Study
looks at elk behavior
By Jessianne Castle EBS ENVIRONMENTAL & OUTDOORS EDITOR
BOZEMAN – Hike through the mountains in Montana and you’re
increasingly likely these days to see the red hues of dying forests. In some
places, the pine trees have long since shed their dry needles, their arthritic
limbs merely ghosts of the mountains.
The cause of this decline in forest health—with implications for
lodgepole and whitebark pine, to name a few species—is largely the result of
the native mountain pine beetle. And as forests change from dense and green to
bare, open stands, wildlife is taking note.
According to a study conducted by biologists with Montana Fish,
Wildlife and Parks, elk in the beetle-killed Elkhorn Mountains south of Helena
are changing their use of the forest. While a change in habitat from beetle
infestation appears to be only one component of the way elk use the landscape,
a study released in August indicates that elk use the dying forests less in the
summer and fall.
Researchers
say an elk’s use of the forest is largely related to cover and security needs,
and various forest types provide a range of overall canopy cover and protection
from predators and human hunters. While stands of dead lodgepole pine have more
cover than healthy Douglas fir and ponderosa pine forests, the infected
lodgepole remain less secure for elk than their healthy counterparts.
For the
Elkhorn study, biologists radio collared 60 elk and followed their movements
over the course of four years; they found that elk are using public land less
now than during a study conducted in the 1980s, prior to beetle infestation. The
phenomenon might be attributable to the differences in hunting pressures
between public and private land, and the lack of adequate security on public
land due to dying trees.
A large
portion of the study area included the Elkhorn Wildlife Management Unit, which
is the only U.S. Forest Service wildlife management unit in the country. FWP
manages the area for hunting and releases a limited number of cow and young,
spike bull elk tags, and the department also offers permits for larger bulls,
which is the most difficult elk permit to draw in the state.
In an FWP
press release announcing the completion of the study, FWP supervisor Mark
Deleray said elk management is complicated in Montana.
“It always
involves public hunters, private landowners, various land management agencies
and changing habitat conditions,” he said. “This study gives us important
information on habitat and the needed security to help keep elk on public lands
during the hunting seasons.”
Overall,
according to the release, the new findings will inform future land management,
“to provide adequate security for cow and bull elk during the hunting seasons
and discourage elk redistributions to private lands. Similar to many areas in
Montana, private land surrounding public land can be a beacon to elk when the
hunting pressure increases on public lands.”
“The places
in Montana with the worst beetle kill are places with thick lodgepole
forests that are conducive to infestation,” FWP research biologist Kelly
Proffitt said in an email to EBS. “We have been actively conducting research
about elk security in Montana for several years … This is a big issue well
beyond the Elkhorns.”
She added
that FWP wants to better understand the overall health of our public lands and
how to keep elk on public land rather than see them redistribute to private properties.
Proffitt said as FWP learns more about elk movement, the department can work
with the Forest Service and Bureau of Land Management in how to better manage
public lands for wildlife.
As one
example, Proffitt described a research project on beetle-kill in the Sapphire
Mountains south of Missoula. After the Forest Service modified travel in that
portion of the forest, they saw an increase in elk security by 30 percent.
While FWP is
actively researching the larger impacts of mountain pine beetle, scientists
have been studying the bug itself for a number of decades. The mountain pine
beetle bores into the bark of healthy trees in order to lay its eggs, and once
hatched, the larva feed on the host tree, eventually girdling and killing the
tree. The mountain pine beetle is one of an estimated 600 different bark beetle
species in the U.S.
In recent decades, the prevalence of mountain pine beetle is
continuing to increase across the Western U.S.
According to Jesse Logan, the former project leader for the Forest Service’s
Interior West Bark Beetle Project, mountain pine beetle populations appear to
be under the direct influence of seasonal temperature. Logan, who retired in
2006, found that as trending temperatures rise, pine beetles are able to
survive through the winters and at higher elevations; a warming climate is
giving these tree-killers the perfect setting for extensive outbreaks.
Logan notes, however, that while beetles have seemingly devastating
impacts on our forests, in large part they serve a natural process for
lodgepole: beetle-killed lodgepole forests fuel wildfires that lead to tree
regeneration decades later.
But Logan’s
sentiment flips when the conversation turns to the question of whitebark pine,
a high-alpine tree species that has come under beetle attack due to climate
change. In an article published in 2004 by “High Country News,” Logan told the
reporter, “When I see outbreaks intensify in the lodgepole pine, it’s an
interesting ecological event. When I see a 700-year-old whitebark pine go down,
I have a completely different reaction. It breaks my heart.”
