PZP: Where hope, science and mustangs meet

 

The longtime mustang advocate, TJ Holmes, and I head into southwestern Colorado’s Spring Creek Basin Herd Management Area, searching for mustangs. We do this regularly. TJ has documented these mustangs for eight years, working in partnership with the Bureau of Land Management. A big part of her work is administering PZP, the fertility-control vaccine (porcine zona pellucida), to the mares.

The air is heavy and smoke-filled from recent fires. Topping a rise, we see mustangs silhouetted against the hazy gray sky: three bands, each comprised of a stallion, his mares and grown offspring; and a group of young bachelor stallions. TJ recognizes each horse on sight and knows the roles each plays within the herd. I’m learning, and I see that something is missing — foals, the fillies and colts of springtime. 

Spring Creek Basin has a BLM-allotted carrying capacity of 35 to 65 adult horses, and is at about 60 right now. Yet there could be 20 foals on the ground, and there are only two, one before us napping with his mama in the heat, the second far across the range. More could come this year, but even with the expected three to five foals, this herd management area will not reach maximum capacity. 

That means no wild horses will be removed in 2016 or 2017, and no mustangs will head toward the overcrowded, short-term holding facility at East Cañon Correctional Complex near Cañon City. 

The last BLM roundup in Spring Creek Basin took place in 2011, when 82 mustangs resided in this herd management area, including 13 surviving foals (eight had died). The agency removed 40 horses, and for the next four years, TJ darted mares with PZP. Trained by Dr. Jay Kirkpatrick, senior scientist at the Science and Conservation Center in Billings, Montana, TJ used PZP on 10 mares the first two years, which dropped foal numbers to eight in 2013, and seven in 2014. The BLM then permitted TJ to dart more than 20 mares, and what we see before us — just one colt nuzzling his dozing dam — is the result of her successful PZP program.    

Wild horse in Wyoming, where PZP is also being tested.

PZP does not harm mare, fetus or nursing foal in any way, though a mare might buck or jump from the sting of a dart in her rump. Mares are not vaccinated every year; a BLM selection process based on genetics, age and herd health indicates which horses get the dart. PZP, which is reversible, causes eggs to reject sperm, though mares continue to cycle normally, with no disruption to herd dynamics or psychology. Stop the darting, and the mare can conceive again.

Still, some folks oppose PZP, seeing it as human meddling. But let’s face it: We’ve already meddled — digging ponds in desert soils to catch water, erecting fences to prevent mustangs from accessing natural water sources used for generations, ending “free roaming.” Solutions presented by the public are opposing and dramatic: Reinstate slaughter practices, or do nothing at all. Both are equally terminal ideas: death in the slaughterhouse, or death by starvation.

Introducing PZP into a herd area is the wisest action BLM can take for horses, habitat and the American public. With fewer horses born, fewer roundups happen, more years pass before removal is necessary, and fewer horses are taken to holding facilities. All this saves taxpayer dollars, and for the horses, fewer are traumatized and die unnecessary deaths. 

Taxpayers pay about $49,000 for each mustang removed from the range and not adopted. PZP costs about $27 per darted horse per year, and often the darters are volunteers like TJ, who works for mustangs, not wages. PZP has effectively slowed herd reproduction in Spring Creek Basin, as it has in Colorado’s Little Book Cliffs and Sand Wash Basin, and in additional herd management areas across the West. 

“The McCullough Peaks area in Wyoming reached zero-population growth in just three years,” Dr. Kirkpatrick told me, adding that the potential taxpayer savings was $7 million. “The Challis (Idaho) Herd Management Area is just getting started and estimates they have already saved more than $350,000.” Why, then, is the BLM not using PZP in every herd management area? That is the question the public needs to ask the BLM.

Horses, reintroduced to the Americas in 1493, are here, just like the rest of us. They have reoccupied this land for 500 years. We don’t have the wherewithal to control human population, homelessness and hunger, but with a $27 injection, we could make a huge difference in life on the range.

Kathryn Wilder is a contributor to Writers on the Range, the opinion service of High Country News. She has mustangs and cows and lives in Dolores and Disappointment Valley, Colorado.

