Epicrates cenchria, or rainbow boa constrictor, is a species of boa that is native to Central and South America. Another common name for this snake is the slender boa.
They are highly desirable pet snakes due to their stunning appearance. They inhabit tropical and sub-tropical forests and have particular heat and humidity requirements when kept in captivity.
Rainbow Boa Facts
Here are some fun and interesting facts about rainbow boas.
1) Not Rainbow-Colored
As the “rainbow” in their name implies, rainbow boas have a gorgeous iridescent sheen that makes it appear as if they have a rainbow coloring on their body. However, it’s not the color of their scales that give them a “rainbow” sheen.
This phenomenon is called structural coloration. Rainbow boas are covered with smooth scales that are iridescent and reflect hues of green, blue, and purple due to the presence of chemicals called purines in the cells of their epidermis.
Their bodies have tiny ridges going along the edges of their scale. As sunlight shines on the snake, its body radiates a rainbow hue.
2) Patterns Keep Enemies Away
Rainbow boas have bold colorations and patterns that help camouflage their bodies.
There are numerous color and pattern variations among the subspecies of rainbow boa. The Brazilian rainbow boa is brown or reddish-brown, with big black splotches down its back.
The busy patterns play a role in breaking up the outline of a rainbow boa’s body. This helps it camouflage itself in the forest floor or among the debris.
A rainbow boa’s patterning occurs in the dorsal surface, and it won’t have any blotches on its ventral surface. This is because its ventral surface is never exposed and thus, doesn’t need to be concealed.
3) Sexual Maturity Based on Length
In Brazilian rainbow boas, sexual maturity is determined by the length of the snake and not the age. Males breed at 4 feet and females at 4.5 feet.
Brazilian boas reach this length in 2.5 to 4 years of age. Gestation lasts for about 5 months.
4) Heat Vision
Rainbow boas, like other boa constrictors, have special pits that help them detect heat.
They can sense infrared thermal radiation, which is critical for their survival, as they’re nocturnal and need this to find warm-blooded prey in the night. Therefore, they don’t have to rely on their vision, hearing or olfaction when in total darkness.
Heat or infrared detection in rainbow boas is facilitated by a unique and specialized sensory structure known as the pit. It functions via a heat-sensitive calcium ion channel, called the TRPA1, which behaves as an infrared sensory particle in the pit organ.
According to PLoS One, a snake’s pit organ is remarkably sensitive and helps it detect changes in temperature as low as 0.003°C. Furthermore, these special biological sensors also allow rainbow boas to detect heat radiation at wavelengths between 5 and 30 μm from as far as a meter away.
Scientists previously believed that these pit organs evolved predominantly to help snakes detect prey. However, newer studies, such as the one published in the Journal of Experimental Biology, suggest that the pits may be a more general-purpose sensory structure.
Researchers found that the pits may also be used in thermoregulation, environmental temperature sensation, as well as predator detection.
5) Climb Using their Tails
Rainbow boas have prehensile tails that mediate their climbing. Although the rainbow boa isn’t primarily an arboreal (tree-living) species like its cousin, the emerald tree boa – it will readily climb bushes and trees while looking for food, if needed.
A report published in the journal, Functional Ecology, explains why certain animals have prehensile tails, specifically in arboreal species. In tall or elongate animals, such as the rainbow boa, gravity can cause significant restrictions in blood circulation while the snake climbs.
In ground-dwelling animals, climbing can generate pressure within blood vessels. This pressure can, in turn, result in blood pooling and edemas, as well as a reduction in blood volume in the head and major organs.
Arboreal snakes have many adaptations to counter the effects of gravity and changes in pressure in blood circulation. One of them is the nonconforming tissue compartments located in the snake’s tail.
Although rainbow boas are mostly found hunting on land, their prehensile tails allow them to catch their prey in trees when necessary.
6) Primitive Snakes
Like all other boa constrictors, rainbow boas belong to the Boidae family of nonvenomous, constrictor snakes that are also considered to be primitive according to some scientists.
They are primitive because they possess two lungs, unlike most snakes that have only one, as well as the remnants of two vestigial hind limbs and pelvic bones. These remnants of limbs look like rudimentary spurs on both sides of the snake’s cloaca.
7) More Active at Dusk and Night
Although most snakes, like the rainbow boa, are neither nocturnal nor diurnal, which means they can be active during the day, rainbow boas prefer to perform most of their hunts in the night for many reasons, some of which include:
- Presence of More Warm Blooded Prey. Their natural prey, such as warm-blooded possums, bats, rats, and mice are also active in the night. This gives them more opportunity to ambush their prey.
- Their Heat-Sensing Pits. A rainbow boa’s heat-sensing pit organs allow it to detect warm-blooded prey in the night. This gives rainbow boas an advantage over their prey and ensures that their ambush hunting is more successful than if they relied on their vision only. Scientists also explain that a rainbow boa’s night hunting technique is much more effective than the active foraging of faster diurnal snakes, such as brown snakes and taipans.
