Frog Skin Swabs
We collected Bd skin swabs from adult MYLF at all three populations sites (Table 1). We swabbed 10X on the frog’s side, 10X upper arm, 10X lower leg, and between the toes using a cloth-tipped swab (Biomeme Inc. Philadelphia, PA.). We used separate swabs for each side of the frog (i.e. right and left side) for comparison testing (Fig. 2).
All the accessible MYLF populations in YNP were known to be Bd positive. In order to swab potential Bd negative anurans, we opportunistically swabbed four California red-legged frogs (Rana dryatonii ) recently introduced to Yosemite Valley, YNP, and one American bullfrog (Lithobates catesbeianus ) in Catalina Island, Catalina National Park. At the time of swabbing, it was unknown whether the R. draytonii or the L. catesbeianus were Bd positive.
To prevent the spread of disease, we disinfected all field gear (e.g., boots, nets, etc.,) in a 0.016% solution of quaternary ammonia between sample sites (Johnson et al., 2003). We did not enter the water with gear prior to eDNA sample collection.