Landscape composition and configuration influences woodland caribou calf recruitment

Newfoundland woodland caribou (Rangifer tarandus caribou ) populations are in steep decline and disturbance-related habitat loss and fragmentation have been blamed for similar woodland caribou population declines across the country. Research has focused on caribou habitat selection, and there is a need for studies to focus on landscape components that can be managed, and their relationships with caribou vital rates. I quantified landscape composition and configuration within the calving/post-calving range (CPCR) of female woodland caribou belonging to six herds in Newfoundland to explore their influence on calf recruitment over four years. I identified the CPCR of radio-collared female caribou and calculated the total disturbance area (area of forest fires and area within 250m of human disturbance sources), area occupied by natural landcover types, and three fragmentation measures (effective mesh size, edge to area ratio, and fragmentation extent) for each female's CPCR, and averaging them yearly for each herd. Total disturbance area and the area occupied by mixed forests were found to have negative effects on calf recruitment, whereas no significant direct relationship was found between either of the fragmentation measures and calf recruitment. Using Information Theoretic Approach, I found that the most parsimonious model to explain variation in calf recruitment included total disturbance area, the area occupied by mixed forests and wetlands, and the edge to area ratio measure of fragmentation. The effect of total disturbance area was negative, while the effect of wetlands was positive. It appears that combining quantitative measures of disturbance-related landscape structure (i.e. composition as well as configuration) to explain variation in woodland caribou calf recruitment, or other vital rates, would improve our ability to relate scientific research findings to wildlife management and land-use issues