The Reptiles and Amphibians of Arizona

Online Field Guide to The Reptiles and Amphibians of Arizona

Chihuahuan Hook-nosed Snake (Gyalopion canum) Arizona
Santa Cruz County, Arizona

Cochise Co., AZ

CHIHUAHUAN HOOK-NOSED SNAKE
Gyalopion canum

Non-Venomous

DESCRIPTION: A small (up to 380 mm or 15″ in total length), relatively stout-bodied, gray, yellow-brown, or tan colored snake with more than 25 dark gray or brown, zigzag shaped bars across the back. A brown or gray-brown mask crosses the top of the head and covers the eyes on most specimens. The underside is pale or white, often with a pinkish or salmon tint. The pupils are round. The scales are smooth. The snout (rostral scale) is upturned on the leading edge and flat or concave on top.

DISTRIBUTION: This snake occurs in the foothills, bajadas, and valleys of southeastern Arizona at elevations below approximately 6,000′.

HABITAT: It is primarily associated with Chihuahuan Desertscrub and Semidesert Grassland communities but it is also encountered in Madrean Evergreen Woodland. In Arizona this snake is most frequently encountered on gentle sloping bajadas or in low foothills with rocky or gravelly soil grown with creosotebush or grasses. It is also occasionally encountered in the lower reaches of mountainous terrain along ridges and in canyons.

BEHAVIOR: This secretive ground-dweller spends most of its time below the surface of the soil in burrows. It is primarily nocturnal and evening crepuscular when surface active. It is also occasionally encountered during the day in cloudy or mild conditions. Encounters are often associated with recent rains. It hibernates during the cold months of late fall and winter. This snake is rarely seen in Arizona because of its fossorial nature but when conditions are favorable for surface activity it is not uncommon to encounter more than one on a single outing. When threatened it exhibits several defensive behaviors including jerking the body from side-to-side, striking with mouth closed, and making a popping noise by forcefully everting the lining of the cloaca. It presumably uses its “hooked” snout to root through surface debris and under rocks for prey.

DIET: The Chihuahuan Hook-nosed Snake feeds on small spiders, insects, centipedes, and scorpions. Captive specimens have also eaten snakes, lizards, and small mice.

REPRODUCTION: A clutch of up to 4 eggs is laid in late spring or early summer.

By Thomas C. Brennan

Bartlett. 2000. Snakes of North America: Western
Region. Gulf Publishing Co. Houston, TX

Brennan, T. C., and A. T. Holycross. 2006. A Field Guide to Amphibians and Reptiles in Arizona. Arizona Game and Fish Department. Phoenix, AZ

Degenhardt, W. G., Painter, C. W., and Price, A. H.. 1996. Amphibians and Reptiles of New Mexico. University of New Mexico Press. Albuquerque.

Fowlie. 1965. The Snakes of Arizona. Azul Quinta Press, Fallbrook, California

Stebbins. 1985. Western Reptiles and Amphibians. Houghton Mifflin. New York, NY

Chihuahuan Hook-nosed Snake (Gyalopion canum) Arizona Range Map

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