Incilius mazatlanensis Sinaloa Toad
near San Javier, Sonora, MexicoAugust 19, 2017
Sinaloa Toad (Incilius mazatlanensis) Sinaloa Toad (Incilius mazatlanensis) Sinaloa Toad (Incilius mazatlanensis)
We drove highway 16 from Hermosillo up into the Sierra Madre, crossing a variety of habitats, hoping to see some new and interesting critters. Just as it started to get dark, we saw a toad on the road and stopped to photograph it. Over the next half an hour or so we saw dozens and dozens more. Then they stopped appearing, and I don't think we saw another one the entire evening.

The three pictured here are in order of increasing size and age. As they get older, the ridges on their head and face become more and more defined and more and more black.

And yes, that biggest one decided to empty its bladder just before I got a photo.

Online references:
Printed references: