Butterflies are Making a Comeback

The success of Cheryl Schultz’s research and her agency partners makes her optimistic about the future of butterflies.

The Fern Ridge Reservoir lies just beyond the western edge of Eugene, Ore. The reservoir itself is surrounded by swaths of woodland and prairie, pockets of which are owned by various federal agencies and conservation organizations. As you’d expect, much of the land has been developed and farmed. In the Willamette Valley, less than 1 percent of what was once native prairie remains.

The land holds special significance for Cheryl Schultz, who more than 25 years ago, as a young, idealistic graduate student, found cooperative partners willing to join her in learning about effective ways to protect butterfly habitats. As butterfly populations were dwindling across the western United States, these agencies and organizations saw species conservation as their mission, and Schultz was eager to help. “I was looking for a way to make real contributions to conservation,” she said.

It turned out to be her life’s work. Schultz, associate professor of biological sciences at WSU Vancouver, wanted to use scientific research for conservation purposes: to construct solutions that would protect the environment while enabling the people who lived in a place to use its resources. The Nature Conservancy happened to be looking for a way to mitigate species declines by buying land for preserves. She decided to make the pros and cons of one potential solution—habitat corridors—her thesis project.

In The Nature Conservancy newsletter, she reached out to stewardship ecologists who were thinking about corridors. “Within a couple of weeks, I started getting letters and calls from reserves across the country saying they were thinking about corridors—corridors for birds, corridors for butterflies, corridors for reptiles and more,” Schultz said. By the time she had completed her thesis on butterfly corridors, she had learned that dispersed habitats—the “stepping stone” approach—would be more beneficial than a long, narrow flyway corridor.

The West Eugene Wetlands Plan is well known in environmental circles for its ability to advance environmental planning through local, regional and federal partnerships. It was an ideal situation for Schultz’s work, because different organizations—The Nature Conservancy, the Bureau of Land Management, the Corps of Engineers and the City of Eugene—were working together to create a conservation strategy with the potential to restore prairie in a stepping stone pattern. Schultz’s solution worked well for them.

While a graduate student, Schultz met her longtime collaborator, Elizabeth Crone, a National Science Foundation fellow at the time and now a professor at Tufts University. Over the last 25 years, they have collaborated on dozens of projects, studying many species of butterflies, including western monarchs, Oregon silverspot and—their primary model species—Fender’s blue.

The Science of Land Stewardship

Schultz and Crone seek to combine ecological theory with natural history to develop management techniques that can benefit butterfly populations, such as planting native species and controlled burning. The goal is to develop “flexible guidance” useful to conservation-minded property owners and agencies.

Their practical approach is exactly what many funders have been looking for. “A lot of inquiries have been coming in,” Schultz said. “That rarely happens, especially in this funding climate.”

This summer, Schultz and Crone’s study of western monarch butterflies made headlines across the country. In a paper for Biological Conservation, they reported that migratory monarchs in the American West have declined rapidly over the past 35 years, and could be extinct as we know them in another 35 years. “In the 1980s, 10 million monarchs spent the winter in coastal California,” Schultz said. “Today there are barely 300,000.” Although the reasons are not yet clear, loss and modification of butterfly habitat and widespread pesticide use are likely culprits, the researchers said.

The U.S. Fish and Wildlife Service, which funded the study, is currently considering whether to list the monarch butterfly as a threatened species under the Endangered Species Act.

“With Fender’s blue, we’ve been doing the science for the last 25 years, and it’s working. For monarchs and other butterflies, I want to leave people with a sense of the possible: It’s not going to happen overnight, but we can do this.”
—Cheryl Schultz

Time to rebuild

The main focus of Schultz’s work, however, is not so much to document risks to vulnerable species but to reverse them. Her studies have generated much hopeful news. For example, several nature reserves adopting study recommendations have made great strides in restoring land for butterfly habitat, reducing weeds and enhancing nectar resources.

In one patch of land owned by the Bureau of Land Management in the Eugene area, for example, the Fender’s blue population has grown from less than 100 to more than 9,000 in 2015. Using experimental fire, weed control and planting of nectar sources, participants in the Eugene Wetlands Plan “took restoration to heart,” Schultz said. “As a result, they will call back and say we have other questions we want answers to, and that will lead to other projects and other questions. I’ve been fortunate to work with good people who really listen and care about using science to do conservation.” Currently, Schultz is working with the Eugene group to discover how best to use herbicides to reduce grasses and increase plants and butterflies.

Schultz has several projects in the beginning stages, including a five-year grant looking at the viability of various species on Department of Defense lands. The project is funded by SERDP—the Strategic Environmental Research and Development Program—which is DoD’s environmental science and technology program. Schultz and Crone will use butterflies as a model system to examine how environmental changes affect endangered populations. The research will lead to three activities designed expressly to improve land stewardship: fact sheets, a decision support framework and meetings with local managers to help make sure the framework addresses their needs.

“We argued that butterflies are a good system to answer their questions,” Schultz said. “Because of their short life spans, we can get several generations in a five-year project.” In the grand scheme of things, why does it matter to see increases in one species of butterfly? “It also means we’re increasing the extent of functional prairie,” Schultz said. “The plant community structure butterflies need requires native plants, bringing back pollinators, which is good for everything. The whole structure of plant communities—the ecosystem—brings back native prairies that were almost gone in some places.”

Schultz is confident that work like hers is making a difference. “We really can come together, do the science, build the partnerships and take the time to rebuild the populations,” Schultz said. “With Fender’s blue, we’ve been doing the science for the last 25 years, and it’s working. For monarchs and other butterflies, I want to leave people with a sense of the possible: It’s not going to happen overnight, but we can do this. Working with Fender’s blue has been a very positive experience. The potential to help turn around other butterfly species keeps me going.” ■

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