Brazilian Rainbow Boa Care Sheet
Brazilian rainbow boas are a subspecies of Epicrates cenchria,
commonly known as Rainbow Boas. The range of brazilian rainbow boas is quite large. It
includes northern Peru and Brazil, southern Venezuela and Guyana and
much of Surinam and French Guiana. Although not endangered, due to
habitat destruction they are not common in their range. They are a
semi-arboreal, slender-bodied snake with an adult size of 5-7 feet,
females being slightly larger than males. Rainbow boas have beautiful
coloration ranging from a deep red to orange, sometimes brown, with
dark rings down their back, and several rows of dark spots along
their sides, the first row that is highlighted by bright,
Rainbow boas get their name from their incredible iridescence caused by
microscopic ridges on their scales that act like prisms to turn
light into rainbows.
Neonates and sub-adult Brazilian rainbow boas do very well housed in Rubbermaid
containers or similar. Adults need a minimum of somewhere around 4
to 6 square feet of caging. Substrates that Brazilian rainbow boas do well on include
sphagnum/peat moss, Care fresh, newspaper, and cypress mulch. I keep
mine on a layer of dimpled craft paper with a couple of layers of
newspaper underneath for added absorbency. Neonates require a much
higher humidity level than adults and can be housed successfully on
paper towels. With such high humidity comes mold, therefore
attention must be kept to maintaining very clean cages. Rainbow boas should
have free access to a large bowl of fresh water at all times (large
enough to soak in). As adults they will usually drink large amounts
of water and will not require nearly as high relative humidity in
their cages. Unless they are on several inches of loose substrate
that they can burrow in, they should also be provided with adequate
hiding spots. Though not an absolute necessity, perches and shelves
can be added to the enclosure.
Common mistake - using a fish tank with a screen top, This
will lose most of the humidity and dehydrate your Brazilian rainbow
boa. If not
corrected will lead to Upper respiratory problems and death.
Temperature and Humidity
Brazilian rainbow boas are more tolerant of lower ambient temperatures than many other boids, though they cannot tolerate excessive heat well. They should
have a temperature gradient of 75 - 83 degrees. Temperatures
exceeding 85 degrees can be fatal.
Common mistake - measuring temps at mid cage. Brazilian
rainbow boas will
spend most of their time on the cage floor, this is where the temps
should be measured.
Adult Brazilian rainbow boas require a minimum humidity level of 75%+. Should humidity
drop into the 60’s or 50’s for an extended period of time the
results can be respiratory infections, regurgitation, and death by
dehydration. For my adult rainbow boas I make a “damp hide” from a sweaterbox
size tub with two access holes in one side. I put 1 inch of peat
moss and one inch of green moss. Both nice and damp. They love to
hang out in there and come out to explore at night.
Neonate rainbow boas should be kept at or near 95%+ humidity. I accomplish this
with a fairly tight fitting shoebox rack. There’s always
condensation at the front. Temps for babies should be right around
Humidity is affected by two factors, evaporation and dissipation.
The larger surface area water dishes will evaporate more into the
air. By minimizing ventilation, you will keep that humidity in the
Common mistake - thinking daily spritzing will make up for
lack of natural humidity. If your enclosure is set up properly with
adequate water sources and minimal ventilation, spritzing is not
Brazilian rainbow boas can be somewhat nervous snakes. Babies are born striking at
anything, but with regular, gentle handling they can tame down quite
nicely to become acceptable pets. As baby rainbow boas, let them strike at
you, bite you and even chew on you. This will show them you will
not be chased away by those actions and they will soon learn the big
bad hand is nothing to be afraid of. Pick up the baby with a steady
non-tentative action. The baby will typically be coiled or piled in
one spot. Aim for the side away from the mouth and just do it! If
you are bit, there will be minimal pain and quite likely several
pinholes in your skin. Resist the urge to pull back, that will only
make it worse. Brazilian rainbow boa’s have teeth that curve backwards to hold onto
their prey. If you pull away, you will tear your skin and could
easily damage some of their teeth.
