World Wide Web

Ecology

Biology

Social psychology

Parasite hosting

Computer science

Genetics

Psychology

Biological evolution

Protozoan parasite

Boldness

Zoology

Hyena

Host (biology)

Genetic Fitness

Personality

Antibody

Toxoplasma gondii

Nature Communications

Toxoplasma gondii is hypothesized to manipulate the behavior of warm-blooded hosts to promote trophic transmission into the parasite’s definitive feline hosts. A key prediction of this hypothesis is that T. gondii infections of non-feline hosts are associated with costly behavior toward T. gondii ’s definitive hosts; however, this effect has not been documented in any of the parasite’s diverse wild hosts during naturally occurring interactions with felines. Here, three decades of field observations reveal that T. gondii -infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. We discuss these results in light of 1) the possibility that hyena boldness represents an extended phenotype of the parasite, and 2) alternative scenarios in which T. gondii has not undergone selection to manipulate behavior in host hyenas. Both cases remain plausible and have important ramifications for T. gondii’ s impacts on host behavior and fitness in the wild.

Toxoplasma gondii infections are associated with costly boldness toward felids in a wild host