Parasitic infection increases risk-taking in a social, intermediate host carnivore.
Level 5 - mechanism / opinion, no new human data
Animal research (Level 5 by CEBM rules; Level 3 by design analogy for a longitudinal cohort study).
PubMed 36424436 · doi:10.1038/s42003-022-04122-0
What was done
Analyzed 26 years of longitudinal spatial, serological, and behavioral monitoring data from wild gray wolves (*Canis lupus*) in Yellowstone National Park, USA. The researchers evaluated territory overlap with cougars (*Puma concolor*, the definitive host) as a predictor of *Toxoplasma gondii* seroprevalence and tested associations between seropositivity and risky behaviors, specifically dispersal and pack leadership.
What was found
The abstract reports directional outcomes without numerical values, effect sizes, or confidence intervals. Wolves with territory overlap in high-density cougar areas had higher odds of infection. In addition, seropositive wolves were more likely to disperse from their natal packs and more likely to become pack leaders.
Why it matters
Provides rare longitudinal field evidence that parasite-induced behavioral manipulation occurs in wild intermediate host carnivores. These individual behavioral changes may scale up through social structures to alter pack leadership, population-level dynamics, and multi-species transmission loops.
Limits
The abstract provides no sample sizes (n = ?), quantitative metrics, or effect estimates. Being an observational wildlife study, unmeasured behavioral or genetic confounders could influence both exposure risk and bold behaviors, preventing definitive causal inference.
Cited by
- supports Most pack leaders among wolves in Yellowstone National Park are infected with Toxoplasma gondii.