Image Credit : Brandon Ricks
Bitis rhinoceros is a large bodied venomous viper species. They have a distinctive set of enlarged nasal scales that look like a pair of horns on its nose, which distinguishes them from Bitis gabonica.
Also, in Bitis gabonica, the dark triangular marking leading back from the eye towards the angle of the mouth is divided while in Bitis rhinoceros it is not.
- Scientific name : Bitis rhinoceros
- Distribution : Guinea (Conakry), Guinea-Bissau, Liberia, Sierra Leone, Ivory Coast, Ghana, Togo
- Average Size : 1.5 m (5 ft)
- Life Span : 20 years or more
- Difficulty : Advanced
Housing Bitis rhinoceros can be as simple, or as eloquent, as the keeper desires. We will outline out preferences, based upon 30+ years of keeping/breeding with a lot of failure tossed in for good measure. It is our hope that our hard-won success with this species will negate much of the trial-and-error that was the norm in the 1970’s-1990’s, as we figured out the care of this magnificent species.
For newborns though 0.9 meters (3 feet), we routinely use standard rack systems, ranging from 0.3 x 0.6 x 0.15 meters (1 x 2 x 0.5 feet) through 0.45 x 1 x 0.2 meters (1.5 x 3.2 x 0.6 feet) accordingly. As soon as a Gaboon reaches 0.9 meters (3 feet) at our facility, it is being groomed for breeding purposes. At that point, they are transferred to breeding cages to be grown-up and acclimated to their surroundings well in advance – frequently 2 years, before breeding trials commence. While our setups may seem extravagant, especially to Americans, this is what works for us, year after year, with all three species of Bitis gabonica, Bitis rhinoceros and Bitis nasicornis. Breeder cages are set up in one of two ways, depending on space and numbers in a current population.
Set-up #1: Our preferred set-up is a 3 x 1.5 x 0.9 meters (10 x 5 x 3 feet) cage. It is constructed to be waterproof, with floor drains and a sloping floor to facilitate drainage. Substrate is addressed below. This cage has numerous logs and stumps set up to act as visual barriers, and is heavily planted with common Pothos vines as they grow quickly, are inexpensive, tolerate abuse by heavy-bodied snakes, and foster contact security for this rainforest-dwelling species that relies upon camouflage. We routinely house 2.3 adults, up to 1.7 meters (5.5 feet) + in length, year-round, in such an enclosure, with no hostility between males (except during non-injurious ritual combat in the breeding season) once the “feeling out” process is complete upon initial introduction. Visual barriers are the key.
Set-up #2: We are fortunate to be in possession of what we believe to be a group of hypo-melanistic or pastel morph Bitis rhinoceros (yet to be proven). For controlled, selective breeding, we have enclosures that measure 2.4 x 1.2 x 0.9 meters (8 x 4 x 3 feet). These are similarly waterproofed (concrete and stucco construction), have numerous logs and stumps, and heavy Pothos plantings. We house 1.1 in these enclosures, year-round. We feel that male-to-male combat is required for repeated, successful breeding, so we introduce smaller, subordinate males, throughout the breeding season, always personally monitored to avoid injuries, so the designated male we want to breed is guaranteed to “win” the challenge. As with many other species, we feel that females will not reliably ovulate unless exposed to such combat trials. For us, breeding season, in Central Florida, USA, is clustered between September/January, but we have also found that “seasons” can be manipulated to induce breeding at almost any time of year.
We have never had a Bitis rhinoceros use a hide box, and simply do not provide one. Young snakes will wiggle down into the substrate with only the spinal ridge and head protruding instead. Our adults are always provided with logs and plants to tuck into for contact security and a feeling of camouflage. These snakes appear to be acutely aware of their remarkable ability to camouflage, given the opportunity with a mixture of plants, logs, leaves, etc.
Substrate for Bitis rhinoceros can be forest-floor mixtures of peat, soil, coir, sand, leaves, etc. For young animals, we simply use shredded aspen, and have never had any issues with gut impactions, though we do monitor all feedings and go so far as to use forceps to gently remove any fiber of shavings that the snake, or moist rodent, may move toward the mouth before swallowing occurs. These snakes are remarkably tolerant of such procedures as long as one is careful, slow, and deliberate.
