The Karner Blue Butterfly Effect

Written By

The Karner blue butterfly at the Karner Blue Butterfly Easement in Concord, New Hampshire. Mason Wheatley/USFWS

The words “butterfly conservation” don’t typically bring to mind a military base. 

Yet the New Hampshire Army National Guard base in the city of Concord has become a force multiplier for the endangered Karner blue, New Hampshire’s state butterfly. Since 2000, this vintage barracks-turned-laboratory been the site of an innovative butterfly captive-rearing program that has added more than 35,000 individual Karner blues to the local population.

This program is a game-changer for the Karner blue, endangered species biologist Maria Tur tells me, as we watch the release of this year’s cohort of butterflies into the wild.

Now the program is inspiring work to support other species that need our help.

From barracks to butterflies 

Once found in a continuous band stretching across 12 states and onward into Canada, Karner blue butterfly populations have fallen dramatically over the years primarily due to widespread habitat loss of the pine barrens and oak savannahs habitat they depend on for survival. The species was listed endangered by the U.S. Fish and Wildlife Service in 1992, and in 1999, New Hampshire scientists worried the state had lost the species entirely. 

But there was an opportunity for decisive action. As part of a mitigation plan developed in partnership with the Service and the state for a new aircraft facility built on pine barrens habitat, the Guard gave New Hampshire Fish and Game funds for 300 acres of habitat restoration, and a 1,600-square-foot space on the state military reservation.

These old military barracks at the New Hampshire Army National Guard base in Concord, New Hampshire are the site of innovative captive-rearing work to restore populations of the endangered Karner blue butterfly and other at-risk species. Mason Wheatley/USFWS
The inside of the captive-rearing lab. Karner blues are kept inside these mesh tents. Mason Wheatley/USFWS

From there, New Hampshire Fish and Game worked with the Service's Ecological Services New England Field Office and other state and federal partners to launch a captive-rearing program, converting the barracks to a makeshift greenhouse, where they began propagating and releasing butterflies every year with the goal of restoring populations in the Concord pine barrens.

Heidi Holman, New Hampshire Fish and Game Biologist and the lead for the captive-rearing program, estimates they’ve released 35,000 Karner blue butterflies out into the wild since the work began in 2000. 

"Having the captive environment gives us a great opportunity to learn about this endangered species in detail," says Holman.

Looking for an opening

Pine barrens at the Karner Blue Butterfly Easement in Concord, New Hampshire. Mason Wheatley/USFWS

What makes the Karner blue so vulnerable to decline is that they’re highly specialized, Holman explains. As caterpillars, they feed only on the leaves of the wild lupine, a perennial plant that grows in dry, sandy soils and is most often associated with – you guessed it – pine barrens habitat.

Historically, wildfires and other naturally occurring disturbances cleared away trees and shrubs in the pine barrens, allowing for grassy openings where both the wild lupine and Karner blue could thrive. 

Wild lupine. Courtney Celley/USFWS

Decades of fire restriction, however, has allowed that vegetation to come back and fill in those openings. That, combined with extensive land development, drove out lupines, Karner blues, and other species native to the pine barrens.

As this unique habitat fragmented over time, Karner blue butterflies were forced into the few pockets of clearings still managed by humans: roadways, powerline corridors, and grassy areas by airport runways.

Today, by mimicking those natural disturbances through controlled fires and by cutting back vegetation, while also planting native species like pitch pine and lupine, the partners are reviving a habitat about as rare as the species they set out to save. 

“If we didn’t know the Karner blue butterfly was in trouble, we would’ve lost this rare ecosystem,” says Holman.

Poster child of the pine barrens

Heidi Holman, Maria Tur, and seasonal technicians walk to release butterflies at the Karner Blue Butterfly Easement in Concord, New Hampshire.

On multiple days in June or July each year, Holman and her team of technicians take a two-minute drive down the road from the captive-rearing lab to the Karner Blue Butterfly Easement, a 28-acre plot of pine barrens habitat administered by the Parker River National Wildlife Refuge and managed for the butterfly’s recovery.

