The Reptiles and Amphibians of Arizona

Online Field Guide to The Reptiles and Amphibians of Arizona

Lichanura trivirgata trivirgata. Maricopa County, AZ

L. t. gracia La Paz Co., AZ	L. t. gracia Mohave Co., AZ	L. t. trivirgata Maricopa Co., AZ

L. t. gracia Maricopa Co., AZ	L. t. gracia Maricopa Co., AZ

ROSY BOA Lichanura trivirgata

Non-Venomous

DESCRIPTION: A medium-sized (up to 950 mm or 37″ in total length), heavy bodied snake with three wide, dark brown, black, orange, or reddish-brown stripes on a light cream, tan, or gray background. The head is only slightly larger than the neck and the tail is relatively blunt. The eyes are small and the pupils are vertically elliptical. The scales are smooth. The scales on the top of the head are small and rounded, unlike the large, flat head plates of most non-venomous snakes in Arizona. On males vestigial hind limbs are present in the form of two small spurs, one protruding from each side of the vent.

DISTRIBUTION: This snake is found in western, southwestern, and south central Arizona at elevations ranging from near sea level to just over 5,600′. It has not yet been documented from the many mountain ranges, with seemingly suitable habitat, between the known ranges of Arizona’s two subspecies.

HABITAT: In Arizona the Rosy Boa inhabits Sonoran Desertscrub, Mohave Desertscrub, and Interior Chaparral communities. In some areas it enters the lower reaches of Great Basin Conifer Woodland. It is usually associated with rocky or boulder-strewn habitat on mountains, bajadas or hillsides. This amazing snake inhabits some of southwestern Arizona’s hottest, driest, and most inhospitable mountain ranges.

BEHAVIOR: Although it is primarily nocturnal and crepuscular in Arizona it is also active on spring mornings and on mild or overcast days. The Rosy Boa is a slow moving ground-dweller that spends the majority of its life sheltered in burrows or deep within rock piles and crevices. It hibernates during the cold months of late fall and winter.

DIET: This powerful constrictor feeds on a variety of small mammals and birds.

REPRODUCTION: Mating takes place in spring. Three to 14 young are born in late summer or early fall.

REMARKS: The Rosy Boa is a member of Boidae, a family that includes the giant anacondas and large boa constrictors of South America.

SUBSPECIES FOUND INAZ:
DESERT ROSY BOA Lichanura trivirgata gracia. This subspecies is usually larger than L. t. trivirgata in AZ. The stripes are usually brown to reddish-brown or orange. There are usually two parallel rows of brown to reddish-brown spots running the length of the ventral surface.
MEXICAN ROSY BOA Lichanura trivirgata trivirgata. This subspecies is usually smaller than L. t. gracia in AZ. The stripes are
usually very dark brown or black. The underside has sporadic dark brown or black spots or blotches. There are usually dark markings around the vent on specimens from Arizona.

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

Brennan, T. C., and A. T. Holycross. 2005. A Field Guide to Amphibians and Reptiles of Maricopa County. Arizona Game and Fish Department. Phoenix, AZ

Brennan, Thomas C. and M. J. Feldner. 2001 Lichanura trivirgata trivirgata. Geographic Distribution. Herpetological Review 32(3).

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

Rosy Boa (Lichanura trivirgata) Arizona Range Map

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