In the last few trips in Arizona’s ultra-dry June, the only snakes I’ve seen are very small. There are many tiny snakes that make a living eating termites, scorpions, spiders, and other soft-bodied invertebrates, and do not get much more than a foot long. There are also those snakes that feed upon these snakes, they themselves never acheiving a great size.
This one may be one of the smallest, the slightly venomous Smith’s Blackheaded Snake, Tantilla hobartsmithi. This is the first of this species I have seen, despite them being very common. This is most likely due to their tiny size. This adult was around 7 inches long, with a maximum size of around 12 inches.
Another small snake is the common Groundsnake, Sonora semiannulata. I get quite a few emails asking me about the identity of a “baby snake” found in a garage or under a yard rock. Commonly found in and around homes in the Phoenix area, they eat scorpions and spiders, including potentially dangerous bark scorpions and black widows. One of these in your yard is a good thing.
A snake that eats both of the above species is the Desert Nightsnake, Hypsiglena chlorophaea. One of 3 species of nightsnake found in Arizona, it kills them with a weak venom worked in by enlarged teeth in the rear of the mouth. It gets larger than the above, maxing out at about 2 feet long. Most I have seen, however, are in the neighborhood of 12″-14″. This one grew tired of me harrassing it while trying to take a photo and adopted a defensive head-at-the-bottom coiled position.