On this particular day, I join the group, butterfly tents in hand, to release the latest cohort of captive-reared butterflies.

“We picked a great day for it,” Holman says, noting the sunny sky.

Heidi Holman walking to release butterflies at the Karner Blue Butterfly Conservation Easement. Mason Wheatley/USFWS

On a warm summer afternoon, the barrens are anything but. Our short walk down a sandy trail through pitch pine and scrub oak leads to a meadow bustling with movement; butterflies of all shapes and colors flit and flutter about, dancing gently between flowering plants and feeding on nectar.

The team call out species as they spot them: swallowtails, skippers, viceroys, and the Karner blues they had released just a few days prior. 

Throughout the walk, Holman points out the signs of their habitat management, including areas of recent prescribed burns, and patches of disturbed ground where wild lupine will soon emerge.

Thanks to the ongoing management here, these healthy restored pine barrens have become home to all kinds of wildlife, from common nighthawks and prairie warblers to wood turtles and eastern hognose – and those are just the ones that have been seen so far. 

“That’s the important thing, “says Simon Doneski, one of Holman’s technicians. “We were protecting this ecosystem for the Karner, but there are so many rare species that we didn’t even know about that are potentially threatened and endangered. We would’ve totally lost those here had it not been for the Karner.”

New Hampshire Fish and Game technician Simon Doneski explains the importance of the pine barrens ecosystem. Mason Wheatley/USFWS

Lessons learned

20 years of captive-rearing and habitat management to support a highly vulnerable butterfly comes with a wealth of knowledge to share. Building off the successes and lessons learned from Karner blue recovery efforts, New Hampshire Fish and Game and the Service are increasingly working together to advance conservation for other at-risk butterfly species in the Northeast region.

One of those priority species is the frosted elfin butterfly, which Holman and her team began monitoring and practicing captive-rearing at the lab in more recent years after the program gained footing. Like the Karner blue, the frosted elfin also depends upon pine barrens habitat and the wild lupine as one of its only host plants. This overlap of habitat means the two species share similar threats, but also opportunities for co-benefits through these conservation efforts.

The frosted elfin, another at-risk species that will benefit from the work of Karner blue butterfly conservation. USFWS

Additionally, Holman runs a satellite lab on the summit of Mt. Washington, where she leads research and management for the priority at-risk White Mountain fritillary and arctic butterflies. Despite the brutal sub-zero temperatures and wind speeds pushing 200 miles per hour, the alpine zone of the Presidential Range is the only known place on Earth where these butterflies can live; this makes them extremely vulnerable to decline as climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
slowly encroaches into higher elevation ecosystems.

Service support for these efforts comes through the Science Applications Priority At-Risk Species program, which provides funding and field support to elevate conservation for priority species. This shared vision and collaboration between the Service and state agencies is essential to advancing this work, says Holman.

By taking the techniques developed through Karner blue efforts and broadening their scope to incorporate other species of concern, the state and the Service can better understand the factors behind population decline – and address problems before they happen. 

“Let’s get ahead of these things,” says Holman. “Let’s be proactive about conservation and protect the landscape at a scale that we don’t have to do this work.”

New Hampshire Fish and Game technician Helena Mieras lightly blows upon a Karner blue butterfly to release it into the pine barrens at Karner Blue Butterfly Easement in Concord, New Hampshire. Mason Wheatley/USFWS

Back in the pine barrens, the team finds a good stopping place for the release and lift up the tops of their mesh tents. Using the tips of their fingers, they lightly shepherd (or softly blow upon them, if they need a little extra encouragement) the butterflies upward and out from their cubes and onward to freedom. 

One Karner blue lingers for a moment on Doneski's hand, lending an extra moment for us to admire the vibrant patterns that paint their wings. One more soft nudge and they're off, back into the pine barrens, carrying with them a message of hope for our species that need it most.

A Karner blue rests upon technician Simon Doneski's hand before returning home to the pine barrens ecosystem. Mason Wheatley/USFWS

Story Tags

Captive breeding
Endangered and/or Threatened species
Habitat conservation
Habitat restoration
Prescribed burning