ECOLOGICAL AND PHYSIOLOGICAL ASPECTS OF A MOOSE POPULATION IN THOMAS BAY, SOUTHEAST ALASKA

Abstract

Ecological studies of moose (Alces alces andersoni) inhabiting the moist temperate Picea sitchensis - Tsuga heterophylla biome of southeast Alaska are lacking. This study reports on field investigations from March, 1978 to January, 1980 of a small moose population in an intensively logged mainland area near Petersburg, Alaska. 5 telemetered female moose were nonmigratory. Summer and winter home ranges averaged 14.1 km² (range 2.2 to 29.6 km², n = 8) and 11.4 km² (range 3.2 to 30.3 km², n = 5), respectively. The maximum observed distance moose moved in a 22 month period averaged 9.3 km (range 4.8 to 18.4 km, n = 5). Vaccinium ovalifolium, Alnus crispa sinuata, Ribes laxiflorum, Salix sitchensis, Populus balsamifera trichocarpa, Cornus canadensis, Dryopteris dilatate, and Athyrim filix-femina were major fall and winter food species as determined from rumen content analysis and browse utilization transects. Moose preferred habitats within 1.6 km of rivers, at elevations under 80 m, and with slopes of less than 30%. Twenty percent of all telemetry locations were in noncommercial riparian vegetation, 1% were in muskegs, and 13% were in muskeg-scrub timber or mixed muskeg-coniferous forest. The remainder of the locations were divided equally between commercial old-growth and 6-to-26-year-old-clearcuts. Seasonal habitat preferences are presented. Moose densities were estimated at 1.6 to 2.3/km². Herd quality appeared poor based on blood chemistry data, a low incidence of twinning, and poor winter calf survival. Low availability of high quality browse during winter is believed to be the major regulating factor on the herd. Some habitat management concerns are described.