Thirty-seven years ago Congress passed the Free-Roaming Wild Horse and Burro Act with good intentions. When populations had tripled and it became apparent that these animals needed management, the Bureau of Land Management (BLM) created Adopt-A-Horse to handle the "surplus." The costly program worked for several years, but the BLM ran out of adopters. Next the agency started "warehousing" horses, and today we have 31,500 animals languishing in government corrals at a taxpayer cost of $23 million a year. A few years ago Congress passed (without public hearings) the Burns Amendment permitting older wild horses to be sent to slaughter. Public outrage ended that quickly, then when America's slaughterhouses were closed, that option was eliminated anyway. Most recently, the BLM proposed euthanizing wild horses as a means of population control.

BLM assateague

Fertility control has stabilized Assateague Island National Seashore populations. The stallion on the far left is flanked by mares in this 2007 photo. The light sorrel 10-year-old mare beside him received contraception at 2, 3, and 4 years of age, allowing her to mature before foaling. The bay mare beside the sorrel is 24 here. The other bay filly is 2 and just starting contraception.

Today, if one asks the BLM, a wild horse advocate, a rancher, a hunter, a range scientist, a taxpayer, or a member of Congress what the problem is, they get a variety of answers: too many horses for the space; competition with livestock and other wildlife for grass; high costs; "warehousing" is inhumane; not enough natural predators; horses are exotics and shouldn't live here; or the land belongs to the horses and not the domestic livestock. There are probably about a dozen other common answers.

While expensive, time-consuming population control attempts and emotional debates continued, horses on the range were, of course, reproducing! Despite this rather elementary notion, one rarely mentions reproduction as the real problem. Controlling populations with removals, adoptions, warehousing, slaughter, or euthanasia, while reproduction continues, is akin to treating brain cancer with aspirin. You can eliminate the pain for a time, but the cause persists and the outcome is predictable.

The National Park Service, however, recognized the true problem in the 1980s: reproduction. It approached herds on Assateague Island National Seashore (Md.), Cape Lookout National Seashores, the Rachel Carson National Estuarine Reserve, and Carrot Island (all in North Carolina), with fertility control. Today these areas do not face the crisis that BLM faces. They stabilized their herds--even reduced them in some cases--at a fraction of the cost. The process was very humane, and with modifications it can work in Western herds.

Twenty years ago the BLM was advised to treat every wild mare caught and released with a contraceptive vaccine. Many wild horse advocacy groups opposed contraception, not comprehending that wild horses, with no predators, cannot go unchecked. Bureaucrats didn't understand there is no quick fix. Even some animal protection groups opposed fertility control on grounds such as "violation of the reproductive rights." Perhaps the largest factor has been culture--one that manages wild horses like livestock, rather than treating them as a reintroduced native species. The real problem remains: reproduction. And in the meantime, range horses have continued--and will continue to--reproduce.

Jay F. Kirkpatrick, PhD, is director of The Science and Conservation Center in Billings, Mont. For 34 years he has researched nonlethal, humane fertility control methods for wild horses and other wildlife. He's best known for his work on the wild horses of Assateague (Md.), bison of Yellowstone National Park, and elephants in the Republic of South Africa.

Originally published in the October 2008 issue of The Horse: Your Guide To Equine Health Care.