Back to search results

April Animal Determinants of Emerging Disease Rounds - Parasitic Infection in a Social Carnivore: T. gondii Exposure Increases Risky Decision Making in Gray Wolves


Speaker: Connor Meyer, PhD Candidate from the University of Montana.

Overview: Toxoplasma gondii is a protozoan parasite capable of infecting any warm-blooded species yet, requires a feline definitive host to sexually reproduce. Experimental studies indicate that T. gondii infection increases an individual’s risky decision-making but, due to the intensive data collection and large samples sizes necessary, T. gondii’s role in ecosystem processes is understudied. We sought to understand the role in which T. gondii exposure affects gray wolf decision-making in Yellowstone National Park. To achieve this, we used 25 years of wolf serological and behavioral data, and 14 years of cougar serology and space use data, to test for a) what affected wolf exposure to T. gondii and b) if there was a change in behavior of gray wolves after exposure. We examined the effect of toxoplasmosis on four behaviors associated with risk taking: (1) dispersal, (2) achieving dominant social status (i.e., becoming pack leader), (3) approaching people or vehicles (i.e., habituation), and (4) dying of a specific cause, measured two ways: intraspecific mortality or anthropogenic mortality. We demonstrate that T. gondii infection directly affected the probability that a wolf became a pack leader or dispersed by 46 and 11 times, respectively, compared to seronegative wolves."