An evaluation of anuran monitoring by Iowa Department of Natural Resource volunteers and the spatial scale of habitat use in northwestern Iowa

Abstract

<p>Ongoing, widespread declines in amphibian populations are being monitored with surveys conducted by volunteers in North America. These surveys were designed as tools for land managers to conserve amphibians, but the quality of these data remains to be validated.;General findings of this research indicate that volunteer surveys in northwestern Iowa are precise. Accuracy may be improved with the addition of visual encounter surveys to include species that may not be actively calling at the time of the nocturnal auditory surveys. This is especially true for larger species in the region such as leopard frogs and bullfrogs.;Anurans appear to be affected by the amount of wetlands only at small scales (< 200 meters). Higher percentages of wetlands do not appear to be strongly correlated with increased species richness or abundance, possibly due to the high levels of richness observed in isolated wetlands, which are protected from aquatic predators.</p>