Biases in trapping larval amphibians in playa wetlands

Standardized, effective sampling methods are required to monitor amphibian population trends and community composition. Funnel traps have been used to ostensibly estimate species richness arid relative abundance of larval amphibians. We tested whether funnel traps can be used to provide unbiased estimates of amphibian community composition in playa wetlands by comparing seining-dip netting and passive funnel-trapping results. Plains spadefoots (Spea bombifrons) were more prone to be captured in funnel traps whereas New Mexico spadefoots (S. multiplicata) were less likely captured by funnel traps than by seines and dip nets. In playas funnel traps should be used only for collecting specimens and not for estimating amphibian community composition.