Rainbow boas are typically a more active snake when being held than your
average boa, seemingly always on the move. This is not to say that
they will not grip on to you tightly, these boas keep a good hold.
Be careful when holding not to startle them, as rainbow boas can nip
Brazilian rainbow boas are voracious feeders that feed primarily on rodents, birds,
lizards, and possibly aquatic life forms as well. In captivity they
eat mice and rats approximately the same size as the largest part of
the snakes girth. Neonates are born large enough to take hopper mice
and rat pinkies. If rainbow boas refuse food, their husbandry should
be carefully examined. Stress, poor husbandry, or illness is the
likely causes of a rainbow boa that refuses to eat.
Brazilian rainbow boa abies should be fed on a schedule of from once every four days to
once a week. Most of them will continue to feed even when they are
opaque prior to shedding. These snakes are born large enough to take
hopper mice as their first meal. Many of mine have done well
starting out on rat pinkies. A reluctant rainbow boa may be induced to
feed by placing it in a small tub or even a paper bag along with the
food item. Place the smaller container back in the secure cage in
case the baby escapes and leave it for an hour, if still not eating,
can be left overnight.
Common mistake - feeding pinky mice to baby Brazilian rainbow
boas. If you have
an unlimited source of pinky mice then go ahead but be prepared to
feed several to each baby at each feeding.
A mouse pinky will make a very small lump in a baby Brazilian
rainbow boa and be
digested down so that the lump is no longer externally visible
within 24 hours.
Brazilian rainbow boas will grow rapidly on one appropriately sized mice/rats a week.
Yearlings often grow to 48 inches in length though 36 to 40 inches
is more typical. Many two-year-olds are four and a half to five feet
long. Females and males are not significantly different in size.
Adult males can do well on 20 medium sized rats per year. A breeding
female will require two to three times as much to eat.
Brazilian rainbow boas are often overfed to obesity in captivity as adults. At 2', the
snake is large enough for pinkie rats and jumper mice. At 3', it is
capable of consuming adult mice and young rats. Feed at least once
every 10 days, when the snake begins feeding on large meals such as
rats feeding can occur less frequently. Avoid handling after a
sizable meal; it is stressful and may cause regurgitation. Rainbow
boas can be conditioned to accept pre-killed or thawed warmed
rodents at feed time. This technique is safer, than feeding live
rodents since this prevents the snake from being bitten by a rodent.
Live feeders should be avoided except for the few (very few) snakes
that will not eat anything else. Never leave a live rodent in the
with a snake unattended. A rodent can cause serious damage to your
Never handle rodents and then handle a snake; you may be mistaken as
food. Develop proper feeding habits. As the rainbow boa grows it may be
wise to feed the snake only dead rodents and move it to a feeding
container prior to food offering. If moved to a feeding container
for all feedings it may become conditioned not to expect food while
in its' cage. This may reduce the possibility of being mistaken as a
food item by an over zealous feeder. Best method is to place dead
rodent in container and let snake discover it, encourages gentle
food acquisition. Maintain accurate feeding and health records.
Shedding is dependent on the animal's growth rate and condition and
may occur every 3 - 6 weeks. They may refuse feeding attempts while
shedding. Increase the humidity as a rainbow boa approaches a shed, this
helps to avoid dry shed. With proper humidity, the shed should come
off without shredding. Can easily get torn but should not be
tattered. If the rainbow boa is having a bad shed where parts are stuck
on, wet a pillowcase, put the rainbow boa in the pillowcase and tie knot in
pillowcase to prevent snake from getting out. Place pillowcase back
in enclosure at a neutral temp location and leave for a couple of
hours. If still not fully shed, you can continue pillow case
Brazilian rainbow boa breeding practice is similar to that of the common boa. They can
produce litters with up to 35 young. They can be bred as early as
2.5 years providing they are meet minimum size and weight
requirements of 5+ feet and weighing more than 3.5 pounds for
females. Another six inches of length and pound of weight is more
appropriate and should produce a larger first litter with less
strain on the snake. Males should be 5 feet and 2.75 pounds, though
many are this size at 30 months, they usually won’t breed until 42
months. They should not be bred unless they are extremely healthy,
as breeding takes a lot out of them.
