l crouch really low; sometimes I crawl on the ground.”
So darting at Cedars is impossible. Administering PZP-22 there requires rounding up the horses and hand-injecting the drug. Helicopter gathers in 2008 and 2012 allowed Grams to treat 75 percent of the mares.
Sand Wash Basin is a much easier place to contracept horses. To reach the herd all you need to do is drive up along a road, park your truck and take a hike. This means many local horse lovers know the herd and tourists visit, so the animals are used to people. Even with wide open vistas and little opportunity to hide as she stalks the herd, Grams says she can get within 10 yards.
On a typical day at Sand Wash, Grams finds the horses in a band grazing, heads down. Once in a while, one looks up. The lead mare and the stallion are watching. Gradually, if a human approaches, the herd, taking a few steps here, a few there, will move off. So Grams walks nonchalantly toward the band, acting as though she really isn’t headed that way at all. She passes them and waits with no movement, like she is a tree rather than a person. Patiently, she sticks with the band, dogging the group of horses the way “bachelor” stallions do when they are hoping to steal a mare from a stallion’s harem. Sometimes, she hides behind brush or rocks. After a long time, she can get within 40 or 50 yards, close enough to take a shot—but only if the wind isn’t blowing.
Grams targets subordinate mares first, waiting to dart the lead mare last because that horse will alert the others. As the horse she’s targeting moves within range, she creeps closer, stops, then creeps closer again, while the horses in turn adjust their positions, ambling always a little farther out of reach. Finally, she takes her shot. The dart hits the mare in the hindquarters, delivering the vaccine. The mare’s only reaction is to kick up her legs. But all at once, the other horses move subtly, putting their bodies between Grams and the lead mare or another horse she is targeting. Usually, she does not get another clear shot.
Last fall, Josh Irving, the HSUS field technician assigned to Sand Wash, was able to dart 69 percent of targeted mares there, with help from Fox and Grams. That’s within the range The HSUS hoped to treat. It’s a slow process, not half as dramatic as a gather and removal, with results a year or more off, but Irving is convinced it’s the answer for Sand Wash. “You do have to put in the time and you have to be patient, but at day’s end, it’s cheaper and it works.”
Fox, Sand Wash’s wild horse and burro specialist, hopes he’s right. More than 400 horses live in the basin, an area the BLM estimates can support at most 362. With the herd increasing in size by 20 to 25 percent annually, it could triple within six years. Already, some parts of the area have little vegetation and others have lost their native grasses to cheatgrass, which has a lower percentage of digestible protein and a shorter growing season. “We’re looking at anything to slow down recruitment,” Fox says.
The BLM is investing $2.8 million into researching contraception and sterilization methods. What the agency would ideally like to find, Guilfoyle says, is a contraceptive that can be administered just once every five years—otherwise she can’t see contraception being used in the majority of the 179 areas BLM manages. Studies of a PZP vaccine that could be administered once every three to four years are under way, says John Turner of Ohio’s University of Toledo, who is doing the research for the BLM. The agency also plans to use private money to establish a prize challenge encouraging research into wild horse contraceptives, including easier methods of administering the drugs than darting or gathering.
The BLM, though, needn’t wait for further research to use PZP-22, the best contraception that exists, says Boyles Griffin. “We don’t have a perfect tool,” she says. “But we have a tool that works really well.”
Turner agrees. If the agency had begun using PZP and PZP-22 on a large scale 15 years ago, the current crises of too many horses in management an