San Bernardino Flying Squirrel Use of Residential Areas: A Citizen Science Approach

Abstract

The San Bernardino flying squirrel (Glaucomys oregonensis californicus) is a California Species of Special Concern restricted to montane forests of southern California. We confirmed the distribution of this species in residential areas of the San Bernardino and San Jacinto Mountains with the assistance of citizen scientist volunteers. Project participants placed motion sensor camera traps near bird feeders on their property and uploaded their results to a project webpage and associated iNaturalist project. Flying squirrels were documented at all sites monitored in the San Bernardino Mountains but were not detected in the San Jacinto Mountains, consistent with survey results in recent decades. Forest structure plots between the 2 ranges differed in tree density, tree height, litter depth, and canopy closure, but it is unclear whether these differences alone can explain the lack of detections in the San Jacinto Mountains. Habitat in residential areas may provide subsidized food and water resources that are attractive to flying squirrels and important to their persistence, especially in seasonally dry forests and areas subject to prolonged drought, such as those in the study area.