Repeated surveys of pond-breeding amphibians in northern idaho and northeastern washington, usa

Landscape-level occurrence and trend data are needed for effective amphibian conservation and substantial data gaps exist for pond-breeding amphibians in the Idaho Panhandle and northeastern Washington, USA. In 2018 and 2019 we conducted dip-net surveys for pond-breeding amphibians across a 21,775 km(2) study area at 124 ponds which we first surveyed five years earlier in 2013 and 2014. We documented changes in the number of sites where we observed breeding activity for each sampling session of Long-toed Salamanders (Ambystoma macrodactylum; from 51 to 52), Columbia Spotted Frogs (Rana luteiventris; from 48 to 59), Sierran Tree Frogs (Hyliola sierra; from 12 to 15), and Western Toads (Anaxyrus boreas; from 16 to 8). We detected no change in number of non-native American Bullfrog (Lithobates catesbeianus) breeding sites (n = 5 both surveys) although finer scale surveys have documented an American Bullfrog expansion in the northern portion of our study area. Our data concur with current conservation assessments of Long-toed Salamanders, Columbia Spotted Frogs, and Sierran Tree Frogs which are not currently considered at risk species in our study area. Our data also concur with the current conservation assessments of Western Toads as a Species of Greatest Conservation Need in Idaho and Washington. During the second sampling session, we detected Western Toad breeding activity at only 50% of sites (n = 8) of which they were detected during the first sampling session (n = 16). During both surveys, the majority (n = 14, 77%) of Western Toad breeding detections occurred in the relatively cooler northwestern portion of the study area. We present these results as a second data point for long-term amphibian monitoring in our study area.