How does snow influence where tundra animals find food in winter?

In the tundra, snow acts as a critical environmental factor that dictates where animals can forage and how they expend energy during the winter.1

• Large Herbivores: Strong winds redistribute snow, creating drifts in some areas while leaving others exposed. Wind-compacted snow increases in density, which can hinder large herbivores like caribou and musk oxen by making it difficult to dig through to reach vegetation. While reindeer possess specialized hooves and antlers to help them cut through snow to access lichens and plants, the presence of wind-packed snow often limits food availability, forcing these animals to migrate or move across the landscape to find accessible forage.123
• Small Rodents: Conversely, areas with deeper snow cover are essential for small rodents, such as lemmings. These animals remain active throughout the winter, utilizing the insulating layer of snow to construct nests and feed on the roots of grasses and sedges at the ground's surface, protected from the extreme cold and drying conditions above.12