Habitat occupancy models for the frosted elfin butterfly, Callophrys irus

The frosted elfin butterfly, Callophrys irus, is a globally rare Lycaenid butterfly of North America with patchy and isolated populations in remnant pine barren habitat. Many historical populations are presumed extirpated due to habitat loss and other external pressures. Host plant specialization varies across the range, with populations utilizing either wild yellow indigo (Baptisia tinctoria) or lupine (Lupinus spp.). Beginning in 2019, range-wide surveys were implemented by the US Fish and Wildlife Service to evaluate habitat and population status. Data collected from these surveys were used for habitat occupancy modeling to identify habitat requirements and how these may vary based on environmental factors, subspecies, or host plant. These results will help refine management practices and, when paired with non-lethal genetic samples, identify distinct population subunits across the range of C. irus.