Multi-scalar Responses of Forest Carnivores to Habitat and Spatial Pattern: Case Studies with Canada Lynx and American Martens

• Main Author: Fuller, Angela K.
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2006
• Subjects: American marten; Martes americana; Canadian Lynx; Lynx canadensis; Animal Sciences; Natural Resources and Conservation; Terrestrial and Aquatic Ecology; Newfoundland; Lynx
• Online Access: https://digitalcommons.library.umaine.edu/etd/1530; https://digitalcommons.library.umaine.edu/context/etd/article/2559/viewcontent/FullerAK2006.pdf

I examined responses of Canada lynx (Lynx canadensis) and American martens (Martes americana) to habitat features at multiple spatial scales. At the stand-scale, lynx (n = 6) selected tall regenerating clearcuts (4.4-7.3 m, 11-26 years post-harvest) and established partially harvested stands (1 1-21 years post-harvest) and they selected against short regenerating clearcuts (3.4-4.3 m, 11-26 years), recent partially harvested stands (I- 10 years), and mature stands (>40 years). The highest fractal dimension of foraging paths was in tall regenerating clearcuts and established partially harvested stands, which were stands that provided intermediate to high snowshoe hare (Lepus nmericanus) density, intermediate cover for hares, and intermediate levels of canopy closure and live-tree basal area. Movement paths of lynx had increasing fractal dimension at smaller scales and were straighter than they were at broader spatial scales, suggesting that lynx were trying to avoid switching from highly preferred to lesser preferred stands. Lynx maximized time in areas with high-intermediate hare densities to facilitate increased capture success of snowshoe hares, supporting the hypothesis that lynx select for prey access over prey density. I developed models incorporating landscape composition and configuration to predict occurrence of home ranges (n = 63) for American martens in Newfoundland and to evaluate the relative influences of habitat loss versus fragmentation on this endangered subspecies. Habitat loss was the primary determinant of occupancy of landscapes by martens. The probability of occupancy declined precipitously as the percent of suitable habitat fell below 60% of home-range sized landscapes; therefore, efforts to recover marten populations should focus on maintaining suitable habitat above 60%. I also compared threshold responses in occupancy of martens to the amount of suitable habitat in the landscape between two geographically isolated subspecies (Martes americana americuna in Maine and Martes americana ...