Cooperative Fish and Wildlife Research Units Program: Virginia
Education, Research and Technical Assistance for Managing Our Natural Resources

Virginia Project

Post delisting Surveys of Virginia northern flying squirrels and spruce restoration

October 2021 - December 2022


Participating Agencies

  • US Forest Service, Monongahela National Forest

In the central Appalachians, population estimates of Virginia northern flying squirrels (VNFS) are extremely difficult to obtain due to extremely low trap success and even lower recapture rates . In 2014, 1308 trap nights in high quality habitat produced no captures of VNFS, although 674 nest box checks produced 12 adult individuals (56 box checks/squirrel). Since nest boxes are arranged in lines, population densities cannot be estimated. Additionally, nest box occupancy is generally low, although occupancy rates are steady. Therefore, the scale of the proposed red spruce restoration and low capture success of VNFS make it extremely difficult to determine how restoration may influence population sizes. However, the use of ultrasonic acoustic surveys may be used as a useful monitoring tool to determine the potential effects of treatments on VNFS occupancy of treated low quality habitats and adjacent high quality habitats. Acoustics has been used as a success monitoring tool on the Carolina northern flying squirrel in western North Carolina and to assess the effects of harvest on flying squirrel habitat occupancy. The ability to differentiate between VNFS and southern flying squirrels quantitatively and qualitatively make this survey method suitable in places where both species are sympatric. Pre-treatment acoustic surveys occurred prior to restoration treatments in the Upper Greenbrier on the Greenbrier Ranger District. More restoration treatments are proposed on the Monongahela. We propose the use of ultrasonic acoustics to monitor pre- and post-treatment VNFS occupancy in areas where restoration activities will occur in order to monitor the persistence of flying squirrel occupancy.