Cooling is necessary for successful production of egg and sperm
cells. Breeding may be induced by night time temperature drops down
to 68 - 72F and daytime temperatures in the low 80's. Reduction of
light cycle from 12 - 14 hours to 8 hours and misting the animals
with warm water prove beneficial. Brazilian rainbow boas will usually begin breeding
within a few weeks of being warmed back up after the cooling period.
Females will show a very marked mid body ovulatory lump for several
hours. This lump is usually not seen because it lasts for such a
short time. Most gravid females will refuse to feed. They will
sometimes take a very small prey animal while they are gravid. Many
females will become enormously large in the back half of their body
and look very emaciated in the front half late in the gestation.
Reproduction takes an extreme amount of energy and should only be
attempted with very healthy adults. Gestation lasts approximately
The female rainbow boa will often appear restless and cruise around the cage as
if looking for something for a day or two before laying. Laying
often occurs during weather changes. Female snakes should not be
disturbed while they are laying as this may cause them to interrupt oviposition which can lead to
a higher incidences of stillborn babies.
Female rainbow boas often eat recently laid infertile slugs. I have never
witnessed a female eating babies but recognize that the possibility
exists for a snake which is picking through a pile of live babies
and slugs to possible devour a newborn baby accidentally. For this
reason I try to remove the babies from the mother soon after they
Baby Brazilian rainbow boas are born in litters of two to thirty five. A typical
litter contains twelve to twenty five babies. Babies are born 15-20
inches, and show pale, washed out coloration. The babies will
color up significantly over the first few sheds. Ultimate coloring
can take 18 months to show.
Most babies start out striking at anything that moves, it’s either
food or needs to be chased away. They can be readily tamed with
direct, calm handling gently and regularly over the first few weeks.
They will often eat before they have shed. The first shed usually
occurs after 10 to 14 days from birth.
They need to be kept at temperatures near 77 degrees and in high
humidity. Temperatures above 85 degrees can cause fatalities in
Brazilian rainbow boas. Baby Brazilian rainbow boas require humidity above
70 percent. They will do well kept individually in plastic shoeboxes
until they are about 24 inches long and can then be moved into
larger plastic storage containers or box type cages.
Brazilian rainbow boa are difficult to sex based on visible external differences
until they are about three years old. Young ones can be sexed by
probing. Females will probe a distance of two to four subcaudal
scales and males will probe to a depth of eight to twelve subcaudal
scales. They can also be sexed by palpitation or popping. All three
methods require someone experienced in sexing snakes. Adult males
have substantially larger spurs along the side of the vent and also
have noticeably thicker bases of their tails due to the invaginated
hemipenes. After about eight years of age the heads of both sexes
are noticeably larger than on nearly similar sized young adults.
This phenomenon of the enlarged head on older animals seems to be
more pronounced on red and orange animals than on brownish
specimens. This phenomenon also occurs with older Peruvian rainbow
There are an increasing number of Brazilian rainbow boa morphs being discovered.
Though many of them are still unproven, current Brazilian rainbow
boa morphs include
but not limited to:
Anerythristic - lack or red pigmentation, results in a brown or
taupe with white crescents.
Hypomelanistic - reduction of melanin resulting in a snake with
brown orange and yellow patterning and significantly lighter
Bullseye - Side crescents where some degree of full circling occurs
with dark center.
Eclipse - Side blotches (oceli) where there is little to no
Blush - Side oceli where the crescent color is speckled through the
Striped (dorsal) - striping down the back.
Striped (lateral) - merging of individual oceli to make lateral
stripes on the sides.
Clown - large oversized oceli
Calico - white scales typically outlining the dorsal patterns
Albino - Lack of melanin
(or lack of expressing melanin) resulting in a white snake with
orange markings. Very secretive and not available at this time.