A study by Oregon State University
ecologist Bill Ripple has, for the first time, linked the welfare of
wolves to the welfare of grizzly bears in the Yellowstone National Park
ecosystem. This was big news when the story broke in August, which means
that either the story hit during the doldrums of the 24/7 news cycle,
or that grizzly bears and wolves have been promoted to front-page fodder
by the mainstream press.
My guess: It was probably a bit of both.
My reaction to the stories about this new study was a resounding, “Duh.”
I’ve been reading and writing about wildlife recovery for a very long
time, so this kind of biological symbiosis seemed a given.
I reached Bill Ripple about a week after
the study was published in the Journal of Animal Ecology, just as the
newspapers began reacting to his findings. Most treated the story as if
Bigfoot had been caught on a security camera stealing candy bars from a
7-11 store, i.e., as a huge and unexpected surprise.
Wolves and grizzlies: How could this be
news? I asked Ripple. Weren’t these creatures top predators that
coexisted on the American High Plains for thousands of years? Yes, he
said, adding that his study’s findings have as much to do with politics
and the courts as they do with critters in the wild. How so? I asked.
The impetus for Ripple’s study came in
2011, when the U.S. Fish and Wildlife Service removed the wolf from the
endangered species list. Wolf killing resumed immediately after an
85-year hiatus; 1,500 wolves have already been killed in Idaho alone. At
the same time, the U.S. Fish and Wildlife Service decided to delist
Yellowstone’s grizzly bears, though the 9th Circuit Court of Appeals
wasn’t buying it. The court ruled that the federal agency had not
adequately explained how the demise of the whitebark pine, a principal
high-country food source for the bears, would not threaten their already
precarious existence. These concurrent events prompted a “green fire”
moment for Ripple — a reference to Aldo Leopold, the father of the
modern conservationism, who described the light he saw in the eyes of a
dying mother wolf. That green fire led Leopold to the realization that
predators were intrinsic to the natural world.
Though Ripple said he had studied
Yellowstone wolves since their reintroduction in the mid-1990s, he
decided he needed to make a closer and more detailed investigation of
the relationship between wolves and grizzlies. What he discovered turned
out to be very old news. The symbiotic relationship between the wolf
and the grizzly was documented in petroglyphs on cave walls. These two
beasts of the Northern wild have been engaged in a fascinating survival
dance that began at the end of the last Ice Age.
Ripple’s findings stand on the
shoulders of his earlier work on the ecological effects of wolves and
elk, which found that the re-introduction of wolves to Yellowstone
reduced the size of the elk herd, and, in turn, relieved foraging
pressure on berry-bearing shrubs that comprise a critical food source
for other species, including grizzlies. Surprise #3,474: All of these
relationships come back to food and how one species impacts the food
sources of another.
“We developed four different data
sets to show that the re-introduction of the wolf to Yellowstone has
had much deeper and more far-reaching effect on the flora and fauna of
that ecosystem than we realized,” said Ripple.
As wolves reduced the size of the elk herd
in the Yellowstone ecosystem, chokecherry, serviceberry and huckleberry
flora began to rebound and flourish in a long-term phase of “passive
restoration,” Ripple said. In time, and as other food sources declined,
berry production might become more and more important as a source of
nutrition in the grizzly bears’ diet.
It’s humbling, Ripple added, to realize
that the cascading effects of wildlife management, or mismanagement,
roll in both directions. If too many wolves are killed, the consequences
could affect many other species.
“But if we let passive
restoration run its course, we might just see some remarkable things
happen,” said Ripple. The riparian environment could once again become
vibrant nurseries for birds, beaver, and a number of smaller critters.
If you kill too many wolves in Yellowstone, however, their population
could drop below the threshold essential to maintaining a vigorous and
resilient ecosystem.
If that happens, we might as well
paint over the petroglyphs, cage the animals, pave the parks, dam the
last free-flowing rivers, turn the last old-growth forests into
toothpicks and stop pretending that we cherish the wild.
Paul VanDevelder is a contributor
to Writers on the Range, a service of High Country News (hcn.org). The
author of Savages and Scoundrels: The Untold Story of America’s Road to
Empire thru Indian Territory, he lives in Oregon.
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