Captive breeding and new mutations have boosted the demand for western hog-nosed snakes.
Known by a variety of names, including the puff or spreading adder, the viper-headed hognose, and the Plains hognose, the western hog-nosed snake (Heterodon nasicus nasicus) was once treated as a marginal colubrid. It could usually be found on pre-Internet reptile price lists in the "Miscellaneous" section, with other snakes such as Thamnophis or Masticophis species. It was considered an "odds and ends" snake that, while it exhibited interesting behavior, garnered limited appeal due in part to its rather drab appearance.
Although it took time, in recent years the western hognose has emerged as a popular and varied snake that is increasingly sought after by pet reptile enthusiasts and breeders. This is due to a greater awareness of the snake's husbandry requirements, more widespread availability, and the ongoing introduction of a number of fascinating and distinctive color, pattern and genetic mutations (so many, in fact, that some western hognose enthusiasts think its popularity may eventually rival the corn snake or ball python).
Photo Credit: Jeff Clayton
Red tiger phase
Keeled Denizen of the Plains
First classified by French entomologist P. A. Latrielle in the early 19th century and later described by Baird and Girard of the Smithsonian Institute in 1852, the western hog-nosed snake was characterized as a non-venomous, small to medium-sized fossorial, diurnal (active during the day) colubrid of stout build with a sharply keeled and upturned rostral scale (resulting in the common name of "hognose"). An adult male typically ranges in size from 14 to 22 inches long with a weight of 60 to 120 grams. The appreciably larger female may reach 20 to 33 inches in length and 150 to more than 350 grams in weight (or even larger). The heavy, stout body is covered with keeled scales. Being a non-constricting colubrid, the western hognose uses its enlarged maxillary fangs to seize and restrain its prey, and also, in the case of toads, to deflate it.
The western hognose normally has a dorsal ground color of tan, brown, olive or gray with darker blotches or bars that are slightly irregular in shape. Both blotches and ground color may express a range of other hues, as well, including green, pink, red, orange and yellow. Sometimes, the blotches are separated into smaller, somewhat parallel rows of circular spots. Ventrally, the anterior scales are black with some irregularly dispersed white, yellow or orange coloration. Some specimens lack this coloration, and all ventral scales are entirely black.
The western hognose has the greatest range of the three subspecies that comprise H. nasiscus (the other two being the Mexican hognose, H. n. kennerlyi, and the dusky hognose, H. n. gloydi). The western occurs as far north as southern Saskatchewan and Alberta, Canada, southward to the western reaches of Kansas and Oklahoma, and further south through the Texas Panhandle. In this wide geographic area, the western hognose inhabits the grass plains and areas of loose aggregate, sandy soil, where it thrives on a varied diet of lizards, amphibians (including toads and salamanders), and small mammals such as mice, shrews and rats. On occasion, H. n. nasiscus also consumes the eggs of turtles and ground-dwelling birds. Interestingly, the species has been known to also consume road carrion.
A western hognose may employ any of several fascinating defensive ploys, or bluffs, to ward off danger when threatened. First, a burst of strong-smelling musk may be expelled from its anal glands to deter an attacker. If this does not do the trick, the snake will often tightly coil the lower part of its body, much like certain varieties of Crotalus, and emit an impressively loud hissing by forcing air through the unique bone structure of its skull and heavily upturned and keeled snout. While in this coiled position, it will also flatten its body, possibly to appear larger to an aggressor, and it will also flatten its neck or "hood" like a cobra. Finally, if all these ploys fail to ward off the danger, a western hognose will roll over onto its back, mouth agape, and feign death.
Enclosures for the Western Hog-Nosed Snake
A baby western hog-nosed snake may be kept in a relatively small enclosure, such as a small aquarium or a plastic shoebox with adequate ventilation. Aquariums of 20 gallons are ideal, as long as they provide a larger floor area. I house all my animals individually. For my adults, I use sweater boxes in a rack system. Each box measures 28 inches long, 16 inches wide and 6 tall. Babies are housed in plastic Rubbermaid or Sterilite shoeboxes, measuring about 14 inches long, 6 inches wide and 4 inches tall.
I prefer simple enclosures for both neonates and adults, with an easily accessible water dish that is not prone to tipping over, a few hides and adequate substrate. For the hides, I often recycle plastic food containers. Anything that makes the snake feel secure and does not have sharp edges can work. For younger hognoses, I recommend a plain newspaper substrate because it is economical, eliminates the potential of substrate ingestion and impaction, and it prohibits the growth of bacteria. For adults, aspen bedding or recycled newspaper products are good, and allow snakes the opportunity to burrow.
