horses that are taken off the range. Kathrens, who in the past has been adamantly opposed to the use of PZP on the mares, went so far as to recommend an increase in the number of mares that are darted with PZP in order to reduce the need for removal of horses from the range.

“I am concerned about how difficult it was to get the last group of horses adopted out that were removed from the range during the most recent gather in 2012,” said Kathrens. “In 2009, I saw about 100 people at the auction looking to adopt horses. This year it was more like 40 and many of those were from the same family. There were many instances where horses were not being bid on at all, and some were going for as little as $125. I had to get on the phone and call everyone I knew to get the horses adopted out this time. I just don’t know that I can do that again. That’s why I suggested a more aggressive treatment program using PZP. It’s the only alternative I see right now that is in the best interest of the horses.”

Kathrens said her preference would be to allow nature to take its course, with herd reduction occurring through predation by mountain lions. She noted that more frequent hunting of mountain lions in recent years has significantly impacted that natural cycle, causing more foals to survive than would normally occur.

“My preference would be to see the fence come down, a bigger population of active predators like mountain lions controlling the size of the herd and a return to survival of the fittest,” said Kathrens. “Unfortunately, that’s not realistic right now.”

She noted that, ironically, she is involved in a lawsuit against the BLM regarding the fence but feels she is forced to actually collaborate with them on the issue of the fertility program in the best interest of the horses.

“I think it’s best for horses to live and die on the range,” said Kathrens. “Even in cases where that horse, as a foal, may only live a few days. It is, in my opinion, better for that horse to have lived and died on the range.”

Kathrens sent a letter to the BLM on behalf of the Cloud Foundation in the spring stating, “The Cloud Foundation (TCF) recommends the more effective use of the well-vetted, remotely delivered, reversible one-year vaccine, PZP (Porcine Zona Pellucida) for mares in the Pryor Mountain Wild Horse Range (PMWHR), with the goal of eliminating removals or limiting future removals to 10 young horses or fewer every four or five years.”

The BLM incorporated the Cloud Foundation’s suggestion to increase utilization of the PZP program in their new plan, which calls for modifying the current fertility control prescription to apply fertility control to “nearly every mare on the PMWHR through 2015 in order to help maintain the appropriate management level of 90-120 wild horses and to reduce the need for a large scale gather.

Kathrens said the goal of TCF is to see mortality and reproduction of the herd roughly equal over time. She referred to this as a type of “on the range management,” that TCF advocates for all the herds, not just the Pryor Mountain herd.

“We advocate for the protection of predators–as a form of natural management,” she explained. “From 2001 to 2005, this objective was met on the Pryors, until BLM managers encouraged the hunting of mountain lions and the natural balance was destroyed.”

The modified plan is under a 30-day public review and comment that will end on Sept. 6, 2013. If adopted, the plan will immediately go into effect in September of 2013.

Kristen Lenhardt of the BLM said that the public comment gathering by the BLM during the review period is taken very seriously and is oftentimes incorporated into the final decision made by the BLM.

“Now is a critical time frame for the public to comment,” said Lenhardt. “We encourage the public to submit their comments and suggestions so we can take them into consideration when making this important decision.”

The documents are available for public review on the Billings field office of the BLM website: Instructions for submitting comments are also available on that website.

by Patti Carpenter