Wolves Return as Kings of the American Serengeti
12/10/97
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Headline: Wolves Return as Kings of the American Serengeti
Source: The Christian Science Monitor
Date: 12/10/97
Byline: Todd Wilkinson
Copyright 1997 by Christian Science Monitor
Reintroduced to Yellowstone two years ago, wolves have now
halved the coyote population in some places during a turf war.
As biologist Jennifer Sheldon knelt over the coyote's body, it took
only a moment for her figure out what had happened.
The signs were clear: The animal had been killed by a pack of gray
wolves - another example that here in Yellowstone National Park it has
literally become a dog-eat-dog world.
Ever since 14 Canadian wolves were transplanted into this venerated
American nature preserve two winters ago, a ruthless turf war has
ensued between the newcomers and their smaller but prolific coyote
cousins.
It is a battle among predators being played out in the park's
Northern Range, a landscape considered as biologically fecund as East
Africa's Serengeti Plain. No one knows how it will end. But the rapid
ascendance of wolves here on Yellowstone's snowscape - home to the
greatest concentration of large mammals on the continent - is giving
scientists pause. It's also providing fresh insights into the
complexities of reintroducing large carnivores into a dynamic
ecosystem.
``We knew there would be conflict between wolves and coyotes, but
the degree of violence we've witnessed has been startling,'' says
Robert Crabtree, a coyote expert documenting the phenomenon with Ms.
Sheldon, who is also his wife. ``I guess you could say this is
nature's version of mano a mano.''
Yellowstone's lead wolf biologist, Doug Smith, says the
interspecies battle for superiority, in addition to the broader impact
that wolves are having on the ecosystem as a whole, is helping
scientists better understand the reintroduction of native species, a
controversial but growing practice in the United States.
Ironically, coyotes are being purged from the niche they inherited
70 years ago when bounty hunters exterminated wolves from the park.
However, it appears the coyote's loss may produce big dividends for
other animals.
In the wolf's absence, coyote numbers swelled to unnatural levels,
resulting in depressed numbers of pronghorn, beaver, and ground
squirrels, says Mr. Crabtree, who is now halfway through an
unprecedented 15-year study of 500 coyotes. The drop has meant less
available prey for other predators and the loss of beaver-created
wetlands, which are important to moose and songbirds.
Yet, like a rock falling on the calm surface of a pond, wolves have
caused biological ripples in all directions.
``What's impressive to me is how this reveals the complexity of
these systems and how one species, be it a coyote or a wolf, can
trigger off a whole stack of dominoes,'' says Hank Fischer, the
northern Rockies field representative for Defenders of Wildlife.
``We're just beginning to get a glimmer of what's in store.''
The biological diversity in the park's Northern Range - packed with
bison, elk, bighorn sheep, mountain lions, grizzlies, and now wolves -
makes this an exceptional laboratory. ``Where else do you have the
full original complement of predators that existed prior to the
arrival of Columbus?'' Crabtree asks. ``What makes Yellowstone so much
like the Serengeti is that for a researcher it is open and accessible.
You can see the interactions play out right before your eyes.''
Wolf packs have attacked coyotes, killed their young, invaded their
dens, and made the shaggy wild dogs, which were commonly sighted by
tourists only five years ago, a rarity.
``Wolves have really reshaped the presence of coyotes in
Yellowstone, not just in reducing their numbers but forcing them to
the perimeters of their home ranges,'' adds John Varley, director of
the Yellowstone Center for Research. ``They way they've done it hasn't
been pretty.''
Yellowstone officials attribute an increasing number of attacks on
coyotes to the fact that wolf packs are colonizing wider areas of the
park and solidifying the perimeters of their territories. And Sheldon,
whose field work is being supported by a grant from Defenders of
Wildlife, notes that the number of coyotes in the Lamar Valley has
dropped 50 percent. That includes a 30 percent reduction in the number
of coyote packs and a 33 percent reduction in average pack size.
``Often nature's changes are so gradual as to be undetectable in a
human lifetime,'' Sheldon says. ``What has been so compelling about
wolf restoration is to see the immediate and profound responses which
have occurred in just 2-1/2 years.''
Prior to 1995, few North American researchers could boast of having
observed the deadly interaction between coyotes and wolves firsthand.
But during the past 18 months, Sheldon, Crabtree, and a team of
assistants have documented 30 instances where wolves have swarmed
coyotes, and a third of those encounters have resulted in coyote
deaths. They know it represents only a fraction of the toll.
The drama in Yellowstone has attracted national attention because
it hints at what may lie ahead for other ecosystems. Every other
region where wolf reintroduction is currently proposed - the
Adirondacks of New York, the Olympic Peninsula of Washington, southern
Colorado, and New Mexico - also has healthy coyote and big-game
populations.
And while wolves are yielding obvious benefits for Yellowstone,
ranchers still grumble about what will happen when more wolves move
outside Yellowstone. Over the past three years, Defenders of Wildlife
has compensated nine ranchers about $12,700 for 86 sheep and five
calves.
Still, the livestock losses are below what was predicted in an
environmental review that cleared the way for the wolves' return,
although Fischer admits that 1997 has seen the largest percentage of
wolf-killed livestock.
Meanwhile, the Yellowstone wolf population continues to grow.
Today, augmented by the shipment of another 17 Canadian wolves in
1995, it has grown to 86 free-ranging animals, including 46 pups born
last spring and summer.
With the government's goal for wolf recovery here set at 10 packs
numbering 10 animals each, there is already talk of removing this
population from the list of federally protected species.
``Nobody expected we would have this level of wolf reproduction
this quickly,'' says Fischer. ``We are very close to achieving
recovery goals, and with a good crop of pups, that could happen next
year.''