Ecology and Vulnerability

Virginia Northern Flying Squirrel

Little research has focused on small mammals of greatest conservation need in the Northeast.

Shifts in Range, Elevation, and Depth

While not specifically about the Virginia Northern Flying Squirrel, the Southern Flying Squirrel (G. volans) has completely displaced the nominate species (G. sabrinus) between 1986 and 2004 in a study area in Maine (Wood et al., 2016) as the Southern Flying Squirrel has expanded its range north. A warming climate appears to be one of many reasons for this displacement. Increased minimum summer temperatures have allowed the pathogenetic nematode (Strongyloides robustus) to become more infectious (Wetzel and Weigl 1994). These nematodes are more virulent in Northern Flying Squirrels than in Southern Flying Squirrels which carry them (Krichbaum et al., 2010; Wood et al., 2016). In Maine, experimental tests and field studies found that high ambient temperatures did not cause the nominate Northern Flying Squirrels heat stress (Gudde, 2022), giving further evidence that a northerly range shift is likely resulting from due to being out-competed by the Southern Flying Squirrel and introduction and higher survival rate of the nematodes it carries. Increasing temperatures at higher elevations will likely have similar effects on the Virginia Northern Flying Squirrels in the isolated, high elevation populations that persist in Virginia and West Virginia as they are forced further up the mountains.

Changes in Population

Warmer spring temps appear to lead to lower female Allegheny Woodrat abundance in West Virginia, but the mechanism is unclear (Manjerovic et al., 2009).

Indirect Effects

As Southern Flying Squirrels continue to move into new areas due to warmer winters, they have been hybridizing with the Northern Flying Squirrels in Pennsylvania (Garroway et al., 2010), which may also become a problem for the Virginia Northern Flying Squirrels. Allegheny Woodrat