Diet composition in herbivores differs greatly from season to season because they eat many types of grasses, shrubs, and forbs. This flexibility allows arctic-alpine species like mountain hares (Lepus timidus) to cope with changing environmental conditions over the seasons and the corresponding changes in food quantity and quality. Understanding how, when, and why animals use certain areas is critical to their conservation and management.
Rehnus and Bollmann investigated the distribution of pellets and of individual core activity areas of mountain hares in the Swiss Alps and compared differences between spring and autumn. Pellets were collected from 2014 to 2019; individuals were determined using an established, non-invasive genetic technique.
Their study presents details about altitudinal shifts in the feeding sites and activity areas of mountain hares in the Alps. They conclude that the annual “wave” of greening from lower to higher elevations, which correlates with forage availability and quality, explains this shift. However, further research is needed on how these shifts are affected by climate change and how they interact with nutritional needs and thermoregulatory mechanisms.
Reference: Rehnus, M., Bollmann, K. (2020) Mountain hares Lepus timidus follow the green-up wave in the pursuit of high-quality food. Wildlife Biology, 2020, 3: 00720. doi: 10.2981/wlb.00720
You can find the full paper here.
Picture: Mountain hare during grooming in early-summer (photo © Rolf Giger).