Learn all about the boa constrictor in our expert guide, including where they live and how much they weigh
All you ever wanted to know about the boa constrictor, a large non-venomous snake found in tropical Central and South America.
What do boa constrictors look like?
Boa means “large serpent” in Latin and assessing their size is certainly one way to help identify these snakes. Although their coloration varies depending on their habitat, boa constrictors have distinctive markings: they can be tan, green, red or yellow with bars, jagged lines, ovals, diamonds and circles.
They also have a muscular body, long and triangular head, jaw lined with small, hooked teeth and pelvic spurs.
How big are boa constrictors?
They weigh about 27kg and grow up to approximately 3.96m long (the largest recorded is 5.48m).
What do boa constrictors eat?
The ambush hunters eat mainly a variety of birds and mammals, including rats, monkeys and wild pigs.
How do boa constrictors detect their prey?
The snakes are active during the day and night, flicking their tongue to detect scent. Boa constrictors can also “convert the heat from organisms that are warmer than their ambient surroundings into electrical signals, allowing them to “see” in the dark”, reports the University of Houston.
Due to their size, boa constrictors tend to move slowly (about 1.6kmph) in a straight line (rectilinear progression) rather than in a wave-like movement (lateral undulation).
Do boa constrictors attack humans?
These snakes do not pose a threat to humans. In some places, they are used to control rodent populations on farms and in homes.
How do boa constrictors kill their prey?
The reptiles use over 100 small, hooked teeth (four rows in the upper jaw and two in the lower jaw) to grab hold of their prey and kill by constriction: squeezing their victim by wrapping their muscular bodies around them, reducing blood flow and causing death. The ambush hunters eat mainly a variety of birds and mammals, including rats, monkeys and wild pigs.
How does a boa constrictor eat large prey?
Once it has killed its prey, a boa constrictor swallows it whole (usually headfirst) by opening its jaw incredibly wide. A Journal of Experimental Biology (2022) study explains how Boa constrictor is able to breathe while constricting and feeding: the snake can adjust which region of its ribcage it uses to inhale.
Rhythmic muscular contractions pull the meal down the reptile’s throat and into its stomach where strong acids digest the food. A boa constrictor can go weeks without eating, especially after a big kill.
What’s the difference between a boa constrictor and an anaconda?
They both belong to the Boidae family, which also includes tree boas (genus Corallus) and species belonging to genus Epicrates (rainbow boa, for example).
Boa constrictors and anacondas (genus Eunectes) are good swimmers, but boa constrictors are much smaller than anacondas – the latter can grow up to 8.43m long and weigh as much as 227kg.
Anacondas spend most of their time in the water, whereas boa constrictors, despite being able to climb, are often found on the ground.
Where are boa constrictors found?
Boa constrictors occur in a wide variety of habitats, including forests, beaches, savannahs, swamps, scrublands and wetlands. They live throughout South America (Colombia, Ecuador, Peru, Venezuela, Guyana, Suriname, Brazil, Bolivia, Uruguay and Argentina); in the Lesser Antilles (Dominica, Saint Lucia and Trinidad and Tobago) and other islands along the coasts of South America. The snakes are known to rest in the inside of hollow logs or abandoned animal burrows.
How do boa constrictors reproduce?
Boa constrictor sexual maturity is not reached before the age of four. Females give birth after a four-to-six-month gestation period to live young (average litter size is 25), which measure about 0.6m each and spend most of their time in trees while they grow.
The reproductive cycle is seasonal, occurring after the rains have subsided but varies by region and subspecies. Males often gather around a female during courtship. Both sexes have pelvic spurs, which are the remnants of legs, although males’ pelvic spurs tend to be larger and are used for clasping during mating.
Can boa constrictors have young without mating?
Evidence shows that female boa constrictors can have babies on their own. In 2010, Biology Letters reported the first evidence of parthenogenesis in boa constrictors and the family Boidae. The young produced from this asexual reproduction were all female and retained their mother’s rare coloration.
How long do boa constrictors live?
Boa constrictors can live between 20 to 30 years in the wild
How many boa constrictor subspecies are there?
According to Molecular Phylogenetics and Evolution (2016), “numerous [Boa constrictor] subspecies have been described, yet there have been substantial differences in taxonomic recognition among studies”.
Mainland subspecies include B. c. amarali; B. c. constrictor; B. c. eques; B. c. imperator; B. c. longicauda; B. c. melanogaster; B. c. occidentalis and B. c. ortonii. Multiple island populations have also been identified as subspecies, including B. c. nebulosa from Dominica; B. c. orophias from St. Lucia; B. c. sabogae from the Pearl Islands of Panama and B. c. sigma from the Tres Marías islands of Mexico.
Does the boa constrictor face any threats?
This snake tends to be more vulnerable to predation when it is younger and smaller. According to the IUCN, Boa constrictor is of relatively low conservation concern. However, the species is hunted for its skin and meat, and for the exotic pet trade.
Its range does include several protected areas in South America, and it’s listed in CITES Appendix II (trade must be controlled). The subspecies Boa constrictor occidentalis is listed in CITES Appendix I (species threatened with extinction): a large amount of research on its ecology and conservation has been conducted in Argentina.