Brazilian rainbow boas, or rainbows, make very docile-tempered pets that tolerate being handled, thrive in captivity, and don’t grow to a monstrous size like some other constrictors. Their beautiful colors range from a deep red to a bright orange, and they have contrasting-colored crescent shapes along their sides, which usually are outlined in black.
The gorgeous iridescence that shimmers across their body comes to you courtesy of microscopic ridges on the transparent top layer of skin, also known as structural coloration, that glow like a rainbow when they reflect light. This effect is very similar to how a glass prism works when daylight passes through it.
Rainbow boas live in the forests of South America, all the way up to lower Central America, and along the Amazon River Basin in Brazil, of course, as well as in coastal Guyana, Suriname, Peru, and parts of Columbia. Their prehensile tail helps them navigate the trees of that area while searching for food or maybe even trying to elude a predator.
Brazilian rainbow boas love warm temperatures and high humidity, which can present a challenge for novice snake keepers. Don’t let that discourage you, though. Challenges like maintaining warm temperatures and high humidity levels are easily overcome with knowledge, proper husbandry, and patience.
Always purchase any reptile from a reputable breeder that has captive-bred animals. Breeders are far more knowledgeable than a big box-style pet store, and they will have healthy, parasite-free animals that are eating. Breeders are ready to answer questions for people who are looking for answers about the animal/animals they specialize in breeding and caring for. There are some breeders that offer an “arrive alive” guarantee, so you know when your snake arrives, it should be alive and ready to rest in its new home.
You can find breeders online, on forums and breed-specific websites, and at reptile shows/expos. There is another benefit to buying from a breeder as well. You get to make a new friend in the reptile hobby. That’s always a good idea because there is so much to know about reptiles.
Hatchling rainbow boas are between 8 and 11 inches in length. When fully grown, females tend to be slightly longer and heavier than males. Female rainbows grow to be 6 to 7 feet long, and males reach between 5 and 6 feet long, on average.
Rainbow boas are most likely the only species of snake whose length is directly tied to its sexual maturity. Males are ready to breed when they are about 4 feet long, and females are ready to breed when they reach 4½ feet long.
Brazilian rainbow boas are a long-lived snake for sure. They usually reach 20 years old on average. There are reports of females reproducing at the age of 24.
Snakes are prone to some health issues, and the rainbow is no different. Some of the issues a snake could experience include constipation, respiratory infections, and parasites. For a more complete list, click here.
Young snakes up to about 2 feet long can easily be kept in a 20-gallon terrarium. After that, rainbows need to be moved into their adult enclosure. This enclosure must have a locking or securely fastening device on it. Rainbows are escape artists, and popping open a screen top that’s not locked tight is not a problem for this snake.
The enclosure for rainbows of any age or size must have enough room for them to move around and climb. They are not only terrestrial snakes, they are considered generalists, which means that in the wild, while they do spend a lot of their time on the ground, they are also excellent swimmers and climbers. Rainbows like to hunt for amphibians at the water’s edge, but not in the water, and climb up into the trees, with the help of their prehensile tail, and hunt for birds or bats.
With all that said, make sure your snake has an adult enclosure at least 4 feet wide and 2 feet deep and 4 feet tall. This is the minimum; the bigger the better. Make sure all the decorations in the enclosure are reptile-safe and are securely fastened so they can’t fall onto the snake and hurt it.
Also include a couple of hides. You can use cork bark, half logs, or an overturned container or old plastic container that’s been cleaned and sanitized, with a large hole carved out to make an entrance. Place one hide on the cooler side of the enclosure and the other about halfway between the coolest side and the warmest side. If the snake wants to cool off or warm up, it will have a place to “hide”.
If there is a branch in the basking area, make sure the branch is far enough away from the light, so the snake can’t reach up too close to the light and burn itself. This could be a challenge with a snake this long and is another reason some people say this is not a snake for beginners.
Place some live plants in the enclosure with young rainbows. Watering the live plants will help with the humidity levels, and the plants themselves will provide cover to help young snakes feel safe. Place fake plants in with adult rainbows because adults will crush and kill live plants as they move through and over them.
Lighting and Temperature
Rainbows are nocturnal. Therefore, you do not need UV lights like you do for other reptiles. If you want to see a rainbow boa glow, and who doesn’t, place a full-spectrum florescent bulb above the enclosure. This will work well for display lighting because the balance of the full-spectrum florescent lighting will show the rainbow in shimmering colors.
The snake will also benefit from having a regular day/night cycle, or photoperiod, to help keep its circadian rhythm going properly. Make sure the lights are on for no more than 12 hours per day. A good digital timer is fairly inexpensive. I have several I use routinely, and they are pretty much worry-free devices.
Because rainbow boas inhabit the tropical and sub-tropical forests of South America, the daytime temperature should be kept between 85 and 90 degrees Fahrenheit, and the overnight lows should be between 70 and 80 degrees Fahrenheit. If you live in an area that gets very cold in the winter, you’ll need to provide your snake with a source of heat. You can use red glass light bulbs; the red light doesn’t bother their vision and does provide heat.
Also, there are ceramic heat emitters that provide only heat and no light at all. Please do not use under-the-tank heating pads. They are known to be dangerous, and they go against nature. In the wild, heat comes from the sun, which is above the reptile, so quite a few reptiles dig into the ground to find a cool moist place to rest, away from the sun and its heat.
Here’s another reason why a lot of people say rainbow boas are not for beginners. While these people think beginner snake handlers are capable of getting the light and temperature requirements correct, they think beginners will have problems maintaining proper humidity levels. With that said, the correct humidity levels range between 70 and 90 percent. This species does very poorly in prolonged periods of low humidity levels, which is anything below 50 percent, which absolutely can cause health issues and even death.