For larger breeding cages, our substrate is as follows, from base to surface: A base layer of chicken-egg sized rocks, pea-gravel, 0.02 meters (0.06 feet) of coarse sand, 0.1-0.15 meters (0.3-0.5 feet) of organic potting soil/sand at a 50/50 ratio, topped by a loose succulent plant-type mix of 50/50 soil/coarse Perlite and large-chunk hardwood mulch to allow the snake to experience high humidity, while remaining out of direct contact with a constantly moist substrate. Upon this the Pothos are free to root and expand. We are plant people as well, so this is a common mixture for us. The goal is a free-draining mixture, that also holds enough water to maintain a humidity level that parallels a rain-forest, while avoiding swampy surface conditions that may lead to respiratory issues. There is significant room to play with this mixture based upon your climate and local conditions. Bottom line: Humid, but not wet. Free-flowing fresh air without stagnation. Rainforests can be surprisingly cool with evaporation scenarios not immediately obvious to our climate-controlled minds.
Lighting – Heating
Young snakes in a rack system are exposed to our ambient room temperature of 25.5-28 °C (78-82 °F) daytime with a drop to 22-24 °C (72-75 °F) at night. Light conditions are low and fairly dark, as in the understory of a rainforest. Bitis rhinoceros are not tolerant of excessive heat, do not do well in constantly hot environments, and will not feed and/or will regurgitate at temperature extremes.
Breeding cages are maintained with a basking lamp at the far-end that maintains 27-32 °C (88-90 °F) during the day, with a timer-controlled, night-time red lamp that maintains a temperature of 29-31 °C (84-88 °F) from March through August for potentially gravid females to nocturnally bask if they choose. The cages are relatively dark, with no supplemental light provided. While we know of other successful breeders with different experiences, we never have any snake other than gravid females use a basking light and use this as a general indicator of successful breeding. We maintain 12/12 light/dark cycles year-round.
Water is where Bitis rhinoceros become problematic for many keepers, even for those with significant experience and success with other species. Have you noticed that many hundreds, if not thousands, of Gaboons are imported each year, yet very, very few are universally available as CBB outside of Africa? Where do they all go? The answer is not one we generally want to acknowledge. Renal failure deaths are frequently, and erroneously, attributed to fatal parasitic infections.
Imports come in seriously dehydrated, even if they look flawless. In nature, Bitis rhinoceros drink primarily off of their coils from the torrential rains they experience on a daily basis. These are not snakes accustomed to drinking from standing water, as it is simply not necessary in their home environments. These snakes all come in in some form of renal failure – every single one. Read that as many times as it takes to sink in. This is also the case with Rhinoceros Vipers, to an even greater extent.
With imported/newborn babies – soak, soak, soak daily in clean water. This cannot be emphasized enough. They can also be sprayed with commercial greenhouse sprayers to mimic rainfall, and will drink and drink for long periods. They can also be gently hooked over to a shallow water dish, the head then gently tipped into the water, where they will drink large amounts of water. After a series of exposures, they will eventually recognize standing water as such and seek it out. When in doubt, soak, spray, or tip into the water. Commonly cited literature suggests using an aquarium air-stone to roil the water surface of a water dish to attract the snake and atomize water particles as an alternative. While we don’t discount this as it works very well for many tree viper species, we have never had success with this approach with Gaboon Vipers.
All of this being said, all cages are maintained with large, shallow water dishes at all times. Large breeder cages contain a 24” x 36” x 8” concrete mixing tub with shallow sloping sides, full of fresh water at all times. Snakes will regularly soak in these tubs and defecate in them.
Here, large breeder cages are also outfitted with simple DIY automated rain systems. An inexpensive in-line timer, set to “rain” in the morning, mid-day, and afternoon comes on and fully rains on the enclosure for between 1 – 20 minutes per episode, depending upon the season we are attempting to replicate. The higher, more frequent rain periods correspond to the wet, breeding season, and are key to inducing successful breeding. For smaller set-ups, a simple greenhouse sprayer can easily be modified to rain upon the enclosure for an appropriate period of time. Hand spraying is not to be discounted, but takes more dedication and attention to daily routines to accomplish effectively. This also serves to stimulate gastric motility and defecation. Snakes come alive during rains and will actively crawl and explore the entire cage.
