Reptiles of Arizona - Mexican Hog-nosed Snake (Heterodon kennerlyi)

Heterodon kennerlyi - Mexican Hog-nosed Snake
Cochise County, AZ

Cochise Co., AZ

Death-feigning. Cochise Co., AZ

MEXICAN HOG-NOSED SNAKE Heterodon kennerlyi	Mildly Venomous

DESCRIPTION: A medium (up to 760 mm or 30" in total length), stocky, yellowish-tan snake with brown to orange-brown blotches. The large mid-dorsal blotches are often somewhat muted. A row of small, dark brown, crisp-edged blotches runs along each upper side. Below this row, an additional row of large, muted, blotches runs along each side, followed below by one or two more rows of small muted blotches or spots. Two dark brown bars cross the top of the head between the eyes, the posterior-most of which runs past the back of the eye and down to the corner of the mouth. The pupils are round. Two large, crisp-edged, dark brown blotches mark the neck and are separated at the mid-dorsum by a third, smaller nuchal blotch. The head is large but is barely distinct from the thick neck. The scale on the snout (rostral) is enlarged, flat on bottom, upturned, keeled on top, and shovel-like. The underside of the body is checkered with large, rectangular, yellow-orange and black blotches. Some specimens have a nearly solid black belly. The underside of the tail is usually solid black. Adult females attain larger sizes than males. The dorsal scales are keeled distinguishing this snake from the Chihuahuan Hook-nosed Snake. DISTRIBUTION: This snake is found in the valleys of southeastern Arizona at elevations ranging from ca. 3,600' to ca. 5,100'. HABITAT: Heterodon kennerlyi is usually found in open areas with loose or sandy soil within Semidesert Grassland, Chihuahuan Desertscrub, and grassland communities. It seems to prefer relatively flat terrain including low valleys and gently sloping bajadas. BEHAVIOR: The Mexican Hog-nosed Snake is a primarily diurnal and crepuscular ground-dweller. It is occasionally active into the night during particularly warm periods. It hibernates during the cold months of late fall and winter. When threatened this snake will usually flatten the neck and posterior head and make repeated bluff strikes, each accompanied by a sharp hiss. If this fails to alleviate the threat the snake might perform an elaborate death-feigning display by flipping over onto its back, evacuating the cloaca, and opening the mouth widely. DIET: The shovel-like snout is used to root around in the soil for prey which includes toads, mice, eggs, lizards, snakes, and birds. There are two enlarged teeth on the posterior of each upper jaw bone (maxilla) which are used to inject a mild venom into prey. REPRODUCTION: Mating takes place in the spring and a clutch of up to 23 eggs is laid in late spring or early summer. Hatchlings appear during the late summer rainy season. 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 Lowe, Schwalbe, Johnson. 1986. The Venomous Reptiles of Arizona. Nongame Branch Arizona Game and Fish Department. Phoenix, AZ Stebbins. 1985. Western Reptiles and Amphibians. Houghton Mifflin. New York, NY

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