Mapping Caribou Forage Resources in Ontario

February 28, 2025

 Over the past two decades, research has revealed just how crucial nutrition, particularly during summer, is for shaping dynamics of large ungulate populations in various regions of North America. In 2009, NCASI launched an innovative research program to explore how nutritional resources influence caribou populations and how forest management can be used to influence these resources.

Using a novel approach, NCASI researchers deployed captive, trained lactating caribou and their calves in temporary, electrified pens set within native habitats. This method allowed us to evaluate the relationships between fine-scale forage attributes (e.g., forage abundance, composition, and quality) and caribou foraging dynamics and nutrition (e.g., dietary preferences, the digestible energy and protein content of diets and most importantly, forage and nutrient intake rate).

The insights gained went well beyond traditional forage surveys by providing direct estimates of the nutrition caribou actually obtain from their environment.

In 2024, NCASI applied its findings across eight boreal caribou ranges in northern Ontario, extending west to east from Berens to Kesagami. Our work delivered:

  • Foodscape Maps: Spatially explicit maps of nutritional resources
  • Habitat Use Map: A tool that predicts probability of selection for adult female caribou relative to nutrition resources and predation risk;
  • Nutritional Implication Map: A user-friendly tool rating each pixel according to:
    • Nutritional adequacy for lactating females and their calves during summer;
    • Response to stand-replacing disturbance;
    • The likelihood that forage resources could benefit moose and thus be potentially detrimental to caribou;
  • Field Guide: An accessible resource to interpret and utilize these innovative products

Overall, these products offer the Ontario government and land managers a robust landscape planning tool – helping to forecast how forage, caribou nutrition, and habitat use might shift over time due to forest management actions and natural disturbance, and ultimately guiding strategic decisions to enhance caribou forage across northern Ontario.