Data from: Host-pathogen metapopulation dynamics suggest high elevation refugia for boreal toads

Emerging infectious diseases are an increasingly common threat to
wildlife. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium
dendrobatidis (Bd), is an emerging infectious disease that has been linked
to amphibian declines around the world. Few studies exist that explore
amphibian-Bd dynamics at the landscape scale, limiting our ability to
identify which factors are associated with variation in population
susceptibility and to develop effective in situ disease management.
Declines of boreal toads (Anaxyrus boreas boreas) in the Southern Rocky
Mountains are largely attributed to chytridiomycosis but variation exists
in local extinction of boreal toads across this metapopulation. Using a
large-scale historic dataset, we explored several potential factors
influencing disease dynamics in the boreal toad-Bd system: geographic
isolation of populations, amphibian community richness, elevational
differences, and habitat permanence. We found evidence that boreal toad
extinction risk was lowest at high elevations where temperatures may be
sub-optimal for Bd growth and where small boreal toad populations may be
below the threshold needed for efficient pathogen transmission. In
addition, boreal toads were more likely to recolonize high elevation sites
after local extinction, again suggesting that high elevations may provide
refuge from disease for boreal toads. We illustrate a modeling framework
that will be useful to natural resource managers striving to make
decisions in amphibian-Bd systems. Our data suggest that in the southern
Rocky Mountains high elevation sites should be prioritized for
conservation initiatives like reintroductions.