The iridescent glow of a Brazilian rainbow boa, E. cenchria cenchria, is a sight to see!
Personally I think they are the most beautiful constrictor snake there is. In the wild they can be found in the Amazon River Basin. They range from Peru and Brazil, all the way to Colombia and Suriname.
Their docile nature, ease of care and unique look make them a favorite among intermediate leveled snake collectors and breeders.
Rainbow Boa Care
| Care Level: | Intermediate |
| Temperament: | Docile, somewhat shy, slightly defensive |
| Native To: | Amazon River Basin |
| Average Size: | 6-7 feet |
| Cage Requirements: | 60″ x 24″ x 24″ minimum |
| Temperature: | 82-88 degrees during the day. 78-82 degrees at night. |
| Humidity: | 80-100% |
| Preferred Food: | Small to medium sized rats |
| Feeding Frequency: | Varies based on age |
| Lifespan: | 20+ years |
How Big Do Brazilian Rainbow Boas Get?
Compared to other constrictors, BRBs are slender snakes and remain slim their entire lives.
At birth, Brazilian rainbow boas measure 8-12” in length, and are thinner than your fingers. Adults males typically grow to about 5 ½ to 6 feet in length. Females are slightly longer, and have more girth than males, but can be hard to distinguish by size alone. Overall, these snakes grow to an average of 6-7 feet, and weigh 8-9 pounds.
They are a snake that is long enough to look impressive, but small enough to not need help handling them.
Brazilian Rainbow Boa Housing Needs
The housing needs for rainbow boas are pretty moderate, though you can go as elaborate as you would like.
Maintaining a fairly high humidity as well as a hot side and cool side of your snake’s habitat is key.
As babies, rainbow boas require nothing larger than a 10 gallon aquarium. Once your boid reaches around 2 feet in length, you should move to a larger enclosure equal to a 20-30 gallon aquarium. At 4 feet in length, your snake should be moved to an adult sized enclosure. This should measure at least 60 inches long, 24 inches wide and approximately 24 inches tall.
It’s at this point where many collectors consider a custom built enclosure not only for price, but for aesthetics as well.
You may want to consider starting out with an adult sized enclosure from the beginning.
Many Brazilian rainbow boa owners elect to go with fairly elaborate setups, mostly due to the high humidity needs of this snake. Starting over with a new setup every year or so as your snake grows, can be a bit challenging.
Start off the right way, and avoid the “I’ll get to it some day” curse by jumping straight in to an adult sized enclosure right away.
Additional housing needs to consider.
In addition to the cage itself, you should also include at least one or two hide boxes, and possibly some foliage along with branches for your snake to climb.
Unlike the green tree python, which is strictly arboreal, Brazilian rainbow boas are semi-arboreal. They use the ground as well as trees. They do like to climb, and will take advantage of any branches you offer them. This has the added benefit of additional hiding spaces for your pet.
Brazilian Rainbow Boa Temperature
In the wild these snakes thrive in a rainforest with year round temperatures between 75 and 90 degrees.
Of course in nature, there may be some days or nights that are outside of this range, but in captivity these are the temperatures you want to strive for.
Adult Brazilian rainbow boas should be offered a temperature range of 82-88 degrees during the day. At night, temperatures can be dropped to between 78 and 82 degrees. Babies should be kept at the same day time temperatures, but night time should be closer to 82-85 degrees..
Some people like to offer a gradient, or a range of temperatures. One side of the enclosure kept at the higher end of the range while the other side is kept at the cooler end of the range is a common practice for many snake keepers.
I recommend this for many snake species. Due to the high humidity demands of the Brazilian rainbow boa, and its semi-arboreal nature however, you should be fine having a temperature in the range I suggested.
Your snake will find enough warm and cool pockets within its enclosure to satisfy its needs.
Brazilian Rainbow Boa Humidity
As rainforest inhabitants, these boids require a higher relative humidity than some other snake species.
Here’s how much humidity Brazilian rainbow boas need. Adult Brazilian rainbow boas do best when the humidity range is kept between 80% and 100%. Babies require a higher range, and should be kept between 90% and 100% humidity. Although these snakes can tolerate brief periods of lower humidity, you don’t want them to be below 70% for an extended period of time.
This is extremely important as health issues can arise if their humidity is not kept at adequate levels. The most common health concerns would be respiratory illnesses and problems shedding.
Here is an article I wrote on maintaining the perfect humidity for reptiles. The link will open a new tab so you won’t lose your place here.
Brazilian Rainbow Boa Lighting
As nocturnal animals, Brazilian rainbow boas get much of their vitamin D3 from the animals they eat. This is a vitamin provided from natural sunlight.
What lighting should you use for a Brazilian rainbow boa? One of the best parts of owning these snakes is their iridescent glow, so either regular or full spectrum fluorescent lighting is recommended. This will help bring out the shimmery rainbow effect these boids are known for, and will make your snake look more appealing.
These snakes do not absolutely have to have full spectrum lighting, but I prefer it.
Despite being nocturnal, they still receive natural sunlight in the wild, and I always try to duplicate their natural habitats. Plus it really does bring out the rainbow effect that everyone loves to see.
Living near the equator, rainbow boas receive about 12 hours of light and 12 hours of darkness year round. I suggest using a timer so you never have to worry about it.
Brazilian Rainbow Boa Substrate
There are several factors you need to look at when considering which substrate to choose.
Is it aesthetically appealing? Does it benefit the humidity? How easy is it to clean? Will it harm my snake? How easy is it to acquire?
All of these things must be considered when deciding which substrate is best for your and your snake. Therefore, all I can do is give you my personal preferences, as there is more than one good answer.
Brazilian rainbow boa substrate. Puppy pads are a solid choice for a Brazilian rainbow boa substrate. They do a great job retaining and slowly releasing moisture, which aids in maintaining a high humidity, and are easy to replace. Alternatively, you may choose to use a combination of top soil and other organics such as orchid bark, cypress mulch, or coconut husk.
For BRBs, it’s all about the humidity level. Everything else is secondary. Achieving the high levels required to meet this snake’s needs can be challenging, and you want every advantage you can get.
I personally prefer puppy pads, which I then hide with foliage and other décor, but ultimately the choice is yours. There are even some great pre-mixed reptile substrates available on the market.
Whatever your choice however, make sure your substrate is specifically for reptiles. Store bought wood like cedar or redwood shavings may contain chemicals that could be harmful to your snake.
Sphagnum moss is another great way to maintain a natural look while providing higher humidity.
Brazilian Rainbow Boa Feeding And Diet
In the wild these snakes eat a wide variety of prey including rodents, small mammals, birds, bats and even lizards. In captivity however, you will want to stick with rodents.
As a rule of thumb, you should feed your snake prey that is approximately as big around as your boa is at its widest point.
Here is a Brazilian rainbow boa feeding and growth chart you might find useful.
| Age | Weight | Food | Frequency |
|---|---|---|---|
| Babies | 15-13 grams | Hopper mice | 5 days |
| Yearlings | 150-180 grams | Hopper or small adult | 7 days |
| 1.5 years | 250-300 grams | Adult mice | 7-10 days |
| 2 years | 575-625 grams | Large adult mice or weaned rat | 10 days |
| 2.5 years | 725-775 grams | Large adult mice to small rats | 10-12 days |
| 3 years | 850-900 grams | Small rats | 14 days |
| 4+ years | 1200+ grams | Small to medium rats | 14-21 days |
I do want to point out that this chart is simply an approximate guide, and a conservative one.
Snakes will grow at different rates, and at different stages in their life. You could even have two siblings that experience different growth rates. They could each have growth spurts months apart from one another.
The size of food you use and the frequency of feedings will have a big impact on your boa’s growth rate. This means feeding larger food, and feeding more often will lead to faster growth. Smaller food and fewer feedings will result in more moderate growth.
It might be tempting to shoot for a bigger snake faster, but I have to caution against this.
Feeding, diet and the overall nutrition for your snake, have a direct impact on their health. Obesity is just as much a health concern for snakes as it is for humans and all other animals.
It is always advisable to work towards getting your snake to eat prekilled food.
In their natural habitats, rainbow boas are ambush hunters.
They stay hidden, waiting for food to pass by, but can elect to not strike at the food if they don’t want to. They also have unlimited space to get away from aggressive animals if needed.
In an enclosure they are trapped with whatever else is in there.
Many rodents have sharp teeth and claws which can injure your snake when they fight back while being captured. They may also decide to attack the snake if it doesn’t kill the prey right away.
Never leave live prey with your snake unattended!
If you want to learn more about this, check out this article I wrote, Tips To Get A Snake To Eat Frozen Food.
Water
These snakes should be provided with clean, fresh water at all times. A bowl of water deep enough for your snake to submerse itself is ideal.
Keeping the bowl in the warm side of the enclosure can help raise humidity.
Brazilian Rainbow Boa Behavior
Brazilian rainbow boas are nocturnal snakes.
You might find that they begin to get more active an hour or two after the lights are turned out.
During the day they may stay under a hiding space. You will often see them in a very loose coil with their head sticking slightly out of the shelter as they wait for prey just as they would do in the wild.
These snakes are capable of climbing trees, but are most often on the ground.
Nonetheless it never hurts to offer them branches in their enclosure.
Besides adding more things for them to explore, it also adds to the overall look of the habitat you provide.
Brazilian Rainbow Boa Temperament And Handling
As babies, these snakes can be nervous and nippy.
After all, anything in the wild that would be reaching for this snake would most likely be trying to eat it!
Constant handling will calm them down over the course of a few short weeks. For the most part, Brazilian rainbow boas are pretty docile.
There are a few times when you should not handle your snake.
- Do not handle for 2-3 days after feeding. Even if they are accustomed to being handled, it still stresses the snake out to a certain degree. Scared snakes often regurgitate their food, so you want to give it time to digest.
- No handling during feeding times. Obviously you don’t want to be touching your snake when there is food in the cage, but you should also avoid contact with it when it can smell prey either in the air or on your hands.
- Avoid handling shortly before they give birth. Females can become restless a few days before giving birth, and can become slightly more aggressive. Check them of you have to, otherwise leave them alone.
Brazilian Rainbow Boa Breeding
Brazilian rainbow boas are actually quite easy to breed in captivity.
There is a book called The Reproductive Husbandry of Pythons and Boas by Richard A. Gross and Gerald Marzec which I highly recommend if you ever decide to breed these, or any other snakes.
In the wild these snakes have a breeding season based mostly on temperature changes. This is what you want to produce in captivity in order to induce them to breed.
The method I’ve used successfully is very easy, and should be done for both males and females at the same time.
Beginning in early November, start dropping the night time temperature by 2 degrees per week.
Every week, drop the night time temperature two more degrees until you reach a low of 68. During the day you should maintain a slightly lower than normal temperature, around 84 degrees.
Once you have reached a night time low of 68, maintain it at night for about three weeks.
After this three week period begin slowly raising the night time temperature back up by 2 degrees per week.
Continue doing this until you get back to your starting temperature, which I recommended earlier to be 80-84 degrees, and increase the daytime temperature back up to around 86-88.
After this period, begin looking for changes in your snakes.
Males may begin to quit feeding, and you may find that they shed their hemipenes skin.
Females on the other hand may begin to swell slightly and begin spending more time in the cooler section of their enclosure.
This is the time to put your male and female snakes together.
If you’re a beginner, you can put your snakes together before you begin seeing the signs. Just know that they may not do anything for a few weeks.
When they are ready, the male will begin to chase the female around the enclosure. This may last for several hours before she is ready to copulate.
Copulation may last for several hours, and can happen numerous times over the span of a few weeks.
Keep the snakes together until the female begins to show signs that she is gravid.
During the pre-breeding and breeding season, the female will usually move all around her enclosure.
Once she is gravid, you will find that she settles down and stays on the warmer side.
Some females will refuse food while gravid, but this is not an accurate indicator since others will eat all the way to the time when they give birth.
Females will typically have a post-ovulatory shed once they are gravid. The gestation period for these snakes is generally between 105-110 days after this shed.
Babies are born in individual amniotic sacs that they will break out of. It’s a messy ordeal as the mother gives birth to what appears to me a squirming pile of goo.
Babies will typically take their first meal the same day they are born. Pinky mice are the perfect size prey.
Brazilian Rainbow Boa Health Issues
There are no known inherent health issues with these snakes.
Most health problems arise from inadequate housing such as temperature or humidity too high or too low. Monitor these things at all times, and be sure to prevent drafts from getting into the enclosure.
Life Span
Brazilian rainbow boas do well in captivity and often live longer than 20 years.
Availability
These snakes are readily available through a wide variety of sources.
Many pet stores that sell snakes will have them. They are also found quite often at most reptile shows.
If neither of these options are available to you, there are many reputable breeders online.
Always check the reputation of any breeder you select!
Request to see pictures of the snake before you order it. You might also ask to see pictures of the parents to see if they are healthy.