No records of Sonoran Desert Toads from Nevada?

[Zach Cava]

Just curious if anyone has ever found this species in NV? I know there are specimens documented from CA and AZ very near the border, and it would seem strange that none have ever been found in Nevada.

Thanks,
Zach

[Robert Hansen]

My sense is that their distribution closely tracks the portions of the Sonoran and Colorado deserts where summer monsoonal moisture is substantial with low levels of inter-annual variability. In other words, summer precip levels are high enough to create breeding habitat for a several-week period and consistent enough over time to sustain local populations. Beyond this core monsoonal region are areas that experience less significant monsoonal systems (less precip and less frequent); species like gila monsters occur here in low density (e.g., Clark, Kingston, Providence Mountains of the eastern Mojave). Thus, extreme eastern California (outside of the lower Colorado River) and southern Nevada likely cannot support alvarius.

cheers,

bob