Disease hotspots or hot species? Infection dynamics in multi-host metacommunities controlled by species identity, not source location

Pathogen persistence in host communities is influenced by processes
operating at the individual host to landscape-level scale, but isolating
the relative contributions of these processes is challenging. We developed
theory to partition the influence of host species, habitat patches, and
landscape connectivity on pathogen persistence within metacommunities of
hosts and pathogens. We used this framework to quantify the contributions
of host species composition and habitat patch identity on the persistence
of an amphibian pathogen across the landscape. By sampling over 11,000
hosts of six amphibian species, we found that a single host species could
maintain the pathogen in 91% of observed metacommunities. Moreover, this
dominant maintenance species contributed, on average, twice as much to
landscape-level pathogen persistence compared to the most influential
source patch in a metacommunity. Our analysis demonstrates substantial
inequality in how species and patches contribute to pathogen persistence,
with important implications for targeted disease management.