Effects of urbanization on the occurrence of Batrachochytrium dendrobatidis: do urban environments provide refuge from the amphibian chytrid fungus?

Abstract

Batrachochytrium dendrobatidis (Bd) is a widespread pathogenic fungus that is known to cause the disease, chytridiomycosis, which can be lethal to many amphibians. We compared occurrence rates on spring peepers (Pseudacris crucifer) in urban and forested breeding sites in eastern Texas, USA. All study sites were at approximately the same latitude and altitude, and samples were collected at the same time of year to isolate differences in Bd infection rates between habitat types. We found significant differences (p < 0.001) in the occurrence of Bd between habitats; with dramatically lower rates of occurrence at urban sites (19.5 %), compared to forested sites (62.9 %). The exact reason for the observed differences in the occurrence of Bd is not known, however, we suspect that warmer temperatures or lower population densities and lower species richness at urban sites all could play a role in our results. Our findings suggest that urban environments may provide a refuge for some amphibians from the pathogen.