Repertoire of two flying squirrel species in Minnesota and applications for research and conservation

In Minnesota, climate change is enabling the range of southern flying squirrels (Glaucomys volans) to expand northward into historic northern flying squirrel (Glaucomys sabrinus) range. Northern flying squirrels are a species of concern in nearby states and were listed as a vulnerable species in the 2025 Minnesota Wildlife Action Plan. Managers now need current distribution ranges for both species to assess impacts on northern flying squirrel populations. Flying squirrels vocalize in the ultrasonic range with species specific calls. Acoustic detection is a non-invasive technique that has a lower latency to detection and a higher probability of detection than traditional methods like camera traps and live trapping. Establishing the acoustic repertoire of northern and southern flying squirrels across their range will allow for comprehensive development of acoustic filters and streamlined analysis of acoustic data. We used a decade of acoustic data from areas of allopatry and sympatry to determine species distributions. Our data adds Minnesota to the call library for northern and southern flying squirrels. We developed a modified acoustic filter for the state along with an examination of habitat associations. The updated distributions and Minnesota filter provide a strong foundation for future monitoring of these species regionally.