Incilius alvarius Sonoran Desert Toad
Some other names for this species:
Colorado Desert Toad
The genus Incilius was split from Bufo by Frost et al in 2006. This split is particularly controversial among herpetologists, and many references still use the long-established Bufo. Also, Ollotis was used by some references between 2006 and 2009.
Pima County, ArizonaAugust 9, 2009
Sonoran Desert Toad (Incilius alvarius)
These huge toads are common at night in southern Arizona during the monsoon season, when the humidity is high and thunderstorms occur almost daily. Or at least, that's what the weather is supposed to do. When I visited for about a week at the height of the traditional monsoon season, there were only two days with any precipitation at all, and this was not one of them. Apparently some of the toads were getting desperate and hopping around anyway. The dry dirt on this one's back shows that the recent weather had not been toad-friendly.
Pima County, ArizonaAugust 19, 2013
Sonoran Desert Toad (Incilius alvarius)
Four years later, in the same area, I visited when there was a little more precipitation, and a lot more toads.
Organ Pipe National Monument, Pima County, ArizonaAugust 2, 2014
Sonoran Desert Toad (Incilius alvarius) Sonoran Desert Toad (Incilius alvarius)
Some day I will get photos of Sonoran Desert Toads that aren't sitting in the middle of the road at night, but today was not that day.
near Animas, Hidalgo County, New MexicoAugust 22, 2016
Sonoran Desert Toad (Incilius alvarius)
These big guys are much harder to photograph than the numerous smaller toads on hot summer nights in this area, because they never want to stop hopping away from you (albeit slowly), no matter how you reposition yourself.
Printed references: