How does the reindeer’s diet change between summer and winter?

The reindeer’s diet undergoes a significant seasonal shift to adapt to the harsh Arctic environment.

During the summer, reindeer consume a varied diet consisting of grass, sedges, green leaves from shrubs, and the new growth of trees such as larch, willow, and birch. In late summer, they also actively seek out mushrooms.1

As winter approaches, their metabolism slows, and they transition to a diet primarily composed of high-carbohydrate lichens known as reindeer moss. To access these lichens, reindeer use their front feet to dig craters through the snow, sometimes reaching depths of up to 60 cm (2 feet). Because this winter diet is low in protein, reindeer have evolved to survive by recycling urea within their digestive systems to utilize its nitrogen.12