Wild horse sense

What could be more authentically Western than a herd of mustangs thundering across the range as windblown tumbleweeds roll across their path?

A lot of things, actually.

Both horses and tumbleweeds, or Russian thistle, were introduced from overseas, and both wreak environmental havoc. The thistle was imported accidentally on ships carrying grain; the horse’s history goes back hundreds of years to the first Spanish explorers.

At least 67,000 feral horses and burros now live under the supervision of the U.S. Bureau of Land Management in 10 Western states from California to Montana, 31,000 of them corralled at a cost of $40 million a year. The rest roam freely and, wildlife advocates complain, damage range land by cropping grass too low to the ground and trampling natural watering holes.

A 1971 law protected the horses’ ability to run free. As the heroes of such popular-culture favorites as “Spirit: Stallion of the Cimarron,” they are rightly called majestic, but they also constitute a thorny wildlife issue.

They arouse impassioned arguments about what’s natural in a world where nature has been thrown badly out of kilter. Some horse advocates contend that the equines should be considered legitimate wildlife, as opposed to a domesticated species that’s gone feral, because they have been here for hundreds of years; others contend they are native to the region because horses originated in North America, with some migrating over the Bering land bridge to Asia. The North American horse became extinct about 10,000 years ago when the other large mammals of the Ice Age, such as the woolly mammoth, also died out. Their Asian cousins survived and eventually spread west, becoming the domesticated Iberian horses that were brought to North America by explorers starting in the 15th century, completing an evolutionary trip around the world.

The trouble is that during the 10,000 years without horses, North America evolved without them, and they no longer have a place in the natural environment. Arguing that mustangs have a right to open land because their remote ancestors lived here is like saying elephants should roam California because woolly mammoths used to frequent the La Brea tar pits.

Because the horses overpopulate their range, the BLM rounds them up by the thousands. The intent is to have them adopted at $125 a horse. But few people have the expertise and resources to successfully adopt a wild horse, and in stressful financial times, equestrians are abandoning their steeds, not taking on new ones. The BLM says there are 9,000 more horses than their range can sustain and that the cost of corralling and feeding them already exceeds the budget. The agency wants to cull the herds.

It’s too early to talk about killing horses, though the outrage from horse advocates at the very idea seems outsized in light of the number of dogs and cats euthanized each year and the number of deer culled through hunting. But a federal bill designed to protect the horses from euthanasia could make things worse.

The legislation, which passed the House this month but might face a rougher time in the Senate, would set goals, without imposing mandates, for increasing the horses’ range by 20 million acres, at a cost estimated by the Congressional Budget Office of $500 million. The bill also would prohibit euthanasia of all but terminally ill horses and limit the time that newly corralled horses spend in captivity to six months.

Opening up millions of additional acres to horses isn’t a good idea. Wildlife managers in Nevada -- which along with Wyoming holds the most wild horses -- already complain about the wild herds’ effect on the land and on other species, especially antelope and bighorn sheep. Providing more land would worsen the damage and promote population growth, exacerbating the predicament for both horses and native species.

At the same time, releasing horses to inadequate range simply because they’ve been penned for six months is downright cruel. In 2007, more than 200 horses died in Nevada because of drought and low grass supplies. Horse advocates point out that privately owned cattle, which are allowed to range on BLM land in much greater numbers, likely cause more damage than horses. They have a point, and the public land leases for cattle grazing should be revisited as well. But cattle are controlled rather than free-roaming. They can be provided with water troughs and moved seasonally to prevent land damage.

A better solution for the horses would be to create vast but contained wildlife refuges with adequate grassland. Horses have largely been relegated to poorer quality lands, while prime grasslands have been given over to cattle-grazing leases. This would make it easier to monitor the herds and administer birth control. In fact, equine contraception, which is included in the House bill, might offer the best hope of humanely keeping the animals alive while protecting wilderness.

The Humane Society of the United States has been working on an injectable contraceptive for mares that it says is effective for several years before a booster is needed. It should be allowed to demonstrate whether this works and given adequate federal funding to do so. The BLM also should be given the go-ahead to geld stallions, which could prove more effective than injections.

Animal advocates contend that gelding would interfere with the natural social structure of the horses, but it’s time for them to figure out that there is little truly natural about the modern mustang. The dire wolves and saber-toothed cats that kept their prehistoric ancestors’ numbers in check are long gone. Mustangs compete with imperiled native species and destroy sensitive habitat, and as a result are rounded up into pens that are anything but natural. Without birth control and a more contained environment, the sad possibility of euthanasia will have to be weighed against even sadder possibilities for this Western icon.