July 27, 2005
If you've been following Eric's pieces on sage-grouse, goats, wolves, orcas, salmon, caribou, and other Northwest critters, you may have gathered that NEW is doing research on wildlife in Cascadia--and what it tells us about the health of our natural heritage.
In fact, as we described in a Cascadia Scorecard News article this week, NEW is introducing a wildlife index as part of the Cascadia Scorecard project. The index tracks population counts of five key indicator species--gray wolves, woodland caribou, greater sage-grouse, orcas, and Chinook salmon--and will be released in complete form in Cascadia Scorecard 2006.
The index will measure population counts because they are the most basic assessment of a species' prospects and may reveal how the larger ecosystems that sustain the species are functioning. We're comparing current numbers to historical levels (see chart above); and we'll depict habitat loss through maps that track species’ current and historic ranges. The index may also help identify the policies that are most effective in protecting these species. Here's a bit on each of the five:
- Gray wolves in Idaho and Montana. Wolves--reintroduced in the mid-1990s--are flourishing and helping to re-balance their native landscapes by, for instance, pressuring the elk herds that formerly browsed on streamside saplings. This, in turn, improves beaver and trout habitat.
- Woodland caribou of the Selkirk Mountains, a remote region in northeast Washington, northern Idaho, and southern British Columbia. They are the last remaining caribou to visit the continental US and their continued existence hinges on repairing fragmented landscapes, such as forest clearcuts.
- Greater sage-grouse in Oregon are sensitive to alterations in the vast “sagebrush sea” of the inland Northwest, including ranching, fencing, and invasive species.
- Chinook salmon returning as adults to the Bonneville Dam, the lowest dam on the Columbia River. These mighty fish are a proxy for the Northwest’s once-prolific salmon runs and for the health of the vast river system that binds British Columbia, Washington, Oregon, and Idaho.
- Southern resident orcas that inhabit the inland seas of Washington and British Columbia. For much of the last century, these orcas were under siege. Now, although they are still in jeopardy, conservation efforts have paid off.
We'd love to hear feedback on the index as we develop it, so please add your comments below.
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