Disappearing Prairies May Doom Certain Butterflies

By Jeff Brady
CORVALLIS, OR 2003-03-11 (Oregon Considered)

Think of prairies and the Midwest probably comes to mind. But the Willamette Valley and Puget Sound were once home to vast prairie land that has since been eaten up by cities and farms. Certain butterflies lived in those prairies, and now that their homes are gone they’re on the verge of extinction.

Today, the Taylor’s Checkerspot species can be found in only four places in the Northwest.

The only Taylor’s Checkerspot habitat known to exist in Oregon is about the size of two football fields just outside of Corvallis. In April and May when you walk over the hillside and down to the small prairie, you’re likely to see hundreds of the black, orange and white butterflies.

But this time of year, they’re still caterpillars. At first they’re difficult to find, but Oregon State University Entomologist Dana Ross has an eye for them.

Dana Ross: What we’re seeing here is small, dew-covered caterpillars every foot or so, throughout where we’re standing. So, we’re going to have to be careful that we retrace our footsteps carefully so as not to step on any because there’s probably, literally, hundreds within a five or ten foot radius.

Ross says at this time of year the caterpillars are feeding on their favorite plant a leafy ground-hugger that looks like a weed to the untrained eye. But this plant is special it’s one of only two the Taylor’s Checkerspot will eat.

Recently several environmental groups asked the U.S. Fish and Wildlife Service to put three butterflies on the endangered species list. Scott Hoffman Black with the Xerces Society says the Taylor’s Checkerspot is the closest to extinction. He says development and agriculture have taken over much of the butterfly’s habitat.

Black says the prairie near Corvallis is also under attack from invasive species and encroaching forests. Historically, he says frequent wild fires kept the forest in check.

Scott Hoffman Black: Without fire what you see is conifers mostly Doug Fir crowding in from all sides and it’s going to be really important to manage those trees. Now, that doesn’t mean coming in to do large scale logging or anything like that what that means is coming in and insuring that as the small trees encroach into the site that they are taken out right away so they don’t shade out the host plants and the nectar sources.

Black says one of the four places in the Northwest where the Taylor’s Checkerspot lives is at Fort Lewis near Olympia. Army Biologist Dave Clouse says despite the military’s conservation efforts, the butterfly’s numbers have dropped dramatically.

Dave Clouse: Well, like, in the mid 90s there was one site where there was several hundred observed and then last year, I think they discovered there was only three or four or something like that.

Those few butterflies were found in what the Army calls the impact area in civilian language that’s the bombing range. Clouse says fortunately the Taylor’s Checkerspot is on the edge of the range where its unlikely soldiers will disturb the area.

Scott Hoffman Black with the Xerces Society says prairies like these need protection because there are so few of them left. He imagines a movement developing around protecting and maybe even restoring prairies.

Scott Hoffman Black: I see it as the old growth movement was 20 – 25 years ago. 25 years ago there weren’t very many people talking about old growth. But that had just started and it became a major campaign. I think we now have some voices who are talking about prairies and prairie protection and I see that coalescing to a bigger movement.

Just as the movement to protect old growth trees changed the Northwest timber industry, a movement to protect prairies could affect a variety of groups most notably property developers and ranchers.

Myra Hyde with the National Cattlemen’s Beef Association says the best way to get her members to help butterflies is to use incentives rather than regulations. She says the Xerces Society should work with landowners to improve habitat and bring back the butterflies instead of trying to get an endangered species listing.

Myra Hyde: Once you get into the buttin’ heads situation, you’ve already lost the battle because people are gonna get backed into their corners and they’re gonna start fightin’ for their position rather than try and find a middle ground.

But the Xerces Society and several other environmental groups are pursuing an ESA listing. The U.S. Fish and Wildlife Service has added the Taylor’s Checkerspot to its candidate list. But the butterfly could linger there for a long time before the agency gets the money to assess its status.

In recent years the Fish and Wildlife Service’s work agenda has been largely driven by the lawsuits it has lost. Realizing that, the Xerces Society is considering whether to file the first court case in the group’s history, in an effort to put the Taylor’s Checkerspot at the top of the agency’s to do list.