Diet, nutrition and fitness of Scandinavian moose in a changing climate
Annika Maria Felton1
Sveriges lantbruksuniversitet, Southern Swedish Forest Research Centre, SLU, Box 190, SE
Abstract Performance indicators of moose populations in Sweden are in decline, for example calf weights and recruitment. Understandably, questions are being raised regarding the potential drivers, such as forage availability and climate change. In this talk I will summarize our efforts to decipher interactions between forest management, moose foraging choices and fitness, as well as the potential response of moose populations to a changing climate. I will summarise findings from several studies from Scandinavia in which we have studied moose foraging behaviour and identified links between their diets, nutritional intake and fitness. This research highlights for example the value for moose of diverse diets rich in broadleaf trees, and the ecological costs of intensive production forestry, particularly to the ericaceous dwarf shrubs, which are a staple food for moose in this region. I will also convey our findings from a systematic view in which we evaluated the direct effects of temperature, rainfall, and snow on all cervid species inhabiting boreal and temperate regions of the northern hemisphere. Our synthesis indicates that, depending on the local context, pros and cons for cervids of a warmer climate may cancel each other out, or lean towards the negative. For example, while moose populations will likely benefit from less snow during winters, hotter and drier summers may exceed their physiological tolerances, potentially causing northwards shifts in distributional ranges. As our knowledge increases regarding the relationships between moose diets, nutrition and fitness, we will be better equipped to project future consequences of climate change on this iconic species and to what extent management can be adjusted for their benefit.