Cape Nightsnake

Cape Nightsnake, Hypsiglena ochrorhyncha ochrorohyncha

Cape Nightsnake, Hypsiglena ochrorhyncha ochrorohyncha. Snake collected from a garage in a residential area in the greater San José del Cabo area, Baja California Sur, March 2018. Length: 28 cm (11 inches). Identification courtesy of Gary Nafis, Californiaherps.com.

The Cape Nightsnake, Hypsiglena ochrorhyncha ochrorohyncha, is a member of the Columbridae family of North American Racers, Coachwhips and Whipsnakes. The Colubridae family comprises two-thirds of the world’s snake population with one thousand seven hundred sixty species placed in two hundred forty-nine genera. Many Colubrids are classified as venomous but very few are considered to be dangerous to humans. There are nine species in the Hypsiglena genus. The Cape Nightsnake is one of eight known subspecies of Cape Snakes within the Genus and Species Hypsiglena ochrorhyncha.  The Cape Nightsnake is known in Mexico as Serpiente De La Noche.

Cape Nightsnakes are small and slender in stature. They have a narrow flat head with nineteen rows of scales and eyes that have vertical pupils. Their body color matches their environment with various shades of gray, light brown, beige, tan or cream. Their back and sides are marked with dark brown or gray blotches and their underside is a uniform pale gray color. They are 18 cm (7.0 inches) in length upon hatching and reach a maximum length of 66 cm (2 feet 2 inches). They are nocturnal and consume a wide range of terrestrial vertebrates including frogs, lizards, lizard eggs, salamanders, and small snakes. The Cape Nightsnake is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Cape Nightsnake has a very limited range, being found from La Paz southward to the southern tip of the Baja California Sur. They are found in a variety of habitats including chaparral, deserts, grasslands, mountain meadows, sagebrush, suburban lots, and gardens. They require an abundance of surface cover for hiding and are commonly found around rocks and logs at elevations of up to 2,650 m (8,700 feet).


The Cape Nightsnake can be easily confused with two subspecies of Cape Nightsnakes, the California Nightsnake, Hypsiglena ochrorhyncha nuchalata (large blotches on the sides of their neck that often come together to form a collar and an eye stripe that comes to a point, just contacting the lateral blotches or collar) and the San Diego Nightsnake, Hypsiglena ochrorhyncha klauberi three-part nuchal collar formed by two lateral blotches that do not contact their eye stripe, and an irregular median nape spot). These two subspecies range from central California to southern Baja California and are very territorial. They differ  by their head markings and specific variations in the size and shape of their eye-stripes and dark blotches on their collar.

From a conservation perspective, the Cape Nightsnake has not been formally evaluated. Their populations are not well documented. They are not considered to be dangerous to humans as they possess only mild venom.