Winter site occupancy patterns of the northern flying squirrel in boreal mixed-wood forests

We assessed habitat use by the northern flying squirrel (Glaucomys sabrinus) to test the hypothesis that the species is not a late-seral coniferous forest specialist in boreal mixedwood forests of northwestern Québec. We monitored 149 pairs of nest boxes over 3 visits during February–April 2008. A total of 31 pairs of nest boxes were occupied during the study. The average (3.7, 2.8, and 1.8) and maximum (8, 6, and 4) numbers of individuals in nest boxes decreased from the first to last visit. Average air temperatures were below freezing and increased with the arrival of spring (−23.9, −14.5, and −3.7 °C). Using GIS software, we created a 430-m (median dispersal distance) buffer around each pair of nest boxes and extracted landscape composition variables from digital forest inventory maps. We created models that potentially explained site occupancy by the northern flying squirrel as well as detection probability. Model selection indicated that the area of coniferous forests negatively affected site occupancy by flying squirrels while temperature positively influenced detection probability. Our results support the hypothesis that the northern flying squirrel is not a habitat specialist, but can occupy a wider range of forest cover types than previously recognized in various landscape contexts.