Eventually Tim got back in touch with his contact, and discovered that the directions had been misunderstood. We shouldn't have been looking for hunks of concrete; we should have been looking for concrete-lined canals. Aha! Most of the canals were not concrete-lined, but when we found one that was, a couple of gartersnakes were quickly spotted and captured for photos.
These gartersnakes are quite different from your typical gartersnakes. With their extremely aquatic ways and extra-thick bodies, they seem closer to Nerodia watersnakes than Thamnophis, and in fact have been classified that way in the past.
- Heimes, P. 2016. Snakes of Mexico
- Rorabaugh, J.C., Lemos-Espinal, J.A. 2016. A Field Guide to the Amphibians and Reptiles of Sonora, Mexico