High Country News Classifieds
  • INDIGENOUS AFFAIRS EDITOR - HIGH COUNTRY NEWS
    High Country News is hiring an Indigenous Affairs Editor to help guide the magazine's journalism and produce stories that are important to Indigenous communities and...
  • STAFF ATTORNEY
    Staff Attorney The role of the Staff Attorney is to bring litigation on behalf of Western Watersheds Project, and at times our allies, in the...
  • ASSISTANT VICE PRESIDENT FOR DIVERSITY AND INCLUSION
    Northern Michigan University seeks an outstanding leader to serve as its next Assistant Vice President for Diversity and Inclusion. With new NMU President Dr. Brock...
  • EXECUTIVE DIRECTOR
    The Clark Fork Coalition seeks an exceptional leader to serve as its Executive Director. This position provides strategic vision and operational management while leading a...
  • GOOD NEIGHBOR AGREEMENT MANAGER
    Help uphold a groundbreaking legal agreement between a powerful mining corporation and the local communities impacted by the platinum and palladium mine in their backyard....
  • EXECUTIVE DIRECTOR
    The Feather River Land Trust (FRLT) is seeking a strategic and dynamic leader to advance our mission to "conserve the lands and waters of the...
  • COLORADO DIRECTOR
    COLORADO DIRECTOR Western Watersheds Project seeks a Colorado Director to continue and expand WWP's campaign to protect and restore public lands and wildlife in Colorado,...
  • DIGITAL MEDIA SPECIALIST, THE NATURE CONSERVANCY: WYOMING, MONTANA AND UTAH
    Digital Media Specialist - WY, MT, UT OFFICE LOCATION Remote and hybrid options available. Preferred locations are MT, WY or UT, but applicants from anywhere...
  • GRANT WRITER (PART-TIME, FREELANCE CONTRACT) HIGH COUNTRY NEWS
    High Country News seeks an energetic, articulate and highly organized grant writer to support a growing foundations program. This position works closely with our Executive...
  • EXPERT COMPUTER & TECH HELP, PROVIDED REMOTELY
    From California, I provide expert tech help remotely to rural and urban clients. I charge only when I succeed. Available 7 days. Call for a...
  • ASSISTANT PROFESSOR OF HISTORY - INDIGENOUS HISTORIES OF THE NORTH AMERICAN WEST
    Whitman College seeks applicants for a tenure-track position in Indigenous Histories of the North American West, beginning August 2024, at the rank of Assistant Professor....
  • DAVE AND ME
    Dave and Me, by international racontuer and children's books author Rusty Austin, is a funny, profane and intense collection of short stories, essays, and poems...
  • CHIEF FINANCIAL OFFICER
    Rural Community Assistance Corporation is looking to hire a CFO. For more more information visit: https://www.rcac.org/careers/
  • EXECUTIVE DIRECTOR
    The Absaroka Beartooth Wilderness Foundation (ABWF) seeks a new Executive Director. Founded in 2008, the ABWF is a respected nonprofit whose mission is to support...
  • CANYONLANDS FIELD INSTITUTE
    Field seminars for adults in natural and human history of the northern Colorado Plateau, with lodge and base camp options. Small groups, guest experts.
  • COMING TO TUCSON?
    Popular vacation house, everything furnished. Two bedroom, one bath, large enclosed yards. Dog-friendly. Contact Lee at [email protected] or 520-791-9246.
  • ENVIRONMENTAL AND CONSTRUCTION GEOPHYSICS
    We characterize contaminated sites, identify buried drums, tanks, debris and also locate groundwater.
  • LUNATEC HYDRATION SPRAY BOTTLE
    A must for campers and outdoor enthusiasts. Cools, cleans and hydrates with mist, stream and shower patterns. Hundreds of uses.
  • LUNATEC ODOR-FREE DISHCLOTHS
    are a must try. They stay odor-free, dry fast, are durable and don't require machine washing. Try today.
  • WESTERN NATIVE SEED
    Native plant seeds for the Western US. Trees, shrubs, grasses, wildflowers and regional mixes. Call or email for free price list. 719-942-3935. [email protected] or visit...