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Growing up in Michigan, I took the acres of wild blue lupine at my childhood home for granted. Today, I think about lupine all the time, as I recently became the range-wide recovery lead for the Karner blue butterfly. This small, postage stamp-size butterfly is dependent on wild lupine, the only source of food for Karner blue butterfly larvae. One of my mother’s favorite photos of me shows me sitting in a sea of blooming lupine, surrounded by brilliant purple flowers with green umbrella leaves. While it’s tempting to imagine I also grew up with the Karner blue butterfly, it’s unlikely. It has been protected as an endangered species for my entire life.
The small, blue butterfly lives in oak savannas and pine barren ecosystems from western Wisconsin eastward to the Atlantic and is currently found in Michigan, New Hampshire, New York, Ohio, and Wisconsin. Populations are at risk of winking out of existence without regular habitat management or protection to provide the habitat the species requires. In addition to requiring wild blue lupine, the butterfly and lupine occur in habitats that are fire-dependent – that is, they require regular disturbance to limit the intrusion of woody vegetation into open areas and expansion of dense forest cover. Management that replicates these natural processes keeps lupine and other nectar resources on the landscape.
When the Karner blue butterfly was protected in 1992, Indiana Dunes National Park was home to one of the largest populations with 5,000 to 10,000 butterflies. Today the Karner blue is no longer found in Indiana. Despite years of management and habitat restoration efforts, the species has not been observed in Indiana since 2014. After years of declining population numbers, extreme heat and drought in 2012 led to Karner blue butterflies vanishing from Indiana. Impacts of severe weather are a major concern for this vulnerable species.
Becoming an endangered species lead can be an overwhelming experience, especially if the species has been listed for decades. There are boxes and boxes full of history to be absorbed from previous leads and researchers who spent their careers becoming experts on the species. Thank goodness I have their work and our partners to help me step into this role. Over the years, a diverse network of partners from all sectors, including private citizens, industry, academics, Tribes, local units of government, and state and federal agencies, have all directly contributed to the overarching Karner blue butterfly recovery effort. A recovery team was established in 1994 to draft the Karner Blue Butterfly Recovery Plan. Simultaneously, the Wisconsin Department of Natural Resources drafted the Service’s first statewide Habitat Conservation Plan (HCP) for a species. The Wisconsin Statewide Karner Blue Butterfly HCP now has more than 50 partners, and over 792,000 acres are enrolled. Wisconsin is now considered the stronghold for the species – thanks to the Wisconsin Department of Natural Resources, the HCP enrollees, private landowners enrolled in the Service’s Partners for Fish and Wildlife programs, and Fort McCoy, which is home to one of the largest populations of Karner blue butterflies in the state.
Upon stepping into the new role, I learned about an extraordinary effort to complete a comprehensive review of 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 impacts on the Karner blue butterfly. While a report may not be thrilling news to everyone, I was ecstatic! “Blue Snowflakes in a Warming World: Karner Blue Butterfly Climate Change Vulnerability Synthesis and Best Practices for Adaptation” not only synthesizes the existing research on Karner blue butterflies and climate change but also outlines a menu of recovery actions to ensure the species persists into the future. The report is one of the most in-depth looks at an imperiled species, and the recovery approaches we take for the Karner blue butterfly may blaze the path forward for other at-risk plants and animals.
I encourage anyone interested in species recovery, pollinators, or climate change to look at the report when it’s available later in 2023. The climate change report inspires hope for species recovery in a changing climate, and not just for the Karner blue butterfly. The actions highlighted in the report are relevant to a wide variety of species, especially those with similar larval-host plant relationships.
One of the challenges outlined in the report is how sensitive the Karner blue butterfly is to temperature and precipitation changes. The species is limited in its ability to move northward because of the larval-host plant relationship with wild blue lupine. The butterflies cannot move without lupine moving first. Without connecting corridors of lupine and nectar plants, the species is unable to move to new places without assistance. And even more concerning is the disruption that shorter winters and hotter summers are having on the relationship between the flower and the butterfly. The time when the lupine blooms and the butterfly caterpillars hatch is falling out of sync, resulting in some very hungry caterpillars.
While the Karner blue butterfly may be a “snowflake in a warming world,” we are taking steps to protect it. Another element covered in the report is Resist-Accept-Direct, or RAD, and how this framework can be used to evaluate recovery actions. Do we resist the ongoing changes and attempt to reverse impacts, accept change by allowing Karner blue butterflies to respond to climate change without any assistance, or intervene and direct change to areas that may become more suitable for the species in the future? These are just a few of the questions weighing on my mind as I learn more about the species and work with our partners.
This summer I am out in the field, visiting with partners and observing Karners in flight. When I look out across fields of wild blue lupine, I can’t help but be reminded of my childhood. I hope that future generations will be able to see the beautiful, blue butterfly when scanning these lupine fields.
Dawn Marsh, Minnesota-Wisconsin Ecological Services Field Office, Ecological Services, Midwest Region
