Small Snakes Of The American West
The great American West has long been a lure to reptile hobbyists. In southern Texas, for instance, it is always a thrill to come across a Mexican milk snake (Lampropeltis triangulum annulata) or a Texas indigo (Drymarchon melanurus erebennus). A little further west, gray-banded kingsnakes (L. alterna) or Trans Pecos rat snakes (Bogertophis subocularus) top the list. Arizona has a fantastic variety of desert rattlesnakes (Crotalus spp.), Gila monsters (Heloderma suspectum) and rosy boas (Lichanura trivirgata), and on the west coast, a number of kingsnakes and milk snakes (Lampropeltis spp.), rattlesnakes and rubber boas (Charina bottae) are often sought after.
Whether in California, Arizona or Texas, however, there are also a variety of often-overlooked, overtly small snakes that are fascinating in their own right. In this article, we’ll take a look at these “western miniatures.”
The Blind Snakes
Slender, wormlike, and extremely secretive, the blind snakes (Rena spp.) are evolutionarily distinct among snakes. First, as their common name suggests, they are, in fact, blind. They do have rudimentary eyes, each covered with a scale; however, blind snakes are burrowers by nature and spend most of their lives underground where having eyes probably is not so important. Second, blind snakes possess a well-developed pelvic girdle, a skeletal feature that indicates they had legs in the distant past. Even more than that, they have a well-developed vestigial femur or thigh bone attached to a tiny spur. Lastly, the blind snakes of the American west only have teeth on the lower jaw!
Gregarious in habit, sharp-tailed snakes (Contia tenuis) often congregate in large numbers.
Highly specialized in their feeding habits, the 6 to 16-inch-long snakes prey only upon certain ants and termites. Highly adept at following the pheromone trails of ants, they seem to prefer the eggs, larvae and worker ants, and avoid the soldiers. If a blind snake is attacked by its prey, it writhes on the ground and coats itself in a foul, cloacal discharge that serves to repel the ants.
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Ranging throughout the southwestern United States, blind snakes are generally found under rocks but are also encountered fairly frequently on roads at night. Like scorpions, they tend to fluoresce under an ultraviolet black light and can be detected from distances of 10 feet or more.
The Sand Swimmers
Nicknamed the “sand swimmers” by Charles Shaw, the late San Diego Zoo curator, and fellow author and friend Sheldon Campbell in their book, Snakes of the American West, this group of snakes is categorically small and extremely adept at moving through loose sand environments.
The banded sand snake (Chilomeniscus stramineus) is a highly specialized sand-dwelling species.
The banded sand snake (Chilomeniscus stramineus) has a whitish ground color and a series of brown-to-black bands usually interspersed with orange on its dorsal surface. Extremely small in size (6 to 10 inches), it is a highly specialized sand dweller that is found from southern Arizona into Mexico. Primarily an insectivore, the banded sand snake will eat crickets in captivity, though may sometimes also consume spiders, centipedes, scorpions and lizards. An occasional individual has been known to tie itself in a knot during the shedding process, a behavior that has also, interestingly, been noted in the yellow-bellied sea snake (Pelamis platurus). It has been theorized that this knotting behavior occurs in snakes that have fewer hard surfaces to push against in their environments, whether it be water or loose sand, while shedding.
Other denizens of sand-swept habitat are the shovel-nosed snakes (Chionactis spp.). The western shovel-nose (C. occipitalus ssp.) is found from southern Nevada into the deserts of southern California and western Arizona. Extremely limited in range in the U.S., the Sonoran shovel-nosed snake (C. palarostris organica) only occurs within the confines of Organ Pipe National Monument in southern Arizona. Both snakes are very attractive, rivaling tricolored kingsnakes in intensity of their orange and black bands. They measure 10 to 17 inches in length and are largely insectivorous, but also consume small lizards.
