Note: These species pages are in various stages of completion. Some are basically finished; others are very much under construction. Please be patient while I work on this section.

This is a moderately large, long-nosed, brown spotted snake found in aquatic habitat. It feeds mainly on fish; it has also been known to take amphibian larvae and tadpoles.

If you were to conclude from this description that this is a water snake instead of a garter snake, you would not be alone. This species has occasionally been reclassified as a water snake by some herpetologists, due to its scale patterns, lack of stripes, and a divided anal scale on some specimens. But this is a garter snake, similar to other aquatic species like the Sierra and Mexican Black-bellied Garter Snake.

As of now, this species is only found in Arizona and New Mexico. Mexican populations that were previously assigned to this species have been split off into separate species: the Southern Durango Spotted Garter Snake, Thamnophis nigronuchalis, in southwestern Durango state; and, more recently, the Madrean Narrow-headed Garter Snake, Thamnophis unilabialis, for populations in Chihuahua, Coahuila, northern Durango and Sonora. All three species are closely related and similar in appearance and habitat use. All are aquatic fish-eaters found at high elevations.

Though better known than its close relatives, this is still a poorly understood species compared to other garter snakes.

Conservation

The Narrow-headed Garter Snake is endangered in New Mexico and threatened in Arizona (note: this information may be out of date). The recent splitting off of Mexican populations into separate species means that Thamnophis rufipunctatus is now at risk throughout its range. New Mexico has a recovery plan for this species.

Captive Care

This is one of the long-nosed fish- and amphibian-eating species described by Rossi and Rossi (2003). Because of their diet, parasites will likely be a problem. They report that this species may accept scented mice, especially if they’re tease-fed. Ernst and Ernst (2003) call it a picky eater in captivity; Rossman et al. (1996) consider this a difficult species to maintain in captivity because of the diet and parasite issues. But in theory these snakes do not sound more difficult than, say, more stubborn water snakes. I’d be interested in hearing from people who have worked with this species.

If you have experience with this species and would like to share, please contact me.

For general information on keeping garter snakes in captivity, please see the Care Guide.

Articles and News

• 10 Nov 2014 Garter Snakes Threatened by Fire, Grazing in U.S. Southwest
• 8 Jul 2014 USFWS Lists Two Garter Snakes as Threatened
• 17 Jul 2013 Background on Two Threatened Snakes
• 10 Jul 2013 USFWS Proposes Adding Two Garter Snakes to Endangered Species List
• 18 Jan 2013 New Study Splits Off Mexican Narrow-headed Garters into New Species
• 18 Jan 2013 Updates to Species and State Pages
• 25 Jun 2012 Wildfire Threatens Endangered Garter Snakes

Sources