Southern Toad
Bd-naïve toads did not avoid of any of the treatments (Treatment:df = 4, χ2 = 2.00, P = 0.736; Fig. 2C). There was a significant effect of treatment on the avoidance behavior of Bd-experienced toads (Treatment: df = 4, χ2 = 2.40, P = 0.018, Fig. 2D) but they did not avoid all treatments equally. Regardless of whether toads were Bd-naïve or Bd-experienced, toads showed no significant differential avoidance of treatments with or without zoospores (Zoospores: df = 1, χ2 = 0.11, P = 0.742; Zoospores*experience: df = 1, χ2 = 0.12, P = 0.729; Fig. 4A) or with or without live zoospores (Live zoospores: df = 1, χ2 = 0.03, P = 0.854; Live zoospores*experience: df = 1, χ2 = 0.33,P = 0.568; Figs. 2D, 4B). However, avoidance of Bd metabolites was significantly greater when toads were Bd-experienced than Bd-naïve (Metabolite*experience: df = 1, χ2 = 5.89,P = 0.015; Figs. 4C, 5), suggesting that the metabolites that contain enzymes that digest amphibian skin trigger a learned avoidance response. To better estimate the magnitude of learned avoidance of treatments with metabolites, we compared treatments with metabolites to only the controls (rather than all treatments without metabolites). In these analyses, the difference between avoidance when experienced and naïve was even stronger than in the previous analyses (Metabolite*experience: df = 1, χ2 = 7.76,P = 0.005). Toad responses to the three treatments containing metabolites did not differ significantly when naïve or experienced (Treatment: df = 2, χ2 = 1.06, P = 0.589; Treatment*experience: df = 2, χ2 = 1.69,P = 0.430), indicating that the overall learned avoidance of metabolites was not a function of just one of these three metabolites-containing treatments.