Rediscovery and ecology of the Capulin Mountain Alberta arctic butterfly: informing data collection for rare endemics

1. Insect conservation in the southwestern United States is hindered by limited information on distribution, phenology, and habitat, especially for small-range endemics. 2. The Capulin Mountain Alberta Arctic butterfly (Oeneis alberta capulinensis F.M. Brown, 1970), a New Mexico Species of Greatest Conservation Need, is restricted to the Raton Mesa Complex and threatened by isolation, low dispersal, and extirpation from its type locality. 3. We surveyed historic and potential sites to document current distribution, refine flight phenology, investigate larval host plant use, and assess habitat condition. Our results confirm extant populations, identify the larval host plant (Festuca idahoensis Elmer), and describe habitat as montane grasslands with limited woody encroachment. 4. A habitat suitability model predicted additional potentially occupied areas, highlighting under-explored habitat for future monitoring. 5. This study provides the first comprehensive ecological assessment of O. a. capulinensis and establishes a framework for documenting poorly known endemic insects to guide future research and survey design.