Wolverine Reproductive Den Habitat in Glacier National Park, Montana

Abstract

Wolverine reproductive dens occur in habitat not easily accessible to humans during the denning period (Feb – May) and can be challenging to find.  As such, few den sites have been precisely described. From 2003 – 2007 we located and documented 14 natal and maternal dens of 3 reproductive female wolverine in Glacier National Park.  Two females were known to have produced young in multiple years, using different den sites each year.  Reproductive dens occurred at an average elevation of 1890m (range: 1805-1999m), on 9° slopes (range: 5-22o), within a variable range of aspects (   =263°), and with an average snow depth of 2.6m (range: 2.4-3.4m). Den structures included downed trees, large boulders, and rock caves associated with alpine cirques, ridges, and cliff bands at, or below, existing tree line.  Distance to occupied human development averaged 6.4km, and distance between denning areas of the same female in different years averaged 5.8 km.  Various climate change models predict less persistent snowpack in many areas of the conterminous United States, with a resultant potential for increased isolation of island populations of wolverines.