Habitat variables influencing breeding effort in northern clade Bufo fowleri: Implications for conservation

Abstract

Local extirpations of the northern clade of Fowler's toad, Bufo fowleri, have been documented in the northeastern United States and Canada. To facilitate conservation of this species, we identified key characteristics of its preferred breeding habitat and adjacent landscape at Cape Cod National Seashore. We conducted calling surveys at 67 wetlands to quantify B. fowleri annual breeding effort over three years. The resultant multivariate models were then tested with data collected at 30 additional wetlands. B. fowleri choruses were more likely to be detected in permanent wetlands than semi-permanent or temporary wetlands. Predaceous fish and Rana catesbeiana did not negatively affect breeding effort. Wetlands used for breeding typically had shallower shores, less emergent vegetation, less canopy cover, fewer organic acids, and were warmer and less acidic than sites with no evidence of breeding choruses. Large choruses of B. fowleri typically occurred in wetlands containing < ∼33% woody emergent vegetation and adjacent uplands had more bare habitat and less development than sites without breeding. Our results suggest that B. fowleri in the northeastern United States will decline as development and post-agrarian reforestation continue and that removal of woody vegetation in and adjacent to breeding ponds may be necessary to maintain some populations.