Trans-Pecos rat snake

  (Redirected from Bogertophis subocularis)

Bogertophis subocularis, commonly known as the Trans-Pecos rat snake[2][3] or the Davis Mountain rat snake,[4][5] is a species of medium to large, nonvenomous rat snake in the family Colubridae. Bogertophis subocularis is endemic to the Chihuahuan Desert.

Bogertophis subocularis
Bogertophis subocularis.jpg
Trans-Pecos Rat Snake.jpg
Trans-Pecos rat snakes
at the Houston Zoo
Scientific classification edit
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Colubridae
Genus: Bogertophis
B. subocularis
Binomial name
Bogertophis subocularis
(A. Brown, 1901)
Bogertophis subocularis distribution.png

Geographic rangeEdit

The Trans-Pecos rat snake is found in the Mexican states of Chihuahua, Coahuila, Durango, and Nuevo León, and its range extends northward into Texas and New Mexico in the United States.[1][4]


B. subocularis has a row of small scales (suboculars) between the lower border of the eye and the upper labials.[5] This beautiful snake is yellow to tan dorsally with a series of black, or dark brown, H-shaped markings.[2] The eye is large and prominent, light-colored with a contrasting round black pupil. The tongue is pink. The dorsal scales are in 31-35 rows at midbody. The ventrals number 260-277; the subcaudals number 69-79.[3]

Adults are usually 36-54 inches (90–137 cm) in total length (including tail). The record total length is 66 inches (168 cm).[6]


The Trans-Pecos rat snake's habitat consists of desert flats and brushy slopes, and rocky outcrops where it dens.


B. subocularis feeds on small vertebrates.


A nocturnal species, B. subocularis is uncommon and rarely seen in the wild, save on warm summer nights during the breeding season. Nicknamed "suboc" by enthusiasts, it is nonaggressive when approached, even passive, and is easily raised in captivity.

Sexual dimorphismEdit

B. subocularis exhibits sexual dimorphism. Females are larger than males as adults. Adult males reach between 3.5 and 4.5 feet (1.1-1.4 m) in total length (including tail); whereas females grow up to 5.5 feet (1.7 m).[2][3]


The breeding season for B. subocularis runs through May and June, while egg-laying begins in July and ends by September. At nearly three months, their incubation period is lengthy for a snake, at the end of which a clutch of anywhere from three to 11 snakes, each 28–33 cm (11–13 in) in total length, hatch. As they are hatched during winter, the hatchlings may remain hidden underground for several months before venturing outside.


  1. ^ a b "Bogertophis subocularis ". The Reptile Database.
  2. ^ a b c Conant R (1975). A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition. Boston: Houghton Mifflin. xviii + 429 pp. + Plates 1-48. ISBN 0-395-19979-4 (hardcover), ISBN 0-395-19977-8 (paperback). (Elaphe subocularis, p. 197 + Plate 32 + Map 151).
  3. ^ a b c Smith HM, Brodie ED Jr (1982). Reptiles of North America: A Guide to Field Identification. New York: Golden Press. 240 pp. ISBN 0-307-47009-1 (hardcover), ISBN 0-307-13666-3 (paperback). (Elaphe subocularis, pp. 184-185).
  4. ^ a b Wright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock. 1,105 pp. (in two volumes). (Elaphe subocularis, pp. 255-259, Figure 79 + Map 23 on p. 223).
  5. ^ a b Schmidt KP, Davis DD (1941). Field Book of Snakes of the United States and Canada. New York: G.P. Putnam's Sons. 365 pp. (Elaphe subocularis, pp. 152-153, Figure 41).
  6. ^ Powell, Robert; Conant, Roger; Collins, Joseph T. (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xsiv + 494 pp. ISBN 978-0-544-12997-9. (Bogertophis subocularis, p. 384 + Plate 35).

Further readingEdit

  • Brown AE (1901). "A New Species of Coluber from Western Texas". Proc. Acad. Nat. Sci. Philadelphia 53: 492-495 + Plate XXIX. (Coluber subocularis, new species).
  • Rhoads, Dusty (2008). The Complete Suboc - A Comprehensive Guide to the Natural History, Care, and Breeding of the Trans-Pecos Ratsnake. Lansing, Michigan: ECO Herpetological Publishing & Distribution. 291 pp. ISBN 978-0978897956.
  • Stebbins RC (2003). A Field Guide to Western Reptiles and Amphibians, Third Edition. The Peterson Field Guide Series ®. Boston and New York: Houghton Mifflin Company. xiii + 533 pp. ISBN 978-0-395-98272-3. (Bogertophis subocularis, p. 360 + Plate 45 + Map 150).
  • Stejneger L, Barbour T (1917). A Check List of North American Amphibians and Reptiles. Cambridge, Massachusetts: Harvard University Press. 125 pp. (Elaphe subocularis, new combination, p. 84).
  • Tennant, Alan (1998). A Field Guide to Texas Snakes, Second Edition. Houston, Texas: Gulf Publishing Company. pp. 200–201.

External linksEdit