BY ROGER HAYDEN
02/05/16
The U.S. Fish and Wildlife Service has indicated it plans to remove the iconic Yellowstone grizzly bear from protection under the Endan-gered Species Act early this year.
The federal agency’s plan is irresponsible and premature because grizzlies are struggling to adjust to declining food sources, even as they face an uncertain future caused by climate change. Respected non-government scientists say the jury is still out on the conse-quences of the bears losing important food sources such as whitebark pine seeds and cutthroat trout. Government scientists, however, insist that the animals are resilient and will adapt.
Just how many grizzlies we’re talking about continues to be a matter of debate. The Interagency Grizzly Bear Committee that monitors the bears recently estimated Yellowstone’s population at 714. But once the 59 known mortalities for 2015 are subtracted, that leaves a population of 655, down 14 percent from 2014’s population.
Since 2002, the Yellowstone population has remained essentially flat. But if it continues to decline at the recent rate, the bear population will drop close to 500, the point at which the animals could again need federal protections. That is why it makes sense to protect them now, at least until there’s more certainty about their survival.
Grizzlies are difficult to count, and the methods the government uses are arcane, highly inaccurate and not totally transparent. Because we are unsure about the size of the population–a number that is key to a delisting decision–why don’t we find a better way to count?
DNA hair analysis is a more accurate method that has been used to count small populations in Canada. The downside is that it is a costly, labor-intensive method that would likely take at least two years to complete. Given that political pressure to delist grizzlies is so intense in Montana, Wyoming and Idaho, it is very unlikely that bears will be counted using this method.
Grizzlies were first listed as endangered in 1975. The world the bears live in has changed dramatically since then. Warming temp-eratures have created conditions in which insects and disease have infested and killed most of the whitebark pine in the bear’s habitat.
The bears’ second major food source used to be cutthroat trout, but the fish began declining in the early 1990s after somebody illegally introduced lake trout to Yellowstone Lake. The large fish preys on the smaller cutthroat, which used to spawn in tributaries to the lake, where grizzlies could catch and eat the fish. Lake trout are deep-water fish out of the grizzlies’ reach.
The remaining major food sources are army cutworm moths, on which 45 percent of Yellowstone female grizzlies feed, and meat. Bears can consume elk or other prey, but they have to wander in order to find it, and the search takes them farther from their core habitat and into areas where they face a greater likelihood of conflict with humans. More than 80 percent of grizzly deaths result from interaction with humans, primarily through vehicle collisions, hunter encounters or livestock depredation.
This rise in conflicts and subsequent mortalities, combined with a population that has grown little since 2002, has created an unsustainable trend, according to grizzly scientists outside the federal government. Scientists like David Mattson, who worked for the Interagency Grizzly Bear Committee for many years, warn that we haven’t yet seen the full impacts of the recent decline in grizzly food sources. It may take more than 10 years before we have a definitive answer.
Given these changes to the grizzlies’ world, the population, in fact, may have entered a period of decline, Mattson contends. The three states that will have jurisdiction over grizzlies after delisting have already announced that they would allow sport hunting of the bears. Considering the many challenges the bears already face, this undoubtedly would accelerate their drift back to the brink.
Grizzlies are one of the slowest-reproducing mammals in North America. If conditions are right, a female gives birth every three years. Because of this slow reproductive rate, negative habitat changes that affect the overall population are difficult to immediately detect. There is a substantial lag time.
Given this level of uncertainty in an environment that is changing—and changing mostly in ways that don’t favor the grizzly—why rush to delist? We’ve worked hard for 40 years to bring the bear population up to recovered numbers. This is no time to risk losing all that we’ve gained in the face of threats we don’t fully understand.
Roger Hayden, a Writers on the Range/HCN contributor, is managing director of Wyoming Wildlife Advocates in Jackson, Wyoming.