Heating and lighting are important. Full-spectrum lighting can be used and adjusted to follow seasonal changes. Its use is especially important if you are considering a breeding program. Place heating elements at one end of the enclosure, where a basking spot can be located. All of my heating elements are homemade, but you can purchase lighting from any reptile store or online. The other end of the enclosure should be cooler, allowing a temperature gradient. Air temperature at the warmer end of the enclosure should be around 90 degrees; the cooler end in the high 70s.
Western Hog-Nosed Snake Feeding Tips
Hatchling western hognoses will usually feed on small, frozen/thawed pinky mice. Moisten a pinky in tap water and, using small forceps, introduce it to a baby snake by nudging the head of the mouse under the snake's chin. You will find most hatchlings will be curious, and will drink the water off of the mouse. This is a good sign, and normally results in the snake taking the meal. It takes a little practice, so be patient. Some hatchlings, when confronted with food for the first time, will hiss and slither away. Others may roll over and feign death. These behaviors are normal. If they occur, attempt feeding later, after the snake has calmed down.
Some hatchlings may refuse the pinky even after repeated attempts. If this happens, try scenting the pinky with a 1:1 mixture of canned tuna or salmon juice and water. You can have the mixture prepared beforehand; it stores well frozen in a closed container. Some keepers will scent pinkies with toads or frogs, but I don't recommend this because it will be difficult to get young hognoses off toad-scented items and on to unscented meals, which should be your goal. Offer food weekly or every 10 days. Females that will be bred require food more often – every four to five days. Meal size depends on the size of the snake. Normally, a large female will readily eat a jumbo-sized mouse at each meal, sometimes two. If feeding more than one food item to a snake per meal, consider moving to a larger-sized food item. This also holds true for feeding pinkies to babies.
Breeding Western Hog-Nosed Snakes
The western hognose is easy to breed. The first thing to consider when undertaking a breeding project is to make sure you have a pair of properly sexed animals. Western hog-nosed snakes are generally easy to sex after their first shed, which occurs a day or so after hatching. The "popping' method is usually the most accurate method to determine their sex. This is done by gently applying pressure toward the posterior end of the snake's tail, and rolling the thumb forward toward the cloaca. The presence of hemipenes at either or both sides of the cloacal pouch will indicate a male; their absence indicates a female. Also examine the width and length of the tail; males have longer, more narrow tails, and females' are shorter and wider at the base. Some breeders probe their babies, but this is not recommended for the western hognose due to the small size of hatchlings. Neonates are normally between 5 to 7 inches long at birth.
After determining sex, also consider the age and size of the snakes. Male western hognoses are generally mature and ready to breed at 1 year of age, and should weigh around 70 grams or so (although smaller males have proven to be successful breeders). Females are typically considered mature at 2 years of age, and their weight should be at least 250 grams. Breeding occurs after a period of brumation for both sexes. Prior to brumation, cease feeding the snakes for two weeks to clear their digestive systems. After the two weeks, gradually drop their cage temperatures over the third week from the normal high to a low of 50 to 60 degrees Fahrenheit. A corresponding reduction in the daylight cycle, from the standard 14 to 16 hours per day down to eight hours, is another needed stimulus when considering breeding.
It is generally safe to brumate western hognoses for two to three months, sometimes even longer. Because wild specimens often brumate in burrows, their exposure to light during the cooling period should be minimal. Inspect the snakes and their cages weekly to ensure they have clean water and are not experiencing drastic weight loss or excessive lethargy. Do not feed them at all during the brumation period.
After brumation is complete (I usually time this to occur during the second week in February), over the course of one week, gradually increase the snakes' cage temperatures and increase the light cycles back to their normal levels. Once normal cage temperatures have been achieved, offer the male food every week, and the female food twice a week. A female western hognose will be receptive to breeding after going through an ovulatory shed cycle, which normally takes place within a month of being back to normal temperatures. When a pronounced swelling of her lower body occurs, it is time to introduce the male to her for a rotational period of two to three days, or until you have visually confirmed the snakes have bred at least twice.
Egg-Laying and Hatching
The gestation period for western hognoses is generally between 28 and 45 days, and it is important to offer the female a meal twice weekly during this time. Normally, she will refuse food two weeks prior to laying eggs; however, some females will continue to take small meals.
Egg-laying is preceded by a pre-egg-laying shed that occurs seven to 12 days before oviposition. Provide the female with a nesting box; this can be a plastic container partially filled with damp sphagnum moss, with a secure lid and a hole cut out of its top. Prior to egg-laying, the female will be restless, wandering around the cage looking for a place to lay her clutch. Eventually, she should lay them in the nesting box. There are many variables that play into clutch size, including the size of the female, her age and the size of the eggs. Clutches can be anywhere from eight to 25 or more eggs.
