How hikers (and spring skiers) can help protect the endangered and threatened White Mountain Fritillary and the White Mountain Arctic butterflies.
By Lily Hartman
The alpine zone in the Presidential Range of New Hampshire begins at about 4,900 feet in elevation, according to NH Fish and Game, where the last of krummholz, such as black spruce and balsam fir, begin to fade. Tundra flora, such as Diapensia lapponica, mountain cranberry, and Bigelow’s sedge, spread across the treeless landscape and sprout close to the ground in order to shield from exposure. High wind, low temperatures, and unexpected precipitation move through the rugged landscape of bedrock, talus, and gravel on any given day of the year. Throughout this habitat lives unique, lowland species that rely on this fragile ecosystem to not only survive, but thrive in their environment—such as the White Mountain Fritillary and White Mountain Arctic butterfly.
“If [these butterflies] disappear, they live nowhere else except the Presidential Range of NH, so that’s really on us as the citizens of NH [to protect them],” says Heidi Holman, wildlife biologist at NH Fish and Game.
The White Mountain Fritillary (above) eats multiple plants, such as violets, willows, and bilberries. Photo-by-Rob-Nute.
Holman leads the projects to study these butterflies to understand the species better and protect them from threats, such as climate change and recreation. NH Fish and Game recognizes the White Mountain Fritillary as an endangered species and the White Mountain Arctic as a threatened species in NH. An “endangered species” is one that is in danger of extinction throughout all or a significant portion of its range. A “threatened species” is one that is likely to become endangered in the foreseeable future throughout all or a significant portion of its range.
The White Mountain Fritillary is found in wet communities with lush vegetation, such as snowbanks, where snow gathers significantly and lasts late into spring. This creates a moist environment with various plants, which Holman says may be what this butterfly needs to keep from drying out and survive the winter. This type of habitat includes a lot of rare plants that the White Mountain Fritillary nectars on, such as goldenrods and asters. According to Heather Siart, a graduate student who has been working with Holman on various butterfly projects since 2017, the White Mountain Fritillary eats multiple plants, such as violets, willows, and bilberries, which they discovered in recent years.
“If the host plant is susceptible to climate change conditions itself, habitat [for the White Mountain Fritillary] could be reduced,” says Holman.
The White Mountain Fritillary is only a full-grown adult for about a week and flies during the month of August on nice days. It is a beautiful orange and black butterfly that is as small as a half dollar, with wings that reflect patterned, zig-zag lines (unlike other White Mountain Fritillary, which usually have a spot pattern). According to Holman, they take two full years to complete their life cycle. This means that the White Mountain Fritillary has to be managed as two different species—an odd year and an even year—which increases its risk of disappearing completely since it can’t interbreed. Holman and her team are examining if this can be shifted.
A White Mountain Arctic sitting on a rock on Mount Washington. Photo by Samantha Derrenbacher
Similarly, the White Mountain Arctic strictly takes two years to become an adult. It is a dark brown and white butterfly that only lives around the cone of Mount Washington (an even shorter range than the White Mountain Fritillary, which has small pockets of habitat from Mount Eisenhower to Mount Madison). Siart says that the White Mountain Arctic only lives from Bigelow Lawn (out toward Mount Monroe; around Crawford Path) to Monticello Lawn (right off of Mount Jefferson; going towards Mount Washington), and that’s their entire range.
This butterfly purposely tries to blend in with the rocks to shield itself from harsh conditions and predators because it can only fly 2 to 3 feet off of the ground. This is a better defense mechanism since it can’t fly away as quickly as the White Mountain Fritillary.
The White Mountain Arctic can be spotted on nice days in late June through most of July within sedge meadow areas. Its caterpillar grows slowly and only feeds on Bigelow’s sedge—making it much more vulnerable to trampling and the effects climate change can have on its food source. “You’re worried about trampling the vegetation, but you’re not thinking about the little caterpillars that are feeding on those plants,” says Holman.
Holman says, “With these two species, we’re writing a status assessment to help determine if they need federal protection,” which would include recreational impacts, trail use, and off-trail hiking.
Hikers, backcountry skiers, and tourists can help protect these species by simply staying on trail. Since backcountry skiing occurs in snowbank areas, access to these ski routes could mean stepping on plants where the White Mountain Fritillary may live. In addition, a lot of backcountry huts are built near springs for access to water—a common wet area for the White Mountain Fritillary to inhabit. Backcountry explorers should be mindful of staying around developed parts in these locations.
A few years ago, both Siart and Samantha Derrenbacher, fish and wildlife biologist at U.S. Fish and Wildlife Service (USFWS) developed #FritillaryFinders (which now also includes the White Mountain Arctic), both on Instagram (@fritillaryfinders) and Facebook (www.facebook.com/fritillaryfinders), which allows the community to get involved by taking a photo and sending in the location when they spot the butterflies.
The iNaturalist and eButterfly apps are also great places to share this information. “[This data] helps us understand the range of where the population is, how many numbers are out there, and also the time of year that they’re out there,” says Siart.
Siart says that for the White Mountain Arctic project, they are hoping to get the first-known estimate of how many of them there are to determine if their numbers are dwindling or increasing. “I think that’s something that’s still really a big blank space and a mystery for us,” she says.
Butterflies are good indicators of whether or not an ecosystem is healthy and what’s going on in that habitat.
This is because of their short life cycle and vulnerability—meaning their effects can be seen earlier than other plants and animals in that habitat. “If you know enough about them, you can pinpoint what is causing it, and there are ways that some of that can be mitigated,” says Siart.
These butterflies not only have a right to exist, they’re also an important part of the ecosystem. They are food for animals, such as spiders and birds, and pollinators in the area, which helps keep plants alive. Therefore, their disappearance can throw the ecosystem off balance. “It’s like a giant puzzle, says Siart. “They’re just this one piece that helps to complete that entire ecosystem.”
