http://trib.com/news/state-and-regional/article_01e28808-7d9f-518e-8436-83f6f2d58137.html?mode=story
By Martin Kidston
Billings Gazette
CODY — The Bureau of Land Management will begin darting wild mares in the McCullough Peaks with a contraceptive later this month in a move that the agency says will cost less than past roundups and help stabilize the herd’s population.
Officials with the BLM’s Cody Field Office will dart mares over the age of 1 with the fertility control drug porcine zona pellucida, or PZP, in hopes of establishing a viable population of 70 to 140 wild hores.
Tricia Hatle, the BLM’s wild horse specialist in Cody, said Monday that two trained wildlife darters will administer the vaccine using capture guns. The effort is expected to run through 2015.
“One person will dart the mare, and the other person will be the observer,” she said. “We’ll recover the dart so we know if the vaccine was injected. It’s administered in the hip, in the muscle. It’s about 1 cc, a very small amount of liquid.”
Hatle said targeted mares will receive .5 cc of PZP. The drug would be mixed with .5 cc of an emulsifier known as Freund’s Modified Adjuvant.
Hatle said the vaccine works by blocking sperm from penetrating the mare’s egg. The PZP will be shipped to Cody by the Science and Conservation Center at ZooMontana in Billings, Mont.
In past years, Hatle said, management of wild horses in the McCullough Peaks has largely relied upon gathers and removals to control the population.
But those efforts have been costly. In 2004, when 362 horses were removed from the McCullough Peaks management area, the cost reached $135,000. In 2009, when 94 horses were removed, the cost exceeded $102,000.
“Our goal is to keep the herd at 140 or below,” Hatle said. “As of February, we were at 124 adults, and we’ve had one foal born so far.”
Hatle said the wild horses in the McCullough Peaks generally live 25 to 30 years — a little longer than their wild counterparts roaming Montana’s Pryor Mountains.
As the mares mature, she said, they’ll be permitted to foal. The newborns will ultimately replace older horses that die off.
“What you want to balance out is having foals born in proportion to horses that die of old age, so your population stays at a balanced level,” Hatle said. “You do this by allowing the mares to foal between 3 and 7 years of age.”
Mares that reach the foaling age will no longer be treated with PZP, she said. It may take one or two years after vaccination before the drug wears off.
“This allows the mare to mature fully before they foal,” Hatle said. “It’s easier to let them have a foal at 3 to 6 years. Right now, I have mares foaling at two years.”
Sarah Beckwith, public affairs officer for the BLM’s Wind River/Bighorn Basin District, said the new contraceptive program will cost less than past roundups.
She said Friends of A Legacy-McCullough Peaks Mustangs will pay for the PZP and assist in the field. The only cost associated with the program, she said, is Hatle’s time administering the vaccine.
“FOAL will be donating its time and paying for the PZP, and (Hatle) is doing this within her workday, so there’s no extra cost,” Beckwith said. “It’ll be much cheaper than the roundups.”
Members of FOAL couldn’t be reached Monday for comment, but Beckwith lauded the group for its efforts in addressing the herd’s long-term care.
“It’s such a helpful and wonderful partnership we have there with them,” Beckwith said. “Their goal is the same as ours — to reduce the need of those roundups. With this program, that’s what we’re aiming to do.
Contact Martin Kidston at 307-527-7250 or mkidston@billingsgazette.com
Spring Creek Basin Mustangs 
This is fantastic news.
Yes!!
TJ, this sounds very good, especially allowing the fillies to grow up before they get pregnant. I have a few questions you or others may or may not be able to answer.
I couldn’t find McCullough Peaks on the 2011 Gather Schedule. Does this mean the horses won’t be rounded up, and instead mares will be selectively darted on the HMA, and no horses will be removed? Will the herd ratio still be skewed, which Carol Walker felt caused so much disruption after the last gather? The article and BLM Press release say PZP, so assume it will be the annual application. Is this true, or will they use PZP-22 or some other drug?
This isn’t criticism of an obviously well thought out, cooperative plan. I just want to understand a bit more about the process.
Fantastic news, indeed!
I’ll answer what I can. There won’t be a roundup there as far as I know (one of the benefits of native PZP darting!) – they’ll be doing the remote darting and yes, using native/annual PZP. One of the people in my training was from FOAL. I don’t know about the gender skewing there – which I assume happened at the roundup (with horses removed/released). They said they did or wanted to do that here at our last roundup, though they released five mares, a filly and four stallions … but the overall makeup ended up being many more stallions to mares anyway. The issue has been skirted here for the upcoming roundup. I think we have quite a bit of “dysfunction” here, too, but there will always be bachelors … it’s hard to tell what’s caused by gender skewing, small herd size, etc. What’s normal? Whatever they make it. The hand of man has to be involved, as much as we’d wish it otherwise – the reality is in fences and finite spaces (though we have much less of it than McCullough Peaks!).
The tide definitely seems to be turning in favor of PZP where possible. We have to go through the (government) process. With both Pryor Mountain and McCullough Peaks approving the annual darting by BLM/volunteers, it makes me even more hopeful that it will happen here – where I’ve done the same groundwork to prepare for it being a very successful program … patting myself on the back with full acknowledgment of these folks – Little Book Cliffs, Pryor Mountain, McCullough Peaks – who have set the precedent! 🙂
This seems to be a better solution than the round ups. At least we won’t have horses terrified and killed. I hope it works out.
Hopefully very soon I’ll be calling on readers of the blog (and others) to submit comments to the Dolores Public Lands Office that we want an annual PZP program implemented in Spring Creek Basin for the express purpose of reducing the need for roundups and wild horses in short- OR long-term holding. That scoping letter should be out very soon, and I will post about it then ASAP.
This is GREAT news!! We both wrote in support of the McCullough Peaks Fertility Plan and will absolutely do so for Spring Creek! Change takes time, but it will come, we just have to continue to wait and believe. It’s worth noting that any such plan would be impossible for *our* horses in S.C. if it weren’t for you, TJ – THANKS! 🙂
While I can take some credit (and am very appreciative!), this is another great opportunity to remind everyone that LOTS of credit and MUCH appreciation has to go to ALL the people who have worked for the Spring Creek Basin mustangs for longer than I’ve even known they’ve existed – and that I do what I do with their amazing support. The Colorado chapter of the National Mustang Association was started here close to 15 years ago (at the encouragement of the BLM herd area manager at the time!), and Pat and Frank Amthor of the Four Corners Back Country Horsemen started the annual wild horse count about 12 years ago. Mesa Verde Back Country Horsemen and San Juan Mountains Association also are involved in advocating on behalf of the horses. It takes a village, as they say, and it’s no different in this case. And when it comes to getting public comments about our hoped-for fertility control program, it’s going to take an even bigger village – and I hope all of YOU will be part of it!