The distribution of Hypsiglena jani (brown), which now includes the two former subspecies Hypsiglena torquata dunklei (orange), and Hypsiglena torquata texana (yellow).
Hypsiglena jani, commonly known as the Texas night snake or the Chihuahuan night snake, is a small
species of mildly
venomous snake in the
familyColubridae. The species is native to the southwestern
United States and adjacent northeastern
Mexico.
H. jani grows from 10 to 16 inches (25 to 41 centimetres) in total length (including tail), record 20 inches (51 cm).[9] It is typically a light
gray or
tan in color, with dark
brown or dark gray blotching down the back, and has an unmarked underside. It has smooth
dorsal scales. The eye has a vertically elliptical
pupil. H. jani is
rear-fanged, and is considered to be venomous, though it is not dangerous to humans.
Behavior
As the common names imply, H. jani is a primarily
nocturnal snake.
Diet
The
diet of H. jani consists of primarily
lizards, but it will also eat smaller
snakes and occasionally soft bodied
insects.
Habitat
H. jani prefers semi-arid
habitats with rocky soils.
Reproduction
H. jani is an
oviparous species that breeds in the spring rainy season, laying 4-6
eggs that take approximately 8 weeks to incubate before hatching. The eggs average 27 mm (1.1 in) long by 10 mm (3⁄8 in) wide. The hatchlings are about 15 cm (5.9 in) in total length.[6]
Geographic range
H. jani ranges from southern
Kansas to southern
Colorado, and south throughout
New Mexico, the western half of
Texas to central Mexico.
^
abc"Hypsiglena jani ". The Reptile Database. www.reptile-database.org.
^Stejneger L,
Barbour T (1917). A Check List of North American Amphibians and Reptiles. Cambridge, Massachusetts: Harvard University Press. 125 pp. (Hypsiglena ochrorhynchus texana, p. 93).
^Taylor EH (1938). "On Mexican Snakes of the Genera Trimorphodon and Hypsiglena ". Univ. Kansas Sci. Bull.25 (16): 357-383. (Hypsiglena torquata dunklei, new subspecies, pp. 374-375 + Plate XXXVII, figure 1).
^
abWright AH, Wright AA (1957). Handbook of Snakes of the United States and Canada. Ithaca and London: Comstock Publishing Associates, a division of Cornell University Press. 1,105 pp. (in 2 volumes) (Hypsiglena torquata texana, pp. 326-330, Figure 101 + Map 30 on p. 315).
^Mulcahy DG (2007). "Molecular systematics of neotropical cat-eyed snakes: a test of the monophyly of Leptodeirini (Colubridae: Dipsadinae) with implications for character evolution and biogeography". Biol. J. Linnaean Society92: 483-500. (Hypsiglena jani).
^Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore, Maryland: Johns Hopkins University Press. xiii + 296 pp.
ISBN978-1-4214-0135-5. (Hypsiglena jani, p. 133).
^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.
ISBN0-395-19979-4 (hardcover),
ISBN0-395-19977-8 (paperback). (Hypsiglena torquata texana, p. 217 + Plate 33 + Map 170).
Further reading
Dugès A (1865). "Du Liophis janii". Mém. Acad. Sci. Lett. Montpellier6: 32–33. (Liophis jani, new species). (in French).
Powell R,
Conant R,
Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 figures.
ISBN978-0-544-12997-9. (Hypsiglena jani, pp. 409–410 + Plate 39).
Stejneger L (1893). "Annotated List of the Reptiles and Batrachians Collected by the Death Valley Expedition in 1891, with Descriptions of New Species". North American Fauna7: 159–228. (Hypsiglena texana, new species, p. 205).
Tanner WW (1944). "A Taxonomic Study of the Genus Hypsiglena ". Great Basin Naturalist5 (3 & 4): 25–92. (Hypsiglena dunklei, p. 48; H. ochrorhynchus janii, pp. 48–51; and H. o. texana, pp. 51–54).