Boa Constrictor Facts

Scientific Name: Boa constrictor

Boa constrictor
Boa constrictor.

 Paul Starosta/Corbis Documentary/Getty Images

Boa constrictors are reptiles and reside mainly in Central and South America. Their scientific name, Boa constrictor, is derived from the Greek words meaning type of snake (boa) and to grasp (constrictor). They are known for their gigantic size and for killing their prey by squeezing them to death with their muscular bodies.

Fast Facts: Boa Constrictor

  • Scientific Name: Boa constrictor
  • Common Names: Red tailed boa, boas
  • Order: Squamata
  • Basic Animal Group: Reptiles
  • Distinguishing Characteristics: Large, heavy-bodied, beige blotches on brown body
  • Size: 8-13 feet in length
  • Weight: 20-100 pounds
  • Life Span: 20-40 years
  • Diet: Carnivore
  • Habitat: Tropical forests, grasslands
  • Conservation Status: Least concern
  • Fun Fact: Boas are excellent swimmers, but they avoid water as much as possible

Description

Boa constrictors are non-venomous snakes best known for their large size and for squeezing their prey to death. They can climb surfaces well, swim, and travel up to speeds of one mile per hour.

These reptiles have a life span of roughly 30 years, but the oldest ones have lived to 40 years. They can grow up to 13 feet in length and weigh from 20 to 100 pounds. The colors of their skin, such as pinkish-tan with patterns of brown and red, help to camouflage them well in their environment.

Habitat and Distribution

Boa constrictors live in Central and South America in habitats such as tropical forests, savannas, and semi-deserts. Boas hide in the burrows of rodents at ground level during the day to rest. They are also semi-arboreal and spend time in the trees to bask in the sun.

Diet and Behavior

Boa Constrictor Eating a Rat
The tail of a rat hangs from the mouth of a boa constrictor as it ingests the body of the rat.  Joe McDonald/Corbis Documentary / Getty Images

Boas are carnivores, and their diet consists mainly of mice, small birds, lizards, and frogs when they are young. As they mature, they eat larger mammals, such as rodents, birds, marmosets, monkeys, opossums, bats, and even wild pigs. 

At night, boas hunt using sensing pits on their face that allow them to detect their prey's body heat. Because they move slowly, boas rely on ambushing their prey; for instance, they may attack bats as they sleep in trees or as they fly by. They kill by using their powerful muscles to squeeze their victim's body. Scientists thought this squeezing suffocates their prey, but recent findings show that the powerful pressure from the snakes actually constricts blood flow in the animal. The pressure is so powerful that the prey’s heart is not able to overcome it and it dies within seconds. Once the animal is dead, these snakes swallow their prey whole. They have special tubes in the bottom of their mouth that allow them to breath as they eat their meal. Boa constrictors digest their food with their powerful stomach acids. After a large meal, they will not need to eat for several weeks.

Since they are nocturnal and solitary creatures, boas hide in rodent burrows during the day to rest, but may spend several hours in trees basking in the sun. During colder weather, they can become almost completely inactive.

Reproduction and Offspring

Boa constrictors reach mating age at around 3-4 years. The breeding period for them is during the rainy season. Males slither across the female’s body to stimulate the cloaca with his vestigial legs. Females produce anywhere from 20 to 60 young.

These reptiles are ovoviviparous, which means that they give birth to young that are fully formed. The female eats very little during the gestation period, which lasts roughly 100 days. When the eggs are ready to be born, they push out the cloaca and must break open the protective membrane they are still encapsulated in. At birth, the young are about 20 inches and can grow to 3 feet during the first several months of life. They can survive on their own and demonstrate natural instincts for hunting and hiding from predators.

Conservation Status

Boa constrictors are designated as least concern under CITES Appendix II, but they have not been assessed by the International Union for Conservation of Nature (IUCN).

The biggest threat to boas comes from humans who harvest them for their skin as part of the leather trade. In tropical parts of the Americas, people may bring boas into their homes to manage rodent infestations.

Species

There are over 40 species of boas. A few examples of species are the rubber boa (Charina bottae), the rosy boa (Charina trivirgata), and the red-tailed boa (Boa constrictor constrictor). Rubber boas live in western North America. As their name suggests, these boas have rubbery skin, and they burrow into the ground. The rosy boa’s habitat ranges from California and Arizona to Mexico. The red-tailed boa is the species of boa constrictor that is most commonly used as a pet.

Boa Constrictors and Humans

yellow boa constrictor
Workers displaying yellow boa constrictor at a festival in Bowie, Maryland.  Tom Carter/Photolibrary/Getty Images Plus

In the U.S., boa constrictors are often imported as pets and sometimes bred to produce more colorful snakes. While this pet trade may not pose a threat to boas, an unfortunate risk is that some owners simply release their pets into the environment because they do not realize how quickly these animals grow. This is particularly dangerous because boas can adapt well to new environments so long as the temperatures are conducive to them thriving. As a result, they can become an invasive species and pose serious threats to the new environment, which could lead to the disappearance of other indigenous species.

Sources

  • “Boa Constrictor.” Boa Constrictor, www.woburnsafari.co.uk/discover/meet-the-animals/reptiles/boa-constrictor/.
  • “Boa Constrictor.” Kids National Geographic, 1 Mar. 2014, kids.nationalgeographic.com/animals/boa-constrictor/. 
  • “Boa Constrictor.” Smithsonian's National Zoo, 28 Nov. 2018, nationalzoo.si.edu/animals/boa-constrictor. 
  • "Boa Constrictor Facts and Information." SeaWorld Parks, seaworld.org/animals/facts/reptiles/boa-constrictor/. 
  • Britannica, The Editors of Encyclopaedia. “Boa.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 14 May 2019, www.britannica.com/animal/boa-snake-family.