One of the most commonly-seen snakes in semi-urban areas in Arizona is also one of the most confusing. It’s brown, it’s big, it’s bad (if you ask its opinion, that is) and it’s … a Bullsnake? Gophersnake? Are those the same thing? Not really. If you live in Arizona telling the difference between a Gophersnake and a Bullsnake is easy:
Bullsnakes do not live in Arizona. All of the snakes that seem to be interchangeably called either Gophersnake or Bullsnake are all Gophersnakes. In Maricopa, Pinal, and Pima counties (where most of us live), they are all Sonoran Gophersnakes.
Bullsnakes and Gophersnakes are both real snakes, subspecies of the Gophersnake species Pituophis catenifer. In Arizona, we have two subspecies of Pituophis catenifer: the Sonoran Gophersnake, Pituophis catenifer affinis, and the Great Basin Gophersnake, Pituophis catenifer deserticola. What you do not see in this list of Arizona subspecies, however, is Pituophis catenifer sayi … the Bullsnake. And even more confusing, since sayi is a subspecies of the larger Gophersnake species, that means that while some Gophersnakes are also Bullsnakes, all Bullsnakes are also Gophersnakes. Whew.
The real Bullsnakes live throughout the central U.S., up into Canada, and down into Mexico. In the Southwest, their range ends to the West as it intergrades with Sonoran Gophersnakes in West Texas and eastern New Mexico. A great map of this distribution can be found here.
Is this that important? For most people, not really. While calling a Sonoran Gophersnake a Bullsnake is incorrect, the intent and general description of the snake and what it does are the same. If someone says they see a Bullsnake on their patio, it’s definitely not a Bullsnake, but I do know exactly what they are talking about. In this way the common name still does its job in providing a general description of what it is, and also highlights the difference in utility between use of common names and the more precise latin nomenclature.
Either way, Gophersnakes are harmless animals that are absolutely wonderful to have around the house and the best free rodent control you can get.
Photos of each below:
Sonoran Gophersnakes (the kind we have here in central and southern Arizona)
Bullsnakes (photos by Chad Whitney)