As its name suggests, the Boa Constrictor is a non-venomous constrictor snake found in North, Central and South America. It is a heavy-bodied snake that is commonly found in captivity.
There is currently nine recognised subspecies of Boa Constrictor including the Red-tailed Boa, Amaral’s Boa and the Argentine Boa. Some of these sub-species are controversial but they are separate in the context of geographical range.
This page will focus on the Common Boa (BCI) but the information provided can, in most parts be used for any of the other Boa Constrictor species.
There are also a number of different locales of BCI. These different locales produce very different snakes in terms of appearance and behavior. One such locale is the Hog Island Boa.
Boa Constrictor Description
The Boa Constrictor is a heavy bodied snake that usually reaches 7-9 foot in length. The size of this snake is highly variable amongst different subspecies and locales. As with most snakes females are generally larger than males.
The background of the snakes dorsal is usually cream to light brown in colour with dark saddle shaped markings running the length of its body. These markings become more prominent towards the tail of the snake.
The head of the snake is very distinctive. Most specimens have a dark line running through the middle of their head stretching from the snout to the back of the head. They also have a very distinctive dark pattern running from the front of each eye which extends towards the back of the snakes head, dropping down towards their jaw.
This snake does not have fangs. Instead they have rows of long teeth that curve backwards. They regularly loose teeth and replace them with new ones. Unlike most Boa’s, this snake does not have any heat sensing pits and it is believed that they do not have any thermo-sensing abilities.
As there is at least nine recognised sub-species of Boa Constrictor, along with a wide range of different morphs, the appearance and size of these snakes can vary greatly.
Natural Habitat and Distribution
Boa Constrictors can be found throughout Central and South America ranging from Mexico to Argentina. There are also sub-specie populations on the islands of St. Lucia and Dominica and on other Atlantic Islands stretching from Mexico to Argentina.
This snake prefers to live in Rainforests where the humidity is high. They are often found around rivers and other bodies of water and they are excellent swimmers. This environment also provides the snake with the best access to food as there is a large rodent and small mammal population in this ecosystem.
However, they have adapted to live in a wide range of habitats and can be found anywhere from woodlands to semi-arid deserts. For this reason, the Boa Constrictor is considered an invasive species and is capable of surviving well outside its natural range. An invasive population exists in the southern parts of the Florida Everglades. Florida is home to the largest number of invasive reptiles including the Burmese Python and the Green Iguana.
Boa Constrictor Behavior
A Boa Constrictors temperament can be highly variable depending on the individual snake and the particular sub-species. An aggressive Boa can be difficult to handle due to their large size and strength. Caution should be taken when handling any large snake regardless of their temperament. It is recommended to have at least one person with you when handling a big snake in case you get into trouble. A bite from a large snake can cause severe injury.
Colombian Boas tend to be relatively docile while Central American specimens tend to be more aggressive. Again this is highly variable from snake to snake and aggressive/defensive snakes can become more relaxed with regular handling.
It is recommended to purchase a juvenile snake. This gives you time to handle and interact with the snake before it grows large. The snake can become accustomed to you and will learn that you are not a threat to them.
Boa Constrictor Lifespan
Boas are amongst the longest living snakes with captive bred animals capable of living for 20 to 30 years with the correct care. There have been cases of captive Boas living for over 40 years although this is rare. The longest recorded lifespan of a Boa was over 43 years which was a snake that lived at the Philadelphia Geological Gardens. You should take their long lifespan into consideration before deciding to purchase one of these snakes.
Boa Constrictors as Pets
These snakes make great pets for the right owners. However, careful consideration should be given before deciding to purchase any reptile. There are a number of factors to take into consideration before deciding to purchase one of these snakes. A Boa Constrictor is a relatively large snake and will require a large enclosure to live in. You should also be aware that these snakes live for a long time.
Adult specimens require large food items so you must be prepared to feed the snake large rats and even rabbits, if the snake is large enough. If you can provide the above requirements and still feel a Boa is the snake for you then you should do as much research as you can on the particular species you choose. There are plenty of good care sheets on the internet. I suggest reading a number of these to see a range of recommendations from different people.
The Boa Constrictor is easier to manage than some of the larger constrictor snakes such as the Green Anaconda or the Reticulated Python. It is definitely a better choice to purchase a Boa Constrictor than these larger snakes if you are looking to start getting into bigger snakes.
Feeding a Boa Constrictor
In the wild, Boa Constrictors are ambush predators meaning they wait motionless for prey to wander pass before striking at it. However they are also known to be active hunters if food is scarce. Smaller Boas will eat mice, bats, birds, lizards and amphibians while larger specimens will eat larger mammals and birds.
In captivity, a juvenile Boa can be feed once a week on appropriately sized mice or rats. The food item should be about the same size as the largest part of the snake’s body. As the snake grows the size of the food items should increase. Adult Boas only need to be fed every 10 to 14 days on large rats or rabbits depending on their size.
Housing
Your Boa will require a large enclosure. Wooden terrestrial vivariums are ideal for Boas. Wood is an excellent insulator making it easier to control the temperature within the enclosure. Wood is also less expensive than glass vivarium’s which can be quite expensive for large snakes. Many Boa owners choose to build large custom enclosures for their snakes. However there are many commercially available wooden enclosures suitable for Boas.
A Juvenile Boa can be housed in a 3ft x 2ft enclosure. The snake will enjoy branches to climb on and a big water bowl to soak in. You should keep the water bowl away from the heat source to avoid the water getting too hot. This will also prevent the humidity in the tank from rising too high.
Adult Boas will need to be housed in larger enclosures so they have enough space to comfortably move around. The size of the enclosure should be proportional to the size of the snake with large females requiring setups measuring over 6ft in length. If possible, provide the Boa with a large enough water bowl to soak in. For large specimens this usually isn’t possible but if you have a bath at home they will enjoy the occasional soak.