After the eggs are laid, remove them from the nesting box and place them in an incubation container with moistened vermiculite. Instead of punching holes in the lid, do so in the sides of the container. Place the container in an incubator, and incubate the eggs at 78 to 84 degrees. Inspect them periodically, but try not to disturb them. Hatching should occur after 48 to 60 days of incubation, depending on incubation temperatures. Hognose eggs do not adhere to each other like the eggs of many colubrids, so they are easy to position singularly in an incubation box. Bad eggs are easy to identify. They are mostly misshapen, small or yellow in color, with a waxy or wet appearance. Because the eggs can be laid in an incubation medium without coming into contact with neighboring eggs, there is no immediate need to remove eggs that might be considered bad. However, if some clutch eggs appear bad, they can easily be relocated to a separate container. It is important to remember to try not to turn the eggs after they have been placed into a container.
Once the neonates begin to emerge from their eggs, it is important not to bother them. They will fully leave their eggs once they have absorbed the yolk. At that time, place all the babies together in a plastic shoebox with adequate ventilation, damp paper towels and a small water dish. They will stay together until after their first shed, when they are ready to be fed and sex can be determined.
Western hog-nosed snakes live in areas of relatively low humidity, so it is a good idea to provide more ventilation in areas of higher relative humidity and somewhat less in areas where there is greater aridness. Proper ventilation is made by providing the enclosure with good air flow. Personally, I have found that hognoses do quite well in the southeast United States with high humidity. An indication of too much moisture is the presence of condensation on the walls or container lid. To remedy this, increase the ventilation to keep the enclosure dry. Providing the animal with a smaller, as opposed to larger, water bowl also helps to decrease the humidity. Temperatures and lighting should be at the standard levels, and the babies should shed within a day or so after emerging from the egg. Their first meal can be offered seven to 10 days after they hatch, using the techniques mentioned previously.
Exciting Western Hog-Nosed Snake Mutations
The increased availability of captive-bred western hognoses has lessened the need to collect wild specimens, although some are occasionally needed to diversify and strengthen existing captive bloodlines. The western hognose is not considered endangered throughout most of its range, but in a few states – such as Colorado, Iowa, Illinois and Missouri – it is protected. As with the collection or purchase of any native reptile, please check your state's current legislation regarding its status.
A steadily increasing number of color and pattern phases and genetic mutations have made the western hognose an exciting species to add to collections. The early 1990s saw the origination of at least three distinct forms of amelanism in the pink pastel albino, albino and T+ albino (then called a hypo). Later, the introduction of the anerythristic gene allowed for breeders to begin work on the double recessive snow, still quite rare in collections, to be followed shortly by a form of ghost combining T+ albino and anerythrism.
In the last few years a true form of hypomelanism has been identified, and these hognoses are marketed as a "smoke" morph. There's also a lavender gene, resulting in a new unrelated type of single recessive snow. Several pattern mutations have opened up a world of possibilities when combined with these genetic mutations. These include the very popular co-dominant anaconda phase, the jungle, spider and others. The next decade will be very exciting to see what new designer morphs are being marketed, as new morphs seem to occur almost every year.
Western hognose bites on humans are very rare, and they only occur as a feeding response, not as a sign of aggression on the part of the animal. Some western hognoses are aggressive feeders, so it is important to use hemostats when feeding or to leave food items in the cage with the animal, allowing them to eat when desired. Many western hognose bites result in little to no effects, but some bites, probably those of longer duration, do sometimes result in localized swelling that subsides in about a day or so. The saliva of the western hognose has been identified as a cocktail of protolipase enzymes. It should be noted that nearly all life forms on earth have these enzymes as well. While I do know people, including myself, who, after being bitten, do experience localized swelling, I do not know of anyone or research that suggests there are adverse allergic reactions related to a bite. Many, including herpetological experts and other breeders, believe that they are harmless.
The wide array of western hognose colors, patterns and genetic mutations now available, coupled with the ease in keeping and breeding this marvelous species, makes it very easy to see why the western hognose is rapidly becoming one of the most popular colubrids available today.
Jeff Clayton is a high school history teacher in Alabama. He has bred snakes for 25 years and has worked with western hog-nosed snakes for much of that time. He owns a diverse collection of high-quality animals at his private breeding facility. Visit his website at cahabariverreptiles.com, or email him at firstname.lastname@example.org.