USGS Occupancy Surveys for Dixie Valley Toads, Anaxyrus williamsi, in Churchill County, Nevada from April 2018 to May 2021

Desert spring wetlands host many endemic species that require aquatic habitat and are isolated by the surrounding xeric terrestrial habitat. The Dixie Valley Toad (Anaxyrus williamsi) is a recently described anuran species endemic to desert spring wetlands in the Dixie Valley, Churchill County, Nevada, USA. Given this species was only recently recognized as distinct from Anaxyrus boreas, little is known about its ecology and habitat requirements. These data represent the results of surveys for Dixie Valley Toads conducted from April 2018 to May 2021 in Churchill County, Nevada, USA and associated covariates from surveys and study sites. The potential wetland habitat for the Dixie Valley Toad was divided into 20 meter by 20 meter cells, and 60 cells were selected for sampling using a Generalized Random Tessellation Stratified design. The data were collected following an occupancy study design, with repeated (secondary) surveys of each cell during each primary period (6 total periods). For each cell in each survey, the detection or nondetection of adult and larval Dixie Valley Toads was recorded. Adult Dixie Valley Toads were detected in 75 percent of cells during at least one survey, and larval Dixie Valley Toads were detected in 20 percent of cells during at least one survey. Data on water temperature, air temperature, percent of the cell with surface water, water depth, and emergent vegetation cover were also recorded during surveys.

These data support the following publication:
Rose, J.P., Kleeman, P.M., and Halstead, B.J., In Review. Hot, wet, and rare: modeling the occupancy dynamics of the narrowly distributed Dixie Valley Toad.