How can extreme weather cause local extinctions of Peary caribou and musk oxen?

In the High Arctic, animal populations such as Peary caribou and musk oxen exist near their biological limits, making them highly vulnerable to environmental instability. Because polar ecosystems lack complexity and stability, they are prone to wide population fluctuations driven by periodic extremes of weather.1

When these animals face severe weather events, the impact can be so significant that they become locally extinct. This process is often exacerbated by the nature of the tundra landscape, where strong winds redistribute and compact snow, potentially hindering the ability of large herbivores to dig through to their food sources. Following a local extinction, the reestablishment of these species is not guaranteed; it may take decades for favorable conditions to allow adjacent populations to expand and recolonize the area.1