Macronutrient balancing in Northern cervids

Macronutrient Balancing in Northern Cervids: understanding diets for sustainably managing ungulates and their impacts

Swedish ungulate management faces an enormous complexity challenge: multiple ungulate species increasingly interact over plant resources that they share with a variety of human stakeholders e.g. in agriculture and forestry. Large-scale processes, like the transformation of landscapes and climate change, further increase this complexity. The question of how to manage this system to allow for healthy, sustainable, populations of all ungulate species, while minimizing their negative impacts on human society is therefore at the center of wildlife management. The key to answering this question lies in an improved understanding of ungulate nutritional ecology; i.e., what do ungulates eat and why? The drivers of food choices, however, are multiple and complex. There is increasing evidence that classic hypotheses like maximization or limitation of individual nutrients, and measures of botanical diet diversity are limited in their explanatory power and that a better understanding can be obtained from the rules of macronutrient (protein, carbohydrates, and fat) balancing. Here, we combine a dataset of >3000 individual diets of moose, red deer, roe and fallow deer, with the nutritional composition of their ingested forage items. We will apply the Nutrition Geometric Framework to investigate patterns and drivers of macronutrient balancing in wild ungulates across different seasons and sites in Sweden. This approach places our current knowledge about species interactions and niche overlap into a new and more predictive framework regarding challenges like browsing and crop damage. It leads to a better understanding of what constitutes suitable foodscapes and how these can be created through long-term strategies like silviculture and landscape design but also short-term actions like supplementary feeding. Our project will generate understanding and suggest management solutions for actors involved in wildlife management, forestry and agriculture simultaneously.

Robert Spitzer, Swedish University of Agricultural Sciences

2 980 000 SEK