Blue Planet: How many bears are enough?

By DAN WHIPPLE, UPI Science News  |  April 25, 2003 at 2:36 PM
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The rebound of healthy populations of two large predators in the Rocky Mountains is forcing interests on both sides of the endangered species issue to rethink their definition of when an animal should be removed from the list.

Protective efforts mandated by the federal Endangered Species Act have been very successful at restoring wolf and grizzly bear populations to the ecosystem in and around Yellowstone National Park. But the very success of those efforts now require scientists and conservationists to reconsider whether mere numbers are an adequate criterion for declaring a formerly endangered species saved.

The debate, still in its infancy, goes to the heart of the purposes of the act. Was it intended to save individual creatures? Or should its provisions protect entire ecosystems inhabited by endangered species, thereby creating a "trickle-down" effect for the other animal residents of that ecosystem.

The question isn't really new. When Congress passed -- and President Richard M. Nixon signed -- the Endangered Species Act of 1973, no one then could establish the law's priorities, either. They said its purpose was to protect species of "esthetic, ecological, educational, historical, recreational, and scientific value to the Nation and its people." They went on to list those priorities in alphabetical order.

What's new is certain high-profile animals have recovered -- enough for everyone to consider the next step. At present, 1,820 animals and plants are listed as threatened and endangered, according to the U.S. Fish and Wildlife Service. In the 30 years since passage of the law, the federal government has removed only 26 "true" species and subspecies from that list -- seven of those because they became extinct.

As a rule, USFWS biologists use population to determine whether a species has recovered. Grizzly bear recovery, for instance, is based on a formula of population growth and mortality rates, rather than absolute numbers of bears. In early 1975, the Yellowstone ecosystem harbored only about 225 grizzly bears. At the time, some biologists predicted the animal would be extinct by the turn of the century. Thanks to recovery efforts, the population probably runs about 1,000, although counting them is difficult.

In 1995, no wolves roamed in Yellowstone. When they were reintroduced that year, biologists predicted recovery would be reached when about 100 wolves -- including 10 breeding pairs -- had been established in each recovery area for three successive years. That goal was reached in 2002.

Therefore, the USFWS has "downlisted" wolves -- from endangered to threatened -- in the Yellowstone ecosystem, and the service is in the process of "delisting" the animal -- removing it from endangered species classification altogether. It wants to do the same with the grizzly.

Therein lies the rub. Two scientists who work in the area -- Sanjay Pyare of Montana's Ecosystem Management Research Institute and Joel Berger of the Wildlife Conservation Society -- said although wolf and grizzly bear numbers have recovered in greater Yellowstone, the ecosystem as a whole is not responding as it should to the renewed presence of these predators.

In a paper published in the April issue of Biological Conservation, they argue "different types of ecological data available throughout recovery zones (should) be used in consort with demographic criteria to evaluate when endangered carnivores are more fully integrated in their ecosystems."

In an interview with UPI's Blue Planet, Berger said, "When the American public is told that wolves and bears are being delisted, they may erroneously think that the ecological system has recovered. But maybe 85 percent of the system has not recovered."

There is more involved than the legal mandates, he said. "Our intent is to point out that ... ecological recovery is very different from demographic recovery."

The two scientists studied the response of prey species in Yellowstone -- in this case, moose -- to the renewed presence of predators, and compared it to moose in Alaska. In much of Alaska, moose always have been subject to predator pressures from wolves and bears. Pyare and Berger also looked at a Kenai Peninsula population that lives in a predator-free environment.

They discovered the Yellowstone moose remain naive about the threat from wolves and bears. They don't display the anti-predator behavior that is seen in the other populations.

"A basic anti-predator reaction was lacking in Wyoming," the paper said. "The level of response among Alaskan moose living under virtual predator-free conditions for 25-plus years closely resembled that of conspecifics in Wyoming."

A second question that is emerging -- at least, where wolf status is concerned -- is whether a species can be considered recovered when it has returned to a relatively small portion of its original range. Many environmentalists want to see wolves roaming in other portions of the West where it lived before human settlement.

Rob Edward, director of carnivore restoration for Sinapu, wants to see wolves reintroduced into Colorado. Sinapu, a non-profit organization dedicated to predator protection and restoration in the southern Rockies ("sinapu" is the Ute word for wolves), has filed a lawsuit to try to get the USFWS to do recovery planning for the southern Rockies under the ESA. Edward said he sat in on a conference call about the wolf downlisting rule.

"We wanted to know, 'Will recovery planning begin in earnest?'" he told UPI. "Our answers from the phone conversation were in the affirmative. We want to look at the entire region and write a recovery plan from a biological perspective."

However, Ed Bangs, USFWS's wolf recovery coordinator, told UPI, "Our position is that wolves are doing great in the northern Rockies, and that's where our responsibility ends ... Under the ESA we have done our job."

The USFWS has no statutory authority to place wolves in other parts of the country, Bangs said, though they could migrate there naturally.

If wolves are delisted, their management also delists -- to the state wildlife management agencies. Then, any state wishing wolves within its jurisdiction is free to add them.

"While there could certainly be wolves in Oregon or Washington, that would just be the same wolf in another place," Bangs said. "While there is nothing wrong with that, the ESA is intended to prevent species from going extinct." In the case of the wolf, the agency has done that, he said.

"Some people see it an ecological restoration act, where you put animals back anywhere they can live. You could have gray wolves in Kansas, but they would really be a pain in the butt," he said. "Where do you draw the line? Where does everywhere end? Where is the line of where wolves can't live anymore?"

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