Searching for shovel-nosed snakes and not finding any under what would seem to be ideal conditions has puzzled biologists. A study found that activity in these snakes is influenced by air temperature and related subsurface sand pressure. However, their brief four to five-hour surface activity period is apparently also related to their most recent previous period of activity. A biological process known as circadian rhythm means the shovel-nosed snakes respond not only to favorable sand pressure and temperatures, but also to an internal 24-hour clock that signals them to move closer to the surface of the sand.
Another cool little (12 to 20 inches) snake of the western deserts, and one that is occasionally encountered on roads at night, is the spotted leaf-nosed snake (Phyllorynchus spp.). It is easily distinguished by its enlarged rostral shield that curves back over the nose like a folded leaf. One of the few North American colubrid snakes with elliptical pupils, this species is considered a burrower and is often found in close association with areas containing creosote bushes. There are two species that occur in the western United States, and both are notoriously difficult to maintain for any length of time in captivity. They will occasionally consume lizards such as banded geckos (Coleonyx variegatus) and their eggs, as well as crickets, but other than taking a photograph of one that is encountered, leaf-nosed snakes are best left alone.
The western hook-nosed snake (Gyalopion canum), like other Gyalopion species, is a stout snake with an upturned snout.
Two species of 6 to 19-inch long snakes with upturned snouts are known as the hook-nosed snakes (genus Gyalopion). Not exactly sand swimmers, they are confirmed burrowers, spending the day in gravelly soils and alluvial deposits. Hook-nosed snakes have rather stout, cylindrical bodies and a flat to upturned snout, thus giving them their common name. Chiefly nocturnal in habits, hook-nosed snakes are occasionally encountered on roads at night, especially after heavy rains. They exhibit a unique behavior that may serve as a defense mechanism: Upon being disturbed, they will writhe and contort their bodies as if in agony, before they extrude and retract their cloaca rather rapidly, resulting in a popping sound. This bizarre behavior also occurs in the Arizona coral snake, a venomous species that is sympatric with hook-nosed snakes.
Hook-nosed snakes are difficult to maintain in captivity, with the western hook-nosed snake (G. canum) possibly being the easiest. They feed predominately on spiders, scorpions and centipedes, but an occasional individual can be tricked into accepting dead pinkies if the scent of an acceptable prey item (such as a spider) is rubbed onto the pink.
Ground snakes (this is a western ground snake, Sonora semiannualata) vary in markings and coloration.
The 8 to 19-inch-long western ground snake (Sonora semiannulata) is a nocturnal species found in the western United States. Extremely variable in coloration and markings, specimens may be plain, barred or striped with a ground color of brown, gray, black or red. Inhabiting dry, sandy or rocky areas, the ground snake burrows in sand and also conceals itself in rocky crevices. It is completely nonaggressive and adapts quite readily to captivity, feeding predominantly upon invertebrates, including insects, spiders and centipedes. Kept in a relatively dry enclosure (of course, with a water bowl), western ground snakes will generally accept crickets, though a varied diet is recommended.
Woodland Miniatures, The Ring-necked Snakes and the Sharp-tail Snakes
Known for their conspicuous orange-to-yellow neck ring, the ring-necked snakes (Diadophis punctatus ssp.) are typically found in moist habitat near streams, ponds and lakes. Rarely encountered in the open, this earthworm and salamander-eating species is usually found under ground cover such as logs, rocks and boards. A number of subspecies occur in the west, the largest being the regal ring-necked snake (D. p. regalis), which can reach 2½ feet in length.
Ring-necked snakes (Diadophis punctatus) have a wide distribution throughout the United States.
Ring-necked snakes do well in captivity provided they are kept in a fairly moist environment with good ventilation. An occasional individual can be “tricked” into accepting pinkies using the scent-transfer technique mentioned earlier—by rubbing a preferred food item, such as a worm or a small snake, onto a dead pink, thus transferring the scent and making the pink mouse more acceptable to the ring-necked snake.
