SOCIAL SPACING
Pine voles usually have home ranges of about 40-45 square meters (Whitaker & Hamilton; 1998). As far as our class's definition of a classical territory as being a defended resource and exclusive territory, it would be a weak argument to call the burrow systems a territory. Burrow systems are exclusive to colonies, but territorial defense is not an issue. Pine voles avoid invading other colonies (Lapasha & Powell; 1994). Food is superabundant since pine voles feed on such a wide variety of things; therefore the food source is not really an economically defensible resource. For this reason, protecting a territory would waste energy. It makes the most sense to define pine vole social spacing as a home range.

Presence of neighboring colonies limits the home range size, location, and dispersal of pine vole colonies (Lapasha & Powell). Pine voles will take over neighboring empty and intact burrow systems that are available because it increases the home range and availability of food supply with little extra energy cost and can still avoid surface predation. However, burrow systems are a limited resource and do limit pine vole populations (Lapasha & Powell). Authors have suggested that pine vole home range dispersal depends on the spatial equilibrium of colonies in the summer and that winter may be an "off-season" for this invasion trend (Lapasha & Powell).

Pine Vole Tunnel Opening- Permission to display picture for educational use from the USDA. Picture can be found displayed by the Home and Garden Information Center.