What’s Eating You, Caribou? Investigating the Gastrointestinal Parasites of West Greenland Caribou

Austmannadalen – Greenland

Caribou and reindeer (Rangifer tarandus spp.) are a key component of many Arctic ecosystems and are an important resource for northern communities. Gastrointestinal parasites, like roundworms (Nematoda) and tapeworms (Cestoda), are common in these animals, but we know little about the true diversity present and how they might be affecting caribou health.

During the International Polar Year (2007-2009) researchers with the CARMA (CircumArctic Rangifer Monitoring and Assessment) Network undertook extensive sampling of several Rangifer herds in order to assess animal and population health and to begin exploring some of these questions.

Jillian Steele examining caribou samples under microscope

In 2009, Jillian Steele, a Masters student with the CCWHC at the University of Calgary, analyzed the gastrointestinal parasites of these animals in detail, including how they might be affecting caribou health. Her work on the two largest caribou populations in west Greenland, done in collaboration with the Greenland Institute of Nature, demonstrated that these two neighbouring and closely related populations had different gastrointestinal parasites. Interestingly, it appears that human mediated animal movements over the past century, specifically the introduction of reindeer from Norway and muskoxen from eastern Greenland, have been major factors determining the gastrointestinal fauna of the caribou. The findings from Jillian’s research are already influencing management decisions in Greenland. In particular her results highlight the importance of defining the pathogen diversity in wildlife populations, even those that are closely related genetically or geographically, prior to anthropogenic mixing of populations (e.g., reintroductions and translocations), in order to avoid unintended consequences of such movements.

Jillian’s work also found that even low intensities of parasite infection may be influencing caribou health and that these effects may differ depending on the species of nematodes present, again emphasizing the importance of defining biodiversity of gastrointestinal parasites in order to understand the potential impacts on wildlife populations.