Table 1.

Examples of longitudinal and/or experimental studies of infectious disease in free-ranging ungulates.

Species	Geographic location	Type of study	Major finding	Implication	Reference
Reindeer (Rangifer tarandus platyrhynchus)	Svalbard, Norway	Experimental and longitudinal	Anthelminthic treatment of the parasite Ostertagia gruehneri increased female fecundity but not overwinter survival. Parasite abundance was positively associated with the magnitude of the fecundity effect	Demonstrates that density- dependent parasite- mediated reduction in host fecundity is a plausible mechanism of host population regulation	Albon et al. (2002)
Soay sheep (Ovis aries)	St. Kilda, Scotland, United Kingdom	Longitudinal	Individuals with the higher antibody levels were more likely to survive harsh winters, but higher antibody levels were associated with reduced fecundity	Highlights the role of environmental variability as a mechanism maintaining immunoheterogeneity	Graham et al. (2010)
African buffalo (Syncerus caffer)	Hluhluwe- iMfolozi Park, South Africa	Experimental	Anthelminthic treatment of gastrointestinal nematode parasites increased circulating levels of interferon gamma, a molecule involved in the immune defense against microparasites	Suggests that immunological trade-offs described in humans occur in wild mammals and have the potential to influence disease dynamics	Ezenwa et al. (2010)
Bighorn sheep (Ovis canadensis)	Idaho, United States	Longitudinal	Among adult females, previous exposure to pneumonia was associated with a decrease in the risk of future disease-related mortality; however, a lamb’s risk of dying was positively associated with its mother’s previous exposures	Uses individual-based data to reconstruct how hosts respond immunologically to an unknown causative agent	Plowright et al. (2013)