On Oregon’s Hart Mountain National Antelope Refuge this year, the news was good.
Sage grouse counts were at an all-time high. Migratory birds absent from the refuge for decades have returned. This northwest corner of the Great Basin is seeing a resurgence of forbs, or flowering plants, which are essential food for lactating pronghorn antelope. Coyotes, which prey on pronghorn fawns, are down 40 percent since 1997.
Best of all, the survival rate for pronghorn fawns this year — one fawn for every two does — was the highest since the founding of the refuge in 1936. The 660 fawns that survived the spring fawning season bring the herd to 2,427 animals.
A decade after managers kicked cows off the land, and after several years of prescribed burning to reduce sagebrush density, the 275,000-acre refuge appears to be in the midst of a dramatic revival (HCN, 11/24/97: Restoring a refuge).
But now, refuge managers are inviting a blizzard of opposition by trying — not for the first time — to get authorization to shoot coyotes from airplanes.
Sometime this fall, refuge manager Mike Nunn will brief the Bush administration on a draft plan for managing the refuge’s pronghorn population. Although the plan has been in the works for five years, the agency has never released it to the public. It would allow shooting of coyotes if pronghorn fawn survival rates fall precipitously, as they did in the mid-1990s, says refuge biologist Mike Dunbar.
“It’s a tool to use when the fawn populations reach very low numbers,” he says.
“Hogwash,” says retired big game biologist Jim Yoakum, who has studied pronghorn on Hart Mountain for 49 years; he says healthy habitat, not predator control, is the key to maintaining pronghorn and other refuge wildlife.
Are coyotes to blame?
Hart Mountain can most likely trace its revival back to former refuge manager Barry Reiswig, who bucked strong opposition from Lake County, Ore., ranchers to document the damage caused by more than a century of cattle grazing. His 1994 management plan revealed a high desert refuge ravaged by cattle. Cows had trashed springs, trampled streambanks, contaminated creeks and destroyed aspen groves by eating the tender shoots.
Since the early 1990s, cows had been largely excluded from the refuge because of extreme drought conditions. In 1994, Reiswig made it official by evicting four longtime ranchers who held grazing permits on the refuge.
But the rebound wasn’t instantaneous. In 1995, the pronghorn fawn survival rate plummeted to a low of one fawn for every 100 does. The following year, Nunn became refuge manager when Reiswig was transferred to the National Elk Refuge outside Jackson, Wyo. (HCN, 6/23/03: State gets its way on a national refuge). Nunn blamed coyotes — which kill their share of pronghorn fawns during their first 10 days of life, before the fawns are able to outrun them — for the high mortality, and called for aerial shooting during pronghorn fawning season.
But a harsh winter and scarce forage were also factors that year. Refuge biologist Dan Alonzo told The Oregonian that the 1995 fawns “were born during a spring snowstorm, and most literally froze to the ground.” A never-released study by the Oregon Cooperative Fish and Wildlife Research Unit at Oregon State University concluded that the low fawn numbers were due to poor diet and brutal weather.
Nunn’s proposal to allow refuge managers to kill coyotes drew angry opposition from environmentalists, and he eventually dropped it. But after a two-year study concluded that coyotes were responsible for 75 percent of fawn mortality, he came back in late 1997 with a proposal to allow sport hunting of coyotes on the refuge. A coalition of environmental and wildlife groups filed suit in federal court, asking for a restraining order to stop the Fish and Wildlife Service from allowing the hunt.
“The Department of Justice lawyers said, ‘What the hell’s the matter with you?’ ” pronghorn biologist Yoakum recalls. The service paid the environmentalists’ legal fees.
Over the next few years, the antelope rebounded, reaching near record highs in 1999 and 2000 despite the absence of predator control. Yoakum credits several years of wet weather, the removal of livestock and feral horses, and the dramatic increase in forbs and other nutritious plants. A 1998 survey found that in some areas, forbs had increased by 300 percent in the absence of livestock.
No one is sure why coyote numbers have dropped. One theory, says Fish and Wildlife Service spokeswoman Susan Saul, is that prescribed fire, which has burned about 20 percent of the refuge since 1994, has led to a decline in voles, which live in old-growth sagebrush. Voles are an important food for coyotes.
Brooks Fahy, director of the Predator Defense Institute in Eugene, Ore., says the absence of predator control on a cow-free refuge has given wildlife biologists a rare chance to track natural fluctuations of pronghorn in a recovering grassland system. “This is the largest place in the West to have had cattle removed,” he says. The obvious lesson: “We shouldn’t be interfering with natural systems.”
A hidden agenda?
Despite the apparent success of Barry Reiswig’s 1994 refuge management plan, the Fish and Wildlife Service has moved ahead with its new pronghorn plan, which includes killing coyotes.
“The hidden agenda is that there are some active sportsmen in the refuge office,” says Yoakum. “They believe that the more animals there are, the more there will be to hunt.”
Refuge officials deny that a desire to increase hunting — presently the refuge issues 10 to 25 tags for bucks each fall — is driving the plan. “The comprehensive management plan was geared to habitat. It never defined the carrying capacity or optimum population of pronghorn,” says agency spokeswoman Saul. “What is the minimum number of pronghorn before we panic, the maximum number before we reach carrying capacity, the best population for public wildlife viewing?”
“Carrying capacity changes when vegetation changes,” retorts Yoakum. “It’s a living environment. Habitat determines the carrying capacity.” Although Yoakum has published 50 technical papers on pronghorn, and recently co-authored a wildlife biology textbook on pronghorn, he was not asked to help develop the plan.
The pronghorn plan is only the first round in what promises to be a renewed fight over management of the Hart Mountain refuge.
No cattle will be allowed on the refuge during the 15-year life of the 1994 management plan. But, refuge biologist Dunbar says, “In 2009, when the plan is up for review, everything will be on the table at that time, including restocking the refuge with cattle. Not everyone in the Fish and Wildlife Service is against cattle grazing. It depends on who is in power in Washington, D.C., and in the region.”
Dunbar agrees that recovery on the refuge has been stunning. “We can certainly say the habitat, especially the riparian habitat, has improved dramatically,” he says. “Whether we have enough information to say whether that’s due to no cattle grazing, I don’t know.”
“It looks better now than I’ve seen it in the past 50 years,” Yoakum says. “But it could be even better.”
The author writes from Portland, Oregon.
Hart Mountain National Antelope Refuge 541-947-3315
Predator Defense Institute 541-937-4261, www.predatordefense.org.