TWIN LAKE, MI – Several small, silvery-winged butterflies flitted among the native spotted bee balm and butterfly milkweed growing under the hot, summer sun at Muskegon State Game Area.

Wildlife officials say the extremely rare insect is making an important comeback in Michigan. Scientists found several federally endangered Karner blue butterflies this summer in a habitat restoration plot near the Muskegon River.

The return of this colorful butterfly, with its silver and blue to violet-colored wings, tells conservation officials that their oak-pine savanna habitat restoration efforts are working.

“By protecting the Karner blue, we create this umbrella of protection,” said insect expert Ashley Cole-Wick, a zoologist with the Michigan Natural Features Inventory.

“We’re also protecting and managing for all these other species,” she said, “even though Karner is what I like to call charismatic microfauna.”

Karner blue butterfly surveyConservation scientist Ashley Cole-Wick conducts surveys of the federally endangered Karner blue butterflies as they return to areas from which they’d disappeared at Muskegon State Game Area in Twin Lake on Tuesday, July 15, 2025. Cole-Wick is helping the Michigan Department of Natural Resources with ongoing habitat restoration in parts of the forest for native butterfly species.Isaac Ritchey | iritchey@mlive.c

The approximately one-inch butterflies seen July 15 on state land as they sipped nectar from native wildflowers are what’s called an indicator species. That means they are sensitive to environmental changes and can signal a healthy ecosystem.

Natural resources managers in Michigan are learning that Karner blue butterflies will return from meadows and right-of-way zones, where they’ve clung to survival in recent years, if more natural savanna forests are restored.

Cole-Wick said this is welcome news in the face of other pressing challenges for the pollinator species, such as widespread insecticide use and climate change.

State officials learned this type of savanna restoration doesn’t benefit only game species like turkey and deer but also supports some of Michigan’s rarest plants and animals, she said.

Karner blue butterfly surveyThis is a federally endangered Karner blue butterfly at Muskegon State Game Area in Twin Lake on Tuesday, July 15, 2025. Evidence shows the rare insect is returning to restored oak savanna ecosystems in Michigan.Isaac Ritchey | iritchey@mlive.c

The Karner blue butterfly was protected under the federal Endangered Species Act in 1992 because of dramatic population declines attributed to habitat loss and widespread fire suppression.

Experts say the butterfly naturally thrived in Michigan’s oak-pine savanna habitats, droughty ecosystems which need repeated fires to naturally regenerate. That was historically attributed to wildfires or Indigenous cultural burning before European colonization.

However, without those widespread fires creating natural openings for sunlight to shine through the forest canopy, oak trees encroached on these savanna ecosystems over time and shaded out the host plant the Karner blue butterfly requires to survive, native sundial lupine.

In fact, the butterfly requires a delicate balance of enough sundial lupine – scientific name Lupinus perennis – in both sunny and shady spots to stretch through its full flight season. It’s all connected to the butterfly’s annual cycle of two generations per year, Cole-Wick said.

Sundial lupine growing under the full sun is typically greened up and ready for the first hatch of Karner blue caterpillars in the spring. Those caterpillars grow to become the first generation of butterflies.

By mid-summer those early lupine plants are roasted by the sun and already shedding seeds, while lupine plants growing in shade are perfectly primed for the second round of caterpillars to gobble up.

In recent years, land managers at Muskegon State Game Area worked toward that balance of sunny and shady spots for sundial lupine through both timber cuts and prescribed fire. Limited use of herbicides also helps keep native shrubs and trees like black cherry and sassafras from filling in the openings created in the oak-pine forest.

“We’re trying to reduce the overstory cover here so we could get more light to the ground, just like that patch over there,” said Nik Kalejs, wildlife biologist with the Michigan Department of Natural Resources, nodding toward a sunny forest opening.

Karner blue butterfly surveyWildlife biologist Nik Kalejs with the Michigan Department of Natural Resources walks through an oak savanna restoration site at Muskegon State Game Area in Twin Lake, Michigan, during the flight season for the federally endangered Karner blue butterfly on July 15, 2025. The insect is returning to areas from which it disappeared following oak savanna habitat restoration efforts in parts of the forest.Isaac Ritchey | iritchey@mlive.c

“Repeated fire is very important. We’ve had at least three cycles of burns on this piece alone in the last 12-14 years,” he said. “And we have another one on the books for as soon as possible.”

Cole-Wick said researchers found a single Karner blue butterfly within the oak savanna restoration plot at Muskegon State Game Area last year; this season they discovered three. It seems the butterflies come back when savanna conditions are restored, she said.

The Karner blue butterfly’s reproductive dependence on just one species of lupine plant largely limits its population stronghold to parts of Wisconsin and Michigan. The federally endangered butterfly is ranked by Michigan as imperiled and in Wisconsin as a species of special concern.

Limited pockets of the butterflies can also still be found in Minnesota, Ohio, and areas around the Hudson River in New York and New Hampshire.

Karner blue butterflies disappeared in recent years from the Indiana Dunes National Lakeshore, which served as a case study for the species’ exposure to climate change.

Related: Michigan’s rarest butterfly is going extinct. Scientists are trying to save it.

Cole-Wick said additional challenges facing the Karner blue butterfly include use of neonicotinoid insecticides in agriculture and by plant nurseries, plus global warming pushing the insect toward a third hatch late in the season when sundial lupin isn’t available for the caterpillars.

Finally, non-native, ornamental lupine varieties often used in home gardening or landscaping can actually harm Karner blue butterflies by serving as an “ecological sink,” she said.

The federally endangered butterflies are biologically triggered to lay eggs by special receptors on their feet when they land on any lupine variety. The trouble comes later when the hatched caterpillars can only feed on the native sundial lupine, and subsequently starve.

Adult Karner blue butterflies eat nectar from a variety of other native wildflowers, such as spotted bee balm, butterfly milkweed, showy goldenrod, and black-eyed Susans.

If you purchase a product or register for an account through a link on our site, we may receive compensation. By using this site, you consent to our User Agreement and agree that your clicks, interactions, and personal information may be collected, recorded, and/or stored by us and social media and other third-party partners in accordance with our Privacy Policy.