Stabilizing the population is key to avoiding the endangered species list

Jeremy Cox,

Chris Guy, a U.S. Fish, and Wildlife Service biologist, and Jennifer Selfridge, a Maryland Department of Natural Resources invertebrate ecologist, check for frosted elfin butterfly caterpillars on a yellow wild indigo bush at a state-owned forest in Worcester County, MD. (Dave Harp)

Frosted elfin butterflies aren’t much to look at. Their 1-inch wingspan and brownish-gray wings give them the appearance more of a moth than a majestic monarch butterfly.

Jennifer Selfridge doesn’t see them that way, though. Thirteen years after her first glimpse of the species on the site of a recently cleared Maryland forest, her voice still crackles with excitement.

“It was fantastic,” said Selfridge, an invertebrate ecologist with the state’s Department of Natural Resources. “A lot of times when you go out to find a species that is rare, you’re lucky to see one or two — and on this day, I saw dozens of them. I lost track of time and got a really bad sunburn.”

Selfridge — part butterfly hunter, part researcher — has channeled that energy into studying the elfin’s mysterious life cycle and coordinating Maryland’s efforts to restore leafy havens for the species. But habitat loss throughout its eastern U.S. range and the butterfly’s own selective diet have all but grounded scientists’ hopes of elevating its numbers.

The butterfly is listed as endangered or threatened by a dozen states — but not by the federal government. After a 2018 species assessment raised as many questions as answers about the elfin population’s health, the U.S. Fish and Wildlife Service this year dispatched survey teams across its range to shed more light on its status.

The agency is set to decide whether to list the species in 2023. In the meantime, officials are collaborating with local governments and nonprofits to improve conditions so that elfins don’t need to be listed.

“Right now, there’s a lack of information about the population,” said Kathy Reshetiloff of the USFWS’ Chesapeake Bay office in Annapolis. “We’re trying to get ahead of the ball, so we don’t have to list the species.”

Why so much fuss over a relatively unremarkable butterfly? Protecting elfins, conservationists say, would go a long way toward preserving their preferred landscape. The species dwell in sunny savannas and pine barrens. Those habitats are rare because they rely on regular doses of fire, mowing or some other type of human hand to keep from getting overgrown and shaded.

Scientists say the loss of such landscapes to overgrowth and development has not only lowered the frosted elfin butterfly’s numbers but also those of the eastern hognose snake, the Karner blue butterfly and two types of birds, the whip-poor-will and eastern towhee.

A frosted elfin butterfly has a wingspan of only about an inch. It is distinguishable by the dappled, “frosted” look along the edge of its wings. (Submitted by Harvey Tomlinson)

Making certain forests more hospitable to elfins has a multiplying effect across the ecosystem, Selfridge said.

“If you put the time in to manage the habitat, it can restore the species,” she said. “It’s just having the will to do that.”

Elfins can be found in 25 states, largely in a belt from eastern Texas to Massachusetts. They don’t appear just anywhere in those states, though. They feed on only two types of plants — lupine and wild indigo — and generally don’t flutter far from them.

Scientists have counted nearly 400 elfin clusters across its U.S. range. But according to the 2018 Fish and Wildlife assessment, which was based on existing scientific literature and input from experts like Selfridge, the condition of more than four out of five of those populations is unknown.

As they prepare their species determination, USFWS officials would like to know how many elfins there really are, where they currently live, what threats they face and whether a more suitable habitat exists. The agency hired survey crews to fan out across the butterfly’s range this spring and summer to help answer those questions.

To understand the plight of the frosted elfin butterfly, follow Selfridge into the field with a group of graduate students and Fish and Wildlife officials.

The setting: early summer on the same property where Selfridge spotted her first elfins. The 600-acre tract has since been sold and is now managed as part of the Pocomoke State Forest. The site is about 30 miles southwest of Ocean City and a world away from its neon lights and tacky T-shirt shops.

The terrain gently climbs and falls — unusual for the otherwise flat-as-a-griddle Eastern Shore. This, Selfridge pointed out, was once a prehistoric sand dune. Today, it’s mostly covered in oak trees, pines, blueberry bushes and goldenrod.

Clad in long sleeves and pants against the mosquitoes and ticks, the pack trudged up a sandy track that used to serve as a logging road. Suddenly, the dense canopy gave way on one side of the path to a bowl of sunshine, where loggers clear cut about 60 acres earlier this year. That should provide fresh habitat for the sun-loving lupines and indigo that elfins rely on, Selfridge said.

She knelt beside an indigo bush on the side of the road and began examining its tear-shaped leaves and yellow flowers as if she were paging through a book.

The frosted elfin butterfly feeds on only two types of plants: lupine and wild indigo. This caterpillar is feeding on yellow wild indigo. (Dave Harp)

“Oh, and we’ve got a caterpillar,” Selfridge announced. A green, slug-like blob was just barely visible on one of the stems.

It often takes a trained eye to spot elfins. To most observers, their only distinguishing characteristic is the frosted-looking tips of their wings.

Elfins spend no more than two to three weeks as adult butterflies. In the mid-Atlantic, typically from late April to mid-June. That short window is given over to a frenzy of feeding, mating and, in the female’s case, finding wild indigo or lupines on which to deposit eggs.

For the next generation, the life cycle goes on: An elfin spends about one week as an egg, five to six weeks as a caterpillar and the rest of the year and the first few months of the next inside a chrysalis.

Selfridge’s research has revealed that elfins that feed on lupines are the same subspecies as the ones whose diets consist of indigo — contrary to what some researchers had speculated. She also has shown that the butterflies tend to spend their pupa stage just above the soil surface, suggesting that land managers ought to be careful with how and when they conduct prescribed burns.

In the Chesapeake basin, elfins are classified as endangered in Delaware and Maryland and threatened in New York. In Maryland, they are found in one cluster in Garrett County on the far western side of the state and in four or five clusters on the Eastern Shore, Selfridge said.

The centerpiece of Maryland’s elfin collection is that 5-acre plot at the end of the Pocomoke forest logging road where Selfridge had first gone looking for the species all those years ago. For some reason, lupines and indigo sprang up here after one particular tree-clearing operation, and elfins weren’t far behind.

Any question about the site’s ecological importance is answered by the pair of electrified yellow wires that surround it. The wires have kept hungry deer at bay for seven years, Selfridge said. She and some colleagues had once tried transplanting some lupine elsewhere on the property to expand the habitat, but it died after their first winter.

After walking the width of the protected area, Selfridge turned back down the logging road. She is optimistic that elfins can avoid the federal endangered species list.

“I’m hopeful we can find more populations, figure out the distribution and do the work we need to do to keep the population stable and increase the distribution,” she said. “If it’s off the list, that means it’s doing better, and that’s what everyone wants to see.”

David M. Higgins II, Publisher/Editor

David M. Higgins was born in Baltimore and grew up in Southern Maryland. He has had a passion for journalism since high school. After spending many years in the Hospitality Industry he began working in...