Another small snake is represented by two species found in moist upland habitat from California to British Columbia and is known collectively as the sharp-tailed snake (Contia spp.). Brown to gray in color, these foot-long, slug-eating species are known to be gregarious in nature; a group will often be found underneath the same log or in a relatively small area. There’s a report of one group in Alameda County, California, for instance, of 40 sharp-tailed snakes that was found in a small area, and another of 23 found in Linn County, Oregon. Two to nine eggs are laid in the summer, sometimes in a communal nest. One interesting aggregation found on a talus slope in Oregon included 51 lizard eggs, 292 snake eggs and 76 snakes, of which 43 of the eggs were identified as sharp-tailed snake eggs!
Named for the enlarged rostral scale or nose shield that looks like a folded leaf, the leaf-nosed snakes are some of the few non-venomous North American snake species that have elliptical pupils. This is a spotted leaf-nosed snake (Phyllorhynchus decurtatus decurtatus).
A miniature that barely meets the geographic requirement to be considered “western” is the lined snake (Tropidoclonion lineatum). Found from the Midwest into New Mexico and Colorado, this 9 to 21-inch-long species is similar in appearance to the striped garter snakes (Thamnophis spp.). Found in woodlands, prairies and even backyards, the lined snake is nocturnally active and feeds upon earthworms. Unlike most non-venomous snakes, the lined snake mates in late summer, immediately after giving birth to the previous year’s litter.
Rear-Fanged Miniature Snakes
Calling a colubrid snake “rear-fanged” is almost a misnomer. Many snakes that are considered harmless actually produce relatively mild toxins or venoms and have enlarged dentition in the rear of their mouths; however, only certain ones tend to get tagged as “rear-fanged.” Common North American species such as garter and ribbon snakes (Thamnophis spp.) and hognosed snakes (Heterodon) are two examples of species that are sometimes overlooked when it comes to mild envenomation in humans, but even species such as ring-necked snakes (Diadophis punctatus) secrete mild toxins.
Night snakes (Hypsiglena torquata) adapt fairly well to captivity and will eat lizards.
One genus that fits the category of being both a western miniature and rear-fanged is Tantilla, or the black-headed snakes. Averaging 8 to 18 inches in length, black-headed snakes are very widespread in the west yet are seldom seen. Sometimes referred to as “tantillas,” these snakes are generally nondescript in appearance, usually being tan to gray in body color with some sort of black coloration on the head, hence the common name.
Seven species and subspecies of black-headed snake occur in the western part of the United States; all are secretive, spending much time under stones and crevices, or in the burrows of small mammals. One species, the Plains black-headed snake (T. nigriceps), even has the undignified honor of having been found under dried cattle manure! Extremely non-offensive when handled, black-headed snakes feed upon centipedes, millipedes, spiders and earthworms. Some captive specimens have accepted waxworms and mealworms.
The night snakes (Hypsiglena ssp.) are other rear-fanged miniatures found throughout much of the west. Adults measure 12 to 26 inches in length, and as their common name suggests, are encountered predominately at night. One type of the few harmless American snakes that have elliptical pupils, night snakes are generally gray to beige in coloration with a series of darker brown blotches on the body.
Night snakes feed largely upon frogs and lizards, but have also been known to consume small snakes, salamanders, spiders, centipedes and insects. Live prey succumbs fairly quickly to their mild venom.
They are non-aggressive, relatively slow-moving, easy to handle and adapt readily to captivity. Night snakes will even feed upon the Mediterranean gecko (Hemidactylus turcicus), an introduced species that now has widespread distribution in the more southern parts of the U.S.
Unsung, unheralded, and generally underappreciated by many hobbyists, these smaller snakes (and limbless lizards) have unique characteristics and adaptations allowing them to survive in environments that can be very inhospitable. The next time you’re out herping within their range, be on the lookout for these smaller reptiles—there’s more to them than meets the eye.
R. Michael BURGER is a writer, artist, photographer and life-long reptile hobbyist with more than 50 herp-related articles in U.S. and European publications. He resides in Texas with his wife Veronica, where they maintain a variety of amphibians and reptiles.