Effectiveness of above-ground pipeline mitigation for moose (Alces alces) and other large mammals

Above-ground pipelines for in situ oil sands development are potentially significant vectors of habitat fragmentation for large mammals. We evaluated the use of elevated pipeline clearances (distance between the ground and the bottom of the pipeline) and pipeline crossing structures, the two primary methods of mitigating the barrier effect of above-ground pipelines on large mammals, with a particular emphasis on moose (Alces alces), in northern Alberta, Canada. Winter snow tracking and remote cameras were employed for one year to monitor large mammal interactions with a 5.5 km stretch of pipeline mitigated with five pipeline crossing structures and a 1.6 km control area of unmitigated pipeline. A minimum threshold pipeline clearance of 140 cm was critical in allowing adult moose to cross underneath the pipeline. Pipeline crossing structures facilitated movement across the pipeline and were used more than sections of elevated pipelines by all species.