Wolves essential to Western ecology
By BUZZY HASSRICK
Conservation efforts tend to be reactive, focusing on dousing brush fires,
a Denver conservation biologist says.
To switch that tendency and be more proactive, the Southern Rockies
Wildlands Network proposes a restoration plan “for nature and what nature
needs,” Brian Miller, Ph.D., of the Denver Zoological Foundation says.
Essential to the plan is carnivores, especially wolves. Their role was the
topic of his talk Tuesday during the Lunchtime Expedition Series at the
Buffalo Bill Historical Center.
He is examining the impacts of wolf reintroduction on the mammal community
in Grand Teton Park. His research focuses on the role of top carnivores in
regulating ecosystem processes and ways to improve protection for them.
The restoration plan, rather than banning development, says “yes to life,”
he adds. Stretching from southern Wyoming to northern New Mexico, the plan
– a year away from being final – identifies core areas and their
connections, running along the spine of the Rockies and encompassing
mostly federal lands.
“It’s a work in progress,” Miller adds.
Forces formed the territory. About 30 million years ago, tectonic plates
created the southern Rockies, followed by volcanic and glacial episodes.
Elephants, camels, lions, horses and saber-toothed tigers populated the
land until man arrived 10,000 years ago, and 75 percent of the megafauna
were lost.
When the initially nomadic peoples began parceling up and settling the
land, environmental problems began.
“It accelerated nature’s decline,” he says, through the loss, decline and
degradation of ecosystems and natural processes, the fragmentation of
habitat, invasion of exotic species, pollution and climate change.
The decline led to the displacement of animals, caused by the
proliferation of outdoor lighting, killings, roads, pollution and
sterilization of earth.
“Much of the plan is based on the loss of carnivores because of the level
of their persecution and amount of decline,” Miller says. “They’re key to
restoration.”
Carnivores sit at the top level of a three-tier system, under the “green
world hypothesis,” he says. Plants lie at the bottom, and herbivores
occupy the middle.
When carnivores control herbivore productivity, and herbivores control
plant productivity, all three flourish. When carnivores are removed,
plants and prey suffer. The presence of carnivores causes the prey to
change their behavior.
“The prey becomes less lazy, more active,” Miller adds. And the carnivores
create ecological boundaries between prey species.
Without carnivores, prey compete, one dominates, and the result is less
species diversity, he adds. The interaction also affects the division and
abundance of birds, small mammals and insects.
The same three-tier system worked with sea otters, urchins and kelp, adds
Miller, who says it applies to wolves, elk and plants.
Wolves are a “keystone species” for elk control and ecosystem health, he
said. His preliminary observations in Grand Teton show the willows and
aspen are regenerating as the wolf’s presence causes the elk to limit
their browsing and move more.
“Beaver are returning,” he adds.
The plan linking core areas would restore a regional ecosystem.
“The goal is to reunite a network where large carnivores can live,” Miller
says.