The narrow-headed gartersnake (Thamnophis rufipunctatus) is a predominantly aquatic, non-venomous snake and is distinguished from other gartersnakes of its genus by the lack of stripes along its body and its elongated, triangular head. The narrow-headed gartersnake’s color ranges from olive to brown with dark spots along its body. They can reach a maximum size of four feet and females are larger than males. They have a long prehensile tail and their eyes are situated high up on the head, adaptations for their aquatic lifestyle.
Narrow-headed gartersnakes are found in central Arizona east into western New Mexico. There is a second population in Mexico that ranges from northern Chihuahua into Durango. Their preferred habitat is along rocky creeks and streams at elevations of 4, 000 – 7, 000 feet where there is abundant vegetation. Oak Creek Canyon in central Arizona is home to one of the largest populations.
For the majority of time, narrow-headed gartersnakes are in or around water and primarily eat fusiform (torpedo shaped) fish such as trout and dace, salamanders and tadpoles. Narrow-headed gartersnakes are excellent swimmers, but use their tail to anchor themselves underwater to wait and then ambush prey that comes near. They bask near the water using vegetation for cover and camouflage and flee into the water at any sign of danger. The home range of these snakes is relatively small, but they travel quite far in the fall to hibernation sites that are safely above the floodplain.
Narrow-headed Gartersnake Conservation
Recent surveys suggest that populations of narrow-headed gartersnakes have declined by at least 50 percent over the last 20 years. On July 7, 2014 the species was listed as “threatened” under the Endangered Species Act and is a species of special concern by Arizona, New Mexico and the U.S. Fish and Wildlife Service. One of the main reasons for this decline is the presence of invasive species. Bullfrogs and crayfish consume young snakes. Sport fish like sunfish and catfish have bony spines that can cause injury when narrow-headed gartersnakes try to swallow them. Habitat has also been lost due to the damming and diversion of waterways.
At the Phoenix Zoo
The Arthur L. and Elaine V. Johnson Foundation Conservation Center at the Phoenix Zoo currently has a breeding group of five narrow-headed gartersnakes. Zoo guests can see these snakes on most days either basking on their logs or hunting fish in their water bowls.
To stop the decline in numbers a Gartersnake Working Group was formed with members from Arizona and New Mexico Game and Fish Departments, U.S. Fish and Wildlife Service, Phoenix Zoo and several other institutions, including Arizona State University. This group focuses on preventing habitat loss and recovering the species. Three years ago, individual narrow-headed gartersnakes were brought into the managed setting in hopes of learning more about their care and management and with the hopes of producing offspring to augment populations in the wild
In 2009, we had the first breeding, but no pregnancy resulted. In 2010, we had a breeding that resulted in a pregnancy, but no birth. On the morning of July 2, 2014, a four-year-old gave birth to 18 neonates in the Zoo’s specially designed outdoor Suzan L. Biehler Herpetarium. This reproductive event is the culmination of years of husbandry work and scientific research by the Zoo’s conservation staff.
There is still a lot that we do not know about the breeding and behavior of this species; however, we have gathered a great deal of information that was not known previously. We have compiled this information into a Narrow-headed Gartersnake Husbandry Manual so that it can be shared with others who may want to help with the conservation of this species.