Living Things A YELLOWSTONE SAMPLER - Yellowstone Treasures - page 414

Wolves in Yellowstone's three-state area numbered over 1,700 in 2011, but state-man-
aged hunting began that year in Montana and Idaho, and in 2012 it was permitted in
Wyoming. The Yellowstone wolf population is declining, not only due to hunting but also
to disease, wolf-on-wolf killings, and—since elk has been their primary prey—the lessen-
ing elk population (see page 342 ) . Wolf project managers continue to watch Yellowstone's
wolves closely, attaching radio collars to as many as possible. But in 2012 hunters killed
seven collared wolves including the alpha animals, hindering research efforts.
Visitors still have opportunities to see wolves in the Lamar and Hayden Valleys, espe-
cially in winter, but they are harder to find than in the first years of this century. Seasoned
wolf watchers continue to set up their spotting scopes and share their sightings with all
who are interested.
Through the introduction of wolves to Yellowstone, the whole ecosystem is changing,
from the grizzlies to the cougars, coyotes, and ravens who all profit directly from wolf kills,
on down through the ecological pyramid. The wolves primarily prey upon elk. Now few-
er elk graze on the aspen and willows, which in turn are increasing on the elk's northern
range, creating more habitat for small animals and birds like warblers. The Yellowstone
area is again becoming a remarkable example of what James Halfpenny, in Yellowstone
Wolves in the Wild, calls a “trophic cascade”—profound effects spiraling down from the top
to the bottom of the natural food chain.
III. MOUNTAIN PASSES
If you love flowers, then the mountain passes in and just outside of the park are places you
must visit in July or early August. High passes within the park are Craig, Dunraven, and
Sylvan, and outside are Beartooth, Dead Indian, Targhee, and Togwotee. All are deep in snow
for eight to nine months each year, and yearly precipitation is about 40 to 50 inches (100-127
cm).
Evergreen trees
In this ecosystem lives one species that doesn't grow well at lower altitudes: the whitebark
pine (Pinus albicaulis), which looks much like limber pine ( page 346 ) , but has much smaller
cones that fall sooner. Its needles grow in groups of five or sometimes more. Mature trees have
whitish bark and short purple cones with thick scales and sharp spines, but the trees may not
produce cones until they're around one hundred years old. In late summer, when the cones
fall and release their tasty and nourishing seeds, birds, squirrels, and bears enjoy the feast.
Now healthy whitebark pine forests are being decimated by a global warming-related disease,