Spring and Fall Diet of the Endangerd West Virginia Northern Flying Squirrel (Glaucomys Sabrinus Fuscus)
Mitchell, Donna, The American Midland Naturalist
ABSTRACT.-Fecal pellets from 115 federally endangered West Virginia northern flying squirrels (Glaucomys sabrinus fuscus) were collected in the Monongahela National Forest, West Virginia during the spring and fall in 1989-1991 and analyzed to determine the squirrel's diet. In spring the squirrel's diet consisted primarily of tree buds, lichens and hypogeous fungi. In fall hypogeous and epigeous fungi and beechnuts were the most common food items. The epigeous fungi were in the families Boletaceae, Strophariaceae and Russulaceae. Hypogeous fungi in the genus Elaphomyces were consumed by 50.8% of the squirrels in the spring and 48.2% in the fall. Five other hypogeous taxa were identified in 5.2% of the samples. All hypogeous species identified in the scats form mycorrhizal relationships with forest All hypogeous species and are dependent scats form mycophagy for spore dispersal. West Virginia northern flying squirrels with forest trees and are dependent on mycophagy for spore dispersal of these mycorrhizal fungi and may contribute to the health of tree species in high elevation red spruce (Picea rubens)/northern flying squirrels facilitate spore dispersal of these mycorrhizal fungi and may contribute to the health of tree species in high elevation red spruce (Picea rubens) /northern hardwood forests in West Virginia.
The West Virginia northern flying squirrel subspecies, Glaucomys sabrinus fuscus, was first described in 1936 from a specimen collected from Cranberry Glades, Pocahontas County, West Virginia (Miller, 1936). At that time there were only two known locations for this subspecies, the type locality and Cheat Bridge, Randolph County, West Virginia.
In 1985 relict populations of Glaucomys sabrinus in the southern Appalachian mountains (G. s. fuscus from West Virginia and Virginia and G. s. coloratus from North Carolina and Tennessee) were listed as federally endangered under the Endangered Species Act of 1973 (Fed. Reg. 50:126). As a result of increased search efforts subsequent to the listing, by 30 June 1999, 876 squirrels had been captured in high elevation forests in six West Virginia counties including Greenbrier, Pendleton, Pocahontas, Randolph, Tucker and Webster (Stihler and Wallace, 1999). Most capture sites were in red spruce (Picea rubens) or red spruce/northern hardwood forests (Stihler et al., 1995).
The diet of the northern flying squirrel has been extensively studied in northwestern North America (McKeever, 1960; Maser et al., 1978; Maser et al., 1986; McIntire and Carey, 1989; Hall, 1991; Rosentreter et al., 1997). Maser's work focused on fungi in the northern flying squirrel's diet whereas Hall, McKeever and Rosentreter looked at all food items. These researchers concluded that lichens and fungi constituted the majority of the items in the flying squirrel's diet in the northwest. Hall detected trace amounts of fir pollen in 56% of Glaucomys sabrinus scat samples from Sagehen Creek, California, but was unable to ascertain whether the squirrels were intentionally consuming fir strobiles or if the pollen was incidentally ingested while foraging for other foods. In northeastern California McKeever found that although seeds from pines and shrubs were available, they were not eaten by the northern flying squirrels. McIntire and Carey reported fungi (11 hypogeous genera as well as unidentified spores), plant tissue, pollen and other unidentified fragments. Their scat samples were collected from northern flying squirrels from Coos County, Oregon.
In the eastern United States Weigl (1968) reported finding staminate fir cones, unidentified fungi, pleurococcus alga and finely chewed buds in the stomachs of seven Glaucomys s. coloratus from North Carolina. In studies of G. sabrinus macrotis in Wisconsin, Jackson (1961) found evidence of various dietary items including hazelnuts, beechnuts, seeds of spruce, balsam fir and maple, wild fruits, fungi, buds of trees, insects, young birds and raw meat. …