Maintaining this level of humidity does require you to check the humidity levels throughout the day by looking at the hygrometer inside the snake’s enclosure. If the level is too low, simply take a squirt bottle with the same clean filtered water you provide in the snake’s water dish and mist the insides of the enclosure and the decorations, along with any sphagnum moss.
The humidity level will rise shortly thereafter and maintain for a few hours. If your schedule does not allow you to do frequent checks, there are some very nice automated misting systems on the market. Another way to maintain humidity levels is to use a fogger built for reptile enclosures (not Halloween parties).
They keep the humidity levels correct while also providing an amazing visual effect. Because foggers have smaller water droplets than misting systems, the entire enclosure will be moistened, not just what’s in the path of the misting nozzles. Both are easy to set up and will help a busy person or newer keeper maintain their snake’s humidity level and health.
So for all you novice keepers out there, the above-mentioned ideas are some of the easiest ways to help you maintain proper humidity levels for your reptile’s health. I see advanced keepers using these same methods and recommending them for use to other keepers. You got this!
There are some substrates that are great to use in your snake’s enclosure. Use one that can hold onto moisture because it’s what feels natural to the snake and it will help with the humidity level. Cypress mulch, orchid bark, and coconut husks/fiber are all great choices for substrate. Use them by themselves, or mix any or all of them together. Use sphagnum moss as well in different areas to help with maintaining the humidity level and as an added bit of functional decoration.
Do not use pine, cedar, or any other aromatic woods. Their oils are irritants to the snake and can cause serious health problems.
As far as this snake is concerned, if it’s a warm-blooded mammal that will fit into its mouth, it’s food. While these are mainly terrestrial snakes, in the wild, rainbow boas are known climbers, and their prehensile tail is a huge asset to them. Because these snakes are nocturnal, they can slowly climb up a tree at night while birds are sleeping and have one of them for a meal. Climbing also gives rainbows the opportunity to get into a tree and get positioned to grab a bat when it flies past. They have to be able to strike quickly and carefully to do that while in a tree.
However, in captivity, you’ll be feeding your rainbow correctly sized pinkies/fuzzy mice all the way up to adult rats. Always use forceps or tongs to feed your rainbow boa. They can mistake your finger for a prey item and accidentally bite you. It hurts, I promise. Or you can use a feeding dish of some sort, like a clean plate or bowl, that will help prevent accidental bites. Make sure your snake can climb in and out of the dish/bowl easily.
Most keepers buy frozen prey items and thaw them out completely before feeding them to their snake. It’s very convenient, and you will have food on-hand without having to deal with traffic and the inventory that changes all the time at the pet store. As your snake gets older and larger and moves up to larger prey items, you may want to seriously consider offering freshly killed or frozen/thawed prey items.
Convenience aside, once prey items get to be about the size of a hopper mouse, they will try to fight for their lives, and the prey item can harm your snake. I had it happen to my Kingsnake once, and only once. I made the proper adjustments, and feedings went smoothly from then on. Frozen/thawed is more humane to the rodent, too, and no damage will come to your snake. Be sure to read the manufacturer’s directions on how they recommend thawing out their prey items. Do not ever microwave prey items. It’s a messy, gross clean up.
Hatchling rainbows should easily take one live pinkie mouse every 5 to 7 days. Juvenile and adult rainbows should take one properly sized rodent each week for its lifetime. After feeding, you will see a noticeable lump in your snake’s belly. Don’t be alarmed.
As the snake grows, so does the size/amount of the prey item. Always try to increase the size of the prey item first. If increasing the size of the prey item is not an option, then increase the amount. Not by much; just equal to the properly sized prey item. By way of examples, if your snake usually takes an adult mouse, then 2 fuzzies should be equal; if your snake usually takes a rat, then 2 adult mice should be fairly equal.
Always have a big water dish filled with clean water in the enclosure. Like most reptiles, rainbow boas will soak in it, drink from it, and go to the bathroom in it. No snake, or anything else for that matter, wants to or will drink poop water. Make sure the water dish or tub you use is not going to turn over on top of your snake and possibly hurt it while it’s climbing in or out. The size of the dish will need to grow as your snake grows, so you will need to periodically upgrade your rainbow’s water container.
Handling and Temperament
When you first bring home your new rainbow and place it into its new home, give it some time to adjust to the new environment. Don’t feed it or try to handle it for 3 or 4 days because there is a chance doing these things could hurt the process rather than help build bonds of trust between you and your snake.
Hatchling and young rainbows are nippy at first. Like most baby snakes, they think you may try to hurt or eat them. Once the snake realizes you are not going to hurt it, hand-taming should go smoothly and quickly. After the adjustment period, begin to handle your snake for short periods of time at first, about 10 to 15 minutes at a time.
Move confidently and smoothly when holding your rainbow. Jerky or fast movements won’t make your snake very happy. Always support your snake when handling it. Let it move between your fingers and around your wrists and arms, but keep your snake away from your face. You could startle it and risk getting a quick nip.
Use the hand-under-hand method for supporting your rainbow as it moves, and don’t hold too tightly; just firm enough to have a secure hold but not so tight to prevent the snake from moving or to hurt it. As time goes on, your rainbow boa will understand you aren’t going to hurt it and will relax more in your hands, and you will be able to handle it for longer and longer periods of time.
This care information is a brief overview of a subject that has been covered in many books by respected authors and on many breeder forums. For more information, please consult a specialized book, visit one of the breed-specific forums/message boards, or contact an expert in that particular field. Your new animal will thank you for it.