Disease in a dynamic landscape: Host behavior and wildfire reduce amphibian chytrid infection

Authors: Blake R Hossack; W H Lowe; J L Ware; P S Corn
Contribution Number: 416



Disturbances are often expected to magnify effects of disease, but these effects may depend on the ecology, behavior, and life history of both hosts and pathogens. In many ecosystems, wildfire is the dominant natural disturbance and thus could directly or indirectly affect dynamics of many diseases. To determine how probability of infection by the aquatic fungus Batrachochytrium dendrobatidis (Bd) varies relative to habitat use by individuals, wildfire, and host characteristics, we sampled 404 boreal toads (Anaxyrus boreas boreas) across Glacier National Park, Montana (USA). Bd causes chytridiomycosis, an emerging infectious disease linked with widespread amphibian declines, including the boreal toad. Probability of infection was similar for females and the combined group of males and juveniles. However, only 9% of terrestrial toads were infected compared to >30% of aquatic toads, and toads captured in recently burned areas were half as likely to be infected as toads in unburned areas. We suspect these large differences in infection reflect habitat choices by individuals that affect pathogen exposure and persistence, especially in burned forests where warm, arid conditions could limit Bd growth. Our results show that natural disturbances such as wildfire and the resulting diverse habitats can influence infection across large landscapes, potentially maintaining local refuges and host behaviors that facilitate evolution of disease resistance.

Publication details
Published Date: 2013
Outlet/Publisher: Biological Conservation 157: 293-299
Media Format: .PDF

ARMI Organizational Units:
Rocky Mountains, Northern - Biology
Climate Change; Disease; Fire; Monitoring and Population Ecology; Species and their Ecology; Stressors
Place Names:
Glacier National Park; Montana
amphibians; Bd; behavior; chytrid fungus; Chytridiomycosis; climate; disease; ecology; fire; habitat effects; pathogen; population; stressors; wetlands; wilderness
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