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Who speaks for the sheep?

Desert bighorns are caught between waterholes and wilderness

 

Refuge manager Don Tiller wishes sheep could talk. On southern Arizona's Cabeza Prieta National Wildlife Refuge, their words would resolve a decade-old dilemma.

In 1939, Cabeza Prieta was established, in part to help recover desert bighorn sheep populations in their historic range. At the time, managers and biologists assumed artificial waterholes would help sheep survive in the stark, dry landscape of saguaro cacti and creosote bush. Since 1948, 23 waterholes have been built, monitored and maintained on the refuge.

"Almost every one is different," Tiller says. Some are simple retaining walls constructed alongside a natural flow of water. Others have concrete or metal roofs to prevent evaporation, and still others are holes blasted out of rock. These waterholes either blend into the reddish-tan sand or stick out like sore thumbs against the rugged mountain ranges, the tallest at 3,200 feet.

But a 1990 law that set aside wilderness areas across the state has forced the U.S. Fish and Wildlife Service to question whether these water developments are critical to bighorn sheep survival. The Arizona Desert Wilderness Act designated 93 percent of the 860,010-acre refuge as wilderness. Now, new roads, motorized vehicles and construction are prohibited unless needed to preserve wilderness resources.

As Cabeza Prieta managers begin to develop a long-awaited management plan, Tiller and his staff find themselves caught in a battle between wildlife advocates and wilderness advocates. It's a lose-lose situation for Cabeza Prieta managers: they catch hell from environmentalists for hauling water by motorized vehicles in wilderness, and from sportsmens' groups and the state wildlife agency for not doing enough to manage sheep populations.

"Just white skeletons"

Wildlife biologist John Hervert with the Arizona Game and Fish Department says it's obvious that Arizona bighorn sheep need waterholes. For one thing, their food supply has changed. Cattle grazing prior to the 1970s left inedible creosote bush in place of the grasses so delectable - and full of essential moisture - to bighorns. For another, sheep must deal with the presence of humans in their habitat. Illegal immigrants traveling across the refuge startle the sheep and force them into less than ideal areas. Hervert says these pressures, combined with extreme thirst during dry stretches, can be fatal.

Hervert, who flies over the refuge every three years to estimate the bighorn population, says the Granite Mountain range in the Cabeza Prieta used to have a reliable man-made waterhole that helped support a sub-population of 50 sheep. But when the waterhole dried up, more than 40 bighorns died.

"When I flew over that area, I found dead bighorns all over the mountain," Hervert says. "Just white skeletons."

Though not everyone agrees that the sheep died of thirst, Cabeza Prieta's managers say they need to play it safe by hauling water during the hottest months. "Until it is more clearly shown that (sheep) don't need the water, we want to haul water," says refuge biologist John Morgart.

"Is it absolutely essential that they get free water to survive?" asks refuge manager Tiller. "The answer is probably 'no,' if the habitat is good. But it's not all good."

Although managers have hauled water into the wilderness area seven times so far this year, the Arizona Desert Bighorn Sheep Society worries that they are not checking waterholes as often as they should because they want to limit motorized use in wilderness.

"(Managers) can't go out and determine if there is an emergency," says Brian Dolan of the Sheep Society, a nonprofit conservation organization that has helped build more than 194 waterholes across the state. "In my opinion, there should never be an emergency. The waterholes should be routinely checked by the Fish and Wildlife Service, and if they are silted in, the silt should be removed, and if they are low, they should fill them up."

The Sheep Society cites a 100-animal decline in the bighorn sheep population since 1993 as a direct result of the wilderness rules.

In an eight-page letter submitted to the service in April, the Sheep Society and the Wildlife Conservation Fund of America urged the agency to reestablish "long-standing management practices' on the Cabeza Prieta and nearby Kofa National Wildlife Refuge. Their letter claimed that Congress never intended the wilderness designation to eliminate proactive wildlife management.

Wilderness is for wildlife

Jim Waltman of The Wilderness Society couldn't disagree more. According to him, the 1990 Arizona wilderness bill made no exceptions for vehicles in Cabeza Prieta. Wilderness designation is an additional purpose for the refuge, he says, not an underlying purpose. "Adding wilderness on top of the purpose of the refuge is to conserve natural wildlife populations and habitat by preserving wilderness," Waltman says.

"Wilderness areas are supposed to be free from motorized vehicles and mechanized equipment," he says. "They are supposed to be places where we say "no" to those kinds of things."

Motorized vehicles also cause basic biological problems by spreading weeds, compacting the soil and changing the way water flows along the ground, Waltman says. By driving in the wilderness, he says, agency officials invite other people - hunters, state agency officials, border patrol officers and visitors - to ignore the wilderness signs and follow the well-worn roads.

Even top-level Fish and Wildlife Service staffers agree that the local managers have a thing or two to learn about wilderness management. A recent document released by the service's national office in Washington, D.C., says refuge managers need wilderness training in order to look beyond managing for one wildlife species.

The Wilderness Society and its legal counsel, the Land and Water Fund of the Rockies, admit that wildlife-related habitat improvements are not legal if they are necessary to preserve wilderness resources. However, they say that the agency has no science to show that waterholes are necessary to bighorns' survival. Waltman says the current bighorn sheep declines are due to natural fluctuations in the population cycle, not dry waterholes.

Bill Broyles, who has studied the benefits of waterholes for the service, says there is no evidence that man-made water developments increase birthrate, help fawns survive or keep bighorns alive during the dead of summer. "There has never been a case when water dried up, and there was a mass die-out," says Broyles, a volunteer with the nonprofit Friends of Cabeza Prieta. "The only case of a mass die-out occurred when there was a water supply that didn't dry up and the sheep died from botulism."

Broyles and other critics of the Arizona Desert Bighorn Sheep Society and the state Game and Fish Department say these groups have a vested interest in keeping the bighorn population as large as possible: the more sheep in the state, the more permits issued for hunting. For the agency, that means more money. For the Sheep Society, that means more happy hunters.

"Many people have sweated and taken off the Fourth of July to haul water," Broyles says. "If you told them they didn't need to haul water, it would be like telling them God is dead."

Wait and see

The issue isn't likely to be resolved anytime soon. Just seven months ago, the Washington office of the Fish and Wildlife Service threw out a recently completed management plan for Cabeza Prieta because it didn't fully comply with the legal responsibilities under the Wilderness Act. Refuge staff just began the process of writing a new plan, which should take two years. Among other things, the two new documents will determine whether artificial water developments are essential to the purpose of the refuge.

In a twist that may make the agency's attempt to create a working management plan irrelevant, the National Parks and Conservation Association is pushing Congress to designate a Sonoran Desert National Park, which would include the Cabeza Prieta National Wildlife Refuge (HCN, 3/29/99: Plans for a new park in Arizona). The proposal for the creation of the 3-million-acre national park eliminates Cabeza Prieta's wildlife refuge designation, and thus the mandate to manage wildlife populations.

The Arizona Game and Fish Department recently began a study on the effects of waterholes in the desert, but it will be at least 10 years before any conclusions are reached. Unless, that is, Tiller gets his wish, and the bighorns speak up.

Beth Wohlberg is an HCN intern.

YOU CAN CONTACT ...

  • The Arizona Desert Bighorn Sheep Society Inc., 480/854-8950;
  • Don Tiller, Cabeza Prieta National Wildlife Refuge manager, 520/387-6483;
  • John Hervert, Arizona Game and Fish Department wildlife biologist, 520/342-0091;
  • Jim Waltman, The Wilderness Society, 202/429-2674.