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The Carson Valley Wood Nymph once ranged up and down the Sierra foothills but now can be found only in a single meadow in Douglas County. AP Photo

Monday, July 09, 2001
Copyright © Las Vegas Review-Journal

SHRINKING HABITAT: Scientists try to save rare Nevada butterflies

Summer of study to focus on fate of 15 subspecies

RENO -- Along the Sierra Nevada foothills in Douglas County lies a swampy meadow where two types of butterflies soon should be fluttering about, living in the ever-damp area as if nothing is wrong.

But something is wrong.

While their habitats once stretched up and down the Sierra foothills, the Carson Valley Silverspot and Carson Valley Wood Nymph now are found only on that single plot of land and soon could disappear altogether.

Throughout the northern and central portions of the state, 15 subspecies of butterflies face similar situations of shrinking habitat and possibly extinction.

That is why University of Nevada, Reno scientists are embarking on a study this summer to learn whether more of these rare butterflies exist and what might be done to protect them.

"These butterflies have distributions that are so narrow that an accident or an unintentional adjustment of land use can make them disappear literally in a finger snap," UNR biologist Dennis Murphy said.

"Somebody reroutes water from an area that has a robust riparian community, somebody puts three times the normal amount of cows onto a pasture without knowing what the potential impacts are, we could see some of these butterflies disappear."

With about $50,000 from the federally funded Nevada Biodiversity Initiative program, five scientists will scour areas where they know the butterflies are found and expand their searches to areas that might contain suitable habitats for the rare insects.

"A lot of our work is to cover many, many miles in hiking boots with a butterfly net, looking for new locations," Murphy said. "A lot of this territory is many dozens of miles from pavement. Much of the potential suitable habitat doesn't have roads going to it. It's a real expedition to find these species out in the untrammeled corners of Nevada."

Murphy said officials expect that the extraordinarily dry season might skew their data collection because many of the butterflies breed in some of the wettest locations in the state. And the mountain snow melting faster than normal and an early dry season might have caterpillars transforming into butterflies earlier.

"If the butterflies cooperate, we should have a much better understanding of all 15 butterflies by the end of the season," Murphy said. "But one has to keep in mind this was a fairly dry year. ... Dry years tend to manifest in fewer individual butterflies. And some populations, they may not fly at all. We're working against the vicissitudes of the Great Basin climate."

There are more than 200 species of butterflies throughout Nevada. Because of the state's mountains and valleys, those butterflies are found in patchy distributions, creating what is called "high speciation." As a result, Nevada has more than 700 subspecies of butterfly.

Murphy said the scarcity of many of the butterflies comes from the lack of water in Nevada's desert landscape.

The Carson Valley Silverspot is a good example.

"When you drive down Highway 395 toward Gardnerville, Minden, and look out toward Genoa and so forth, you see wet areas. Even those aren't wet enough," Murphy said. "It's a very tough butterfly to study because you walk into (the area) and sink to your knees due to the muck. And that kind of seeping water coming off the Sierra is not abundant."

The Carson Valley Silverspot, which lays its eggs on violets, is a brilliantly orange butterfly with silver spots on the underside of its wings. Its wingspan is about 3 1/2 inches. The females have a bluish color to them besides the orange.

The goal of the study is to find out which subspecies are in the most danger of extinction and protect them without a listing under the federal Endangered Species Act.

Peter Brussard and other UNR scientists fear federal listing would do more harm than good.

"It's just much more difficult to achieve effective on-the-ground conservation after a listing occurs, in my opinion," Brussard said. "It would tie everything up in lawsuits from now until doomsday and not get anything done for the species."

After the study is completed, UNR officials say they want to work with landowners and federal agencies to create effective conservation plans.

"For these species, probably a half-mile of barbed wire and the recognition by the folks out on that rural landscape that the butterflies are there, and they'll be with us for a long time," Murphy said.