We house newborn through 0.6-0.9 meters (2-3 feet) snakes at a general humidity of 75-85%. Despite the seemingly logical extrapolation that rainforest snakes would need near 100% humidity, our years of experience and failures support a drier environment for young animals. Breeder animals are maintained with rain cycles as above. Breeder cages, whatever the dimensions, have a top that consists of ½” mesh over the full length/width of the cage to allow for full air flow. It should be mentioned that a main fan is employed in the snake room that extracts/exchanges the full volume of the room every 10 minutes with fresh air. While we realize this is not within the grasp of all keepers, we feel the need to mention all pertinent facts as we have experienced them.
Bitis rhinoceros are not generally difficult feeders. Over-feeding is usually more of an issue than under-feeding. It is a simple matter to push an 8” newborn to close to 0.9 meters (3 feet) within one year, but such a snake will typically suddenly die at year 3-5 just as an obese human has a shorter lifespan. After decades of trial and error, we feed a medium sized meal, and do not feed again until the previous meal is defecated. Our animals are lean, not fat, active, and healthy. Females are fed a bit more heavily prior to breeding, and in the first 2-4 months after successful breeding has taken place. Males should be kept lean. While seemingly skinny by current standards, males will not successfully breed and will frequently show no interest in breeding if they are too heavy. If you feel you are doing everything correctly, yet are still not seeing breeding activity, obesity is usually the issue. Fat does not equal happy in the case of Gaboons!
Small meals, especially with recent imports, are the best course of action. If regurgitation is a problem, first evaluate temperatures. If too cool or hot, adjust as necessary. If temperatures are correct, too large a prey item is usually the issue. Reduce prey size. Just because a Gaboon appears to be large enough to handle a large meal does not mean it should!
Bitis rhinoceros can appear to be placid, easy to handle/manipulate animals. This is certainly true 98% of the time – especially during the day vs at night. That great liberties can be taken with most animals is obvious by that lack of deaths, given the frequent Facebook postings of individuals doing stupid things with Gaboons. It’s the 2% of the time that proves catastrophic, if not fatal. These snakes are amazingly fast, agile, and can accurately strike in any direction, even from the rear. Their venom is a horrific combination of hemotoxins and cytotoxins that translate into a crippling, if not fatal bite, should one occur. The South African Polyvalent Antivenin is quite effective and at least 10-20 vials should be maintained by any responsible keeper outside of their normal range.
Young animals are easily handled by standard methods. Large, heavy-bodied adults are best handled with wide hooks that spread the weight and bulk of a heavy animal over the largest surface area possible.
As with all snake species, daily spot cleaning should be the norm, with full cage break down cleaning every couple of weeks/months, depending on set-up. We employ heavy plantings and micro-organisms such as springtails to establish a bioactive substrate that minimizes full cleanings. Anoles, skinks, etc., can be established for fly control in large rainforest enclosures with excellent success.
With adequate humidity, shedding is rarely an issue with Bitis rhinoceros. To be honest, we cannot remember a single episode of shedding difficulty, excepting very roughly handled snakes in the 1980’s – happily a thing of the past.
Potential Health Problems
Respiratory infections are occasionally an issue with high humidity and poor air circulation, though this is rare. More common are Protozoan infections/proliferations, as well as roundworm and lungworm infections/proliferations. While we will never advocate against routine fecal exams and wormings, we, for one, do not routinely worm imported Bitis rhinoceros unless symptoms or problems present. This is for a few reasons.
As mentioned previously, these snakes tend to come in dehydrated and many wormers heavily tax the kidneys and/or liver. If the animal is already at a metabolic disadvantage, the addition of wormers may tip the snake over the edge and kill it. We prefer to set the snakes up as outlined above and observe. After a period of establishment, proper temperatures, and solid feeding, with a 6-month quarantine period away from the main collection, we then evaluate the need for worming. While not a popular opinion, we find that prophylactic worming is only necessary in 25% of cases. If required, standard doses of Panacure and Flagyl are employed per standard doses and norms easily available in a Google search.
It’s highly recommended for every venomous species that you keep or interested to keep to have the bite protocol. Each species has a dedicated bite protocol that includes general information regarding the species, information about their venom and signs and symptoms of envenomation if bitten. It also includes a detailed information about first aid (what to do and what not to do), specific treatment recommendations for medical personnel to provide appropriate care including information about the antivenom or antivenoms required for treatment. Finally it includes a list of people who specialize in snakebites and their contact information so they can be consulted to assist with the care if needed and a list of all the references used for the create the protocol.
The information contained in this care sheet reflect the opinions and methods of the mentioned breeder, based on their expertise and long-established experience.