DOI: 10.5063/aa/nrs.697.1
title: The Ecology of the Pine Marten (Martes americana) at Sagehen Creek, California

description: DOCTORATE DISSERTATION: A study of the ecology of the pine marten (Martes americana) was conducted at Sagehen Creek, California from June 1981 through September 1983 Eleven marten were live-trapped and fitted with radio collars These data were used to investigate movement patterns, den use, and habitat preferences When all data were considered, an activity peak in the early afternoon hours was observed. Males were more active than females at night. Marten were more active during the day in the snow-free season than they were during winter, but generally engaged in the same level of nocturnal activity year-round. The average home range size was 1.39km square for males and 1.02km square for females. Extensive intra and intersexual overlap of home ranges was observed. Trees, snags, stumps and logs provided 77 percent of 210 marten dens located. Comparison with availability data indicated that snags, stumps and logs were preferentially selected as resting sites, but trees were underused in proportion to their availability. Stumps were used more often in summer. Snags and logs were used more in winter than in summer. Den re-use was usually by the same marten first occupying the den, but in 4 instances a different individual used the den. Habitat was characterized and track plate surveys were completed... Thirty-five of 80 stations had marten visitation rates of over 40 percent The presence of red fir (Abies magnifica), the absence of Jeffrey pine (Pinus jeffreyi), low solar incidence, and low snag density all contributed to higher marten visitation rates in the model. Discriminant function analysis separating sites used by marten from randomly selected sites developed a model... High basal area, downfall cover, living ground cover and log density characterized marten habitat Data from the upper and lower Sagehen Creek basin areas were then analyzed separately. Higher basal area, downfall cover, and stump density characterized marten habitat in the upper basin. Higher basal area and downfall cover also characterized marten habitat in the lower basin, as did higher log density and lower percentage of litter ground cover. Shrub-regeneration cover was similar between active marten sites and random sites, but higher on marten rest sites Prey availability by habitat type was investigated by trapping small mammals Highest levels of deer mice populations were consistently found in brushfield habitat. Within forested habitats, highest levels of deer mice populations occurred in logged red fir forest and lodgepole pine forest. Chipmunks were evenly available throughout all habitat types. Mixed conifer forest had the highest number of ground squirrels in 3 of 4 trapping sessions. Montane voles were most abundant in large meadows and lodgepole pine forest. Mountain phenacomys were trapped in logged red fir forest, uncut mixed fir forest, and mixed conifer forest. Audio censuses of chickarees were conducted along small mammal trap lines Chickarees were evenly available in all forested habitats in 4 of 5 censuses. One hundred marten scats were collected. The most common small mammal prey items, measured by percent frequency of occurrence in scats, were montane vole (10.6), chickaree (6.8), and chipmunk (5.8). Summer and winter diets of marten varied only slightly. Chickarees and chipmunks were similarly abundant in habitat preferred by marten and habitat not used by marten. Voles were not abundant in forested habitat, but occurred in relatively high numbers in meadows found within the forested areas frequented by marten. The smallest unit of marten habitat that should be considered by land use planners is 15km squared. Prime marten habitat is found in mature forests dominated by red fir, a mixture of red fir and white fir, and lodgepole pine with a total basal area of 30-60 m squared/ ha. Xeric, mixed conifer forests, especially forest dominated by Jeffrey pine, will not support marten. Downfall cover of 10-20 percent, stump densities of 50-90/ha, and log densities of 20-50/ha contribute to optimal marten habitat within the preferred forest types. Partial timber harvest in the form of selective cutting or small clear-cuts less than 1 ha might increase the suitability of an area for marten by providing more downfall cover in the form of large diameter slash and higher densities of stumps and logs if the site was not burned or intensively prepared for artificial regeneration. Small-area harvest may improve marten habitat, but the immediate effects of logging on marten are unknown. Radio-tagged marten should be monitored throughout the life of a timber sale to evaluate the immediate effects of logging.