MOOSE DISTRIBUTION AND WINTER HABITAT ON THE LOWER NORTH SHORE OF THE ST. LAWRENCE RIVER - QUEBEC

Abstract

This paper presents the results of a 6-year study of the relationship between moose (Alces alces) and their winter habitat in the Romaine River on the Lower North Shore of the St. Lawrence River. Winter surveys, photointerpretation and summer field work carried out as part of an environmental analysis performed prior to the development of a hydroelectric complex have provided valuable information concerning winter habitat use by moose at the northeastern limit of their distribution. A total of 92 yards were observed and the mean number of moose per yard was 1.7. The most striking result is the importance of the main river valley to moose as winter habitat. A total of 75 yards (82%) were located in the main valley. Moose find shelter, better food supplies, and opportunities to move between food and cover patches in large river valleys. This is particularly evident in the case of forested islands and river terraces which are prime winter habitats. Secondary valleys and higher areas showed limited use, despite the apparent presence of abundant food. All yards were located on flat areas or gentle slopes and the great majority (98%) were located in well drained areas. Most yards were characterized by pure or mixed stands of black spruce (Picea mariana) with adjacent patches of white birch (Betula papyrifera), young balsam fir (Abies balsamea) and alder (Alnus spp.). Practically all winter yards (97%) were located at least partially on a southern exposure. It appears that critical limiting factors are climatic in nature (temperature, exposure, snow conditions). The availability of southern exposures could be acting as a selective factor to limit the size of the population at the northern limit of moose distribution. Survivors and breeders would be those that exploit the winter habitat resource is in the valleys of large rivers. The possible role of nutrients in the moose-winter habitat interactions is also discussed.