Climbing branches are not necessary in an adult’s enclosure as they are less inclined to climb. Any Boa’s enclosure should include at least one hide at either end of the enclosure. This will allow the snake to feel secure at both the warm and cool end of the enclosure as they thermo-regulate.
Light and Heat
A Boa Constrictor does not require any additional artificial lighting. They are primarily a nocturnal species so UV supplementation isn’t required. All that is required for a Boa is natural light from a window to provide a day/night cycle.
The Boa should have a hot spot in the enclosure of about 90F. The cool end of the enclosure can be about 80F. This will allow the snake to thermo-regulate. A heat mat controlled by a good thermostat will be a sufficient heat source. Alternatively you can use overhead heat provided by a ceramic heat emitter or infrared bulb.
Bulbs should be concealed in a bulb guard to prevent the snake coming in contact with it. Heat bulbs can become very hot and can burn your snake. This is particularly important for Boa Constrictors as they lack heat sensing pits so they may not even know that they are getting burnt.
Substrate
Boas can be kept on a wide variety of substrates. Paper towel or newspaper can be used to provide a simple substrate that is easy to clean and replace. More aesthetic substrates such as aspen shavings can be used to give the enclosure a more naturalistic look. Sections of substrate can be removed once soiled and the entire substrate can be removed and replaced once a month when doing a deep clean of the enclosure.
Substrates such as Cypress Mulch or Coconut Bark can also be used but care should be taken to ensure these substrates don’t get too wet as they are very good at holding humidity. If a Boa is kept in a humid, damp enclosure they will be at risk of developing scale rot. The ideal humidity of a Boas enclosure should be about 60-70%.
Shedding
As with all snakes, a Boa Constrictor will shed its skin as it grows. Juveniles will shed every couple of weeks while adults will shed less frequently as they will be growing at a slower rate.
After a shed, check your Boa to ensure that there is no stuck shed. The most common place to find stuck shed is on the tip of the snake’s tail. This is often easy to remove by gently pulling off the stuck skin. If it doesn’t remove easily don’t force it. Soak the snake in warm water and try again. The stuck shed usually comes loose after a warm bath and will be easy to remove.
The most common reason for incomplete or stuck shedding is that the humidity in the enclosure is too low. Increasing the size of the water dish may help raise the humidity to an appropriate level. Alternatively you can move the water dish closer to the heat source. This will increase the temperature of the water which will mean the water will evaporate faster raising the humidity. Do not place the water bowl directly over the heat source as it could become too hot.
Adding a few branches to the enclosure may also aid the snake during the shedding process. You may notice that the snake will rub up against the branches to loosen and stuck shed.
Handling a Boa Constrictor
Handling sessions are an important part of owning a Boa. Even if your intentions are to keep the snake as a display animal, it is still important to handle the snake regularly so ensure they are used to interacting with you.
These snakes can grow quite large so it is important to start handling a Boa Constrictor when they are young. This will allow them time to build up a “trust” with you and minimise the chance of getting bitten when the snake is larger.
Many Boas will enjoy handling sessions and time out of their enclosure to explore. As with any large snake, it is important to have another person present when handling the snake in case something goes wrong.
Breeding Boa Constrictors
Boa Constrictors are relatively easy to breed in captivity providing a few simple steps are followed. First of all, you need to ensure that you have a healthy male and female of appropriate age to breed. Males are generally ready to breed once they are 18 months old and at least 4ft in length. Females should be at least 3 years old and 6ft in length before they are bred. A snake you plan to breed should be in good health and have good muscle tone.
It is important to know the sex of your snakes before thinking about a breeding project. The most common methods for sexing snakes is probing and popping. These methods of sexing snakes should only be done by someone with experience. If done incorrectly, you can seriously injure the snake. Ask for assistance from an experienced breeder if you have never sexed a snake before.
Probing involves inserting a metal probe into the snake’s cloaca moving it in the direction of the snake’s tail. The length the probe will insert will signify the sex of the snake. The probe will reach a depth of at least 6 sub-caudal scales in males while it will only reach about 2-4 sub-caudal scales in females.
Popping involves pushing the sex organ of the snake out through the cloaca to determine its sex. This is the hemipenes of the male and the musk gland of a female. This method involves placing your thumb and index finger above the snake’s cloaca and gently but firmly rolling your thumb towards the opening. If the snake is a male, you will see two hemipenes pop out while the musk gland will pop in the female. This method is more suitable for juvenile snakes as it is much easier to perform at this stage.
Boas should be put through a cooling cycle to stimulate breeding. During this time, night time temperatures can be reduced to about 75F while daytime temperatures should remain at about 85F. After about 3 weeks, the male can be introduced into the female’s enclosure.
Copulation isn’t always observed so continue introducing the male until you are sure that the job has been done. The female will increase in size as her body gets ready to ovulate. This can be a very noticeable bulge that is most prominent at the time of ovulation.
Most females will go off food once gravid but it is recommended to continue to offer them small meals every two weeks. Approximately 20 days after ovulation she will have her post ovulation shed. This is the best indication you will have as to when the babies will arrive. Babies are usually born about 100 days after the female goes through her post ovulation shed.
Baby Boas are typically born during the night with large females capable of having more than 50 babies although the average would be about half that. Baby Boas are born in an amniotic sack which they need to break through before they can take their first breath. Once you are sure that the female is finished giving birth, she should be removed from the enclosure. The babies can then be setup in individual enclosures. It is important to thoroughly scrub and sanitise the female’s enclosure before she is returned to it.
It is recommended to do as much research as possible before purchasing your reptile. If you are planning to purchase one of these snakes, read as many Boa Constrictor Care Sheets as you can in advance.