- Less Active Predators. Rainbow boas’ natural predators, such as birds of prey, are much less active in the night. This means they are much less likely to be hunted down at this time.
8) Eat Almost Anything
Don’t let the stunning and elegant exterior of a rainbow boa fool you. Rainbow boas are incredibly cunning and dangerous in the wild and can catch and kill just about anything they can find.
Rainbow boas are known to readily eat a large variety of birds, small mammals, amphibians and some forms of aquatic animals and lizards.
The bulk of a rainbow boa’s diet consists primarily of rodents, however. Young boa constrictors consume small mice, bats, birds, lizards and amphibians and the size of their meal increases as they grow older and bigger.
9) Non-Venomous Snakes
Rainbow boas are nonvenomous snakes that kill their prey via constriction.
A rainbow boa catches its prey by striking it and then grabbing it with its teeth. Instead of fangs, boas have small, hooked teeth that allow them to grab their prey while they squeeze one to death.
After grabbing its prey, the boa will then proceed to wrap itself around the animal. Each time the prey takes a breath, the boa will squeeze tighter. Like any other snake, the rainbow boas swallow their prey whole without chewing.
Boas have specialized jaws that separate partially, allowing them to consume prey that is larger than their heads. The rainbow boa’s teeth also help it force its prey down its throat and to its stomach.
10) Don’t Suffocate Their Prey
It is untrue that boas kill their prey by suffocating it. The unconsciousness and death caused by constrictor snakes, such as the rainbow boa, occur as a result of shutting off vital blood flow to the heart and brain – and not asphyxiation.
Another study by Boback et al., suggests that boas tend to strike the anterior portion (head and shoulders) of their prey and apply two or more coils around the prey’s thorax.
The alignment of these coils over the animal’s ribcage allows the boa to apply circumferential force to the vital organs directly while being able to monitor the prey’s heartbeat.
By observing the prey’s heartbeat, the snake can then measure its effort and determine whether it needs to squeeze tighter.
According to scientists, the “circulatory arrest” caused by a boa is much faster and a more efficient and definite approach to killing prey than previously studied.
11) Can Go Without Food for Months
Rainbow boas have slow metabolisms, which allow them to survive without eating for several weeks and even months. Snakes can bring down their metabolism by up to 70 percent.
This gives them a selective advantage because they can continue to grow in length despite not having access to any food.
12) Don’t Lay Eggs (Viviparous)
Unlike most snakes and other reptiles that hatch from eggs, female boa constrictors give birth to live young. In other words, they are viviparous, just like anacondas.
When a snake is viviparous, it means there is no egg involved in its reproductive process – unlike in the case of oviparous or ovoviviparous snakes that lay eggs or retain their eggs inside their bodies.
Rainbow boas nourish their babies inside them via a placenta and yolk sac, which are all coated in a clear tenuous membrane.
The babies grow and develop inside their mother for a few months and just before they’re ready to come out, the clear membrane envelope ruptures. This allows the female boa to give birth to fully-formed live young.
On average, a rainbow boa will give birth to 8 to 20 offspring at a time. Rainbow boas shed after 7 to 10 days of birth, after which, they will instinctively hunt for their first prey.
13) Ambush Hunters
Rainbow boas are ambush predators. This means they will often use a “sit and wait” approach until an appropriate prey comes along before striking them. However, they are also known to hunt actively, especially in areas with low concentrations of potential preys.
14) Brazilian Rainbow Boa is The Largest
The Brazilian rainbow boa or Epicrates cenchria cenchria is the largest recognized rainbow boa subspecies. It’s endemic to Central and South America and can grow up to 6 feet in length.
A Brazilian rainbow boa’s head is not unusually large, but it is much wider than the neck.
15) Birds Eat Them
Young rainbow boas are often preyed upon by birds of prey, such as eagles and hawks. They can be hunted by other larger reptiles, such as alligators as well.
However, after they reach their full length, they’re rarely preyed upon and can live up to 10 years in the wild or up to 30 years in captivity with proper care.
16) Risk of Dehydration
Overheating and dehydration are among the most common causes of death in rainbow boas.
Signs of dehydration in rainbow boas include:
- Incomplete sheds
- Dry, wrinkly scales
It’s is essential that you provide a water source that is big enough for your snake to soak in. Be sure there is enough fresh water for your snake to drink at all times. Change the water frequently to prevent it from stagnating and getting dirty.
17) Light is Key to Their Glow
One important feature that makes rainbow boas appealing is their iridescent glow. However, to ensure this glow is present, it’s vital you include a suitable light source in your snake’s enclosure.
Mount an overhead low wattage fluorescent light to create a gorgeous display of your snake. Note that rainbow boas are mostly nocturnal, so you will have to switch off the lights for an 8-12 hour night cycle.