Population and habitat assessments for conservation: Comparing national strategies for Canadian boreal caribou and Norwegian wild reindeer

Habitat loss and fragmentation are major threats to biodiversity. While essential,demographic data alone may be insufficient to rapidly detect habitat-driven populationdeclines and identify efficient management actions. This study explores howconservation strategies can use and integrate demographic and environmentalinformation to detect, monitor and counter population declines. By comparing twoextensive conservation strategies for Rangifer tarandus in Canada and Norway, wedraw key insights for more comprehensive and actionable strategies.Conservation strategies often use multicriteria approaches combining population andhabitat metrics, but seldom succeed in formally integrating these through a causalunderstanding of habitat-population relationships. The Canadian strategyprobabilistically assesses the viability of boreal caribou populations both through directpopulation modeling, and by statistically linking habitat disturbance to recruitmentthus indirectly capturing habitat-mediated changes in predator-prey dynamics and theirconsequences on caribou vital rates. The Norwegian strategy develops an expertbasedapproach to score the quality of wild reindeer populations by combiningassessments of habitat quality, connectivity, demography, genetics and health. Whilethe Norwegian assessment is more locally anchored and explores a wider range ofdrivers, the Canadian one is more targeted and provides a statistical conversion ratebetween habitat and population metrics. Both assessments serve as a basis for followupmanagement actions.This study highlights the need to intensify research to quantify cumulativeanthropogenic impacts on the loss of functionally connected habitat, and theirconsequences on population viability. This would enable early-warning systems forassessing population declines, and help shape more targeted prevention, mitigationand restoration actions.