Fate of the Caribou: from local knowledge to range-wide dynamics in the changing Arctic

Navigating the New Arctic (NNA) is one of NSF's 10 Big Ideas. NNA projects address converging scientific challenges in the rapidly changing Arctic. This Arctic research is needed to inform the economy, security and resilience of the Nation, the larger region and the globe. NNA empowers new research partnerships from local to international scales, diversifies the next generation of Arctic researchers, enhances efforts in formal and informal education, and integrates the co-production of knowledge where appropriate. This award fulfills part of that aim by addressing interactions among the natural environment and built environment in the following NNA focus areas: Arctic Residents, Data and Observation, Forecasting, and Global Impact.

The caribou (Rangifer tarandus) is the most abundant large animal in the Arctic. Caribou have significant influences on social and natural systems. These animals perform the longest terrestrial migrations on Earth in herds of up to half a million individuals. Caribou are central to the spiritual and material culture of Indigenous peoples across the North. In many communities, food security depends directly on caribou presence. Caribou are also an important part of Arctic ecosystems through their impact on forest and tundra. It is therefore extremely concerning that global caribou numbers have declined over recent decades, with some herds collapsing by over 95% since 1990. These declines are likely related to the many environmental changes occurring in the Arctic, but the true causes are unknown. This research follows the leadership of Indigenous communities and other stakeholders to directly address the future of caribou across northern Alaska and Canada. The project trains students and postdoctoral fellows at several U.S. universities, contributing to a strong STEM workforce. Results are disseminated broadly, and data are accessible to the public, including valuable new spatial data products and visualizations. Understanding caribou decline is one of the most pressing concerns in the Arctic, and this project provides data to inform decision-making on the management of a vital resource.

This project tests hypotheses that relate specific climatic and ecological relationships to the movements of populations of migratory caribou. The hypotheses are directly informed by local observations and the immediate concerns of affected communities. Several relevant changes in Arctic environments include: shifts in the composition of tundra vegetation, reduction in snow quality and quantity, changes to fire regimes, increased insect harassment, and impacts of built environments. The analyses use an unprecedented compilation of caribou monitoring and satellite collar tracking data amassed by partners in territorial and federal agencies across northern Alaska and Canada, combined with Indigenous Knowledge and remote sensing of vegetation, fire, snow, and land-cover. Strong, well-established relationships with Arctic community partners, including Indigenous-led co-management governance boards and government agencies, enable a broad knowledge base. By leveraging an enormous collaborative network, it is possible to compare and contrast caribou populations, highlighting both fundamental processes and local particularities of relevant interactions. The ultimate outcome will be the ability to generally anticipate the fate of caribou as the Arctic continues to change.