---
title: "What the sources say about the Boa Constrictor | AnimalTracks.wiki"
description: "49 claims from the Boa Constrictor profile, each beside the words of the source that backs it."
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---

# What the sources say about the Boa Constrictor (*Boa constrictor*)

> 49 claims from the Boa Constrictor profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Boa Constrictor](https://animaltracks.wiki/animals/boa-constrictor/)

## Boa constrictor. Smithsonian's National Zoo and Conservation Biology Institute.

https://nationalzoo.si.edu/animals/boa-constrictor

| The page says | The source says |
| :--- | :--- |
| A nonvenomous snake that stops its prey's heart from pumping | it squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out (note: tagline; nonvenomous: Smithsonian 'nonvenomous snakes') |
| Deserts, wet tropical forests, open savannas and cultivated fields, from northern Mexico to Argentina | Boa constrictors are found from northern Mexico to Argentina. Of all the boas, constrictors can live in the greatest variety of habitats ranging from sea level to moderate elevation, including deserts, wet tropical forests, open savannas and cultivated fields. (note: stats.habitat) |
| Large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels | They feed on large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels. (note: stats.diet) |
| Squeezes just enough to stop the prey's heart pumping blood | it squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out (note: stats.superpower) |
| Boa constrictors are named for how they kill: constriction. | The boa constrictor is named for its mode of predation: constriction. |
| They are not venomous. | Boa constrictors are nonvenomous snakes |
| a boa strikes, grabs and squeezes until the prey is subdued, then swallows it whole | it strikes, grabs and squeezes until the prey is subdued. Once the prey is dead, the snake swallows it whole. |
| Small hooked teeth give it a strong grip and keep the prey from wiggling free while the snake wraps its body around it. | Their teeth are small and hooked, which allows for a strong grip when the snake strikes its prey and prevents the prey from wiggling free while the snake wraps its powerful body around the victim. |
| Many people believe boas crush bones or squeeze the lungs shut. | It is commonly believed that boa constrictors subdue their prey by crushing their bones or squeezing their lungs to suffocate them |
| The Smithsonian's National Zoo says recent research found something different. | recent research on the constriction method revealed that these snakes employ a different strategy all together |
| The snake squeezes just enough to cause "circulatory arrest" by cutting off the heart's ability to pump blood in and out. | it squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out |
| With no blood reaching the brain, the animal dies. | By keeping blood from flowing to the brain, the animal dies. |
| Larger members of the boa family have heat-sensitive pits on their heads, but boa constrictors do not. | Larger members of the Boidae family have heat-sensitive pits on their heads, but boa constrictors do not. |
| They rely on their tongue and their excellent vision instead. | Instead, this animal relies on its tongue and its excellent vision to collect sensory information about its surroundings |
| In most cases a boa is an ambush predator, which means it sits and waits for a meal to pass by. | In most cases, they are ambush predators, meaning they sit and wait for a desirable prey item to pass by. |
| If food is scarce, it becomes more active and goes looking. | if food is scarce, they become more active to seek out prey. |
| Boas hunt at night. | As nocturnal animals, boa constrictors hunt at night. |
| They eat large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels. | They feed on large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels. |
| A newborn boa is about 20 inches (50 cm) long. | They range in length from 20 inches (50 centimeters) as newborns, or neonates, to 13 feet (3.9 meters) as adults. |
| Adults reach up to 13 feet (3.9 m) | to 13 feet (3.9 meters) as adults |
| can weigh more than 100 pounds (45 kg) when full grown | They can weigh more than 100 pounds (45 kilograms) when full grown. |
| Boa constrictors live 20 to 30 years in the wild. | Boa constrictors live 20-30 years in the wild. |
| boa constrictors are found from northern Mexico to Argentina | Boa constrictors are found from northern Mexico to Argentina. |
| Of all the boas, they can live in the greatest variety of habitats, from sea level to moderate elevation. | Of all the boas, constrictors can live in the greatest variety of habitats ranging from sea level to moderate elevation |
| That includes deserts, wet tropical forests, open savannas and cultivated fields. | including deserts, wet tropical forests, open savannas and cultivated fields |
| They are both terrestrial and arboreal | They are both terrestrial and arboreal. |
| Very few cases of them attacking humans are known | there are very few cases of them attacking humans |
| In some places in South America they are even used to control rat infestations inside homes. | in some places in South America, boa constrictors are used to control rat infestations inside homes |
| A litter is 10 to 64 young, with an average of 25 | Litter size: 10-64 young, average of 25 |
| Gestation takes 5 to 8 months | Gestation: 5-8 months |
| the mother gives birth to live young | Females give birth to live, independent young. |
| A boa constrictor does not crush bones | It is commonly believed that boa constrictors subdue their prey by crushing their bones or squeezing their lungs to suffocate them |
| It squeezes just enough to stop its prey's heart from pumping blood | it squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out |
| dangerLevel: Medium | there are very few cases of them attacking humans |
| tags: arboreal | They are both terrestrial and arboreal. |
| tags: ambush-predator | In most cases, they are ambush predators, meaning they sit and wait for a desirable prey item to pass by. |

## Boa constrictor. Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Boa_constrictor/

| The page says | The source says |
| :--- | :--- |
| a boa hanging from a branch can strike rapidly at an animal that passes by the branch | They can rapidly strike at an animal that passes by a branch that they are suspended from, for example. |
| boas are generally 2 to 3 meters long | Individuals are generally between 2 and 3 meters in length |
| the maximum length reported was slightly over 4 meters | The maximum length reported in B. constrictor was slightly over 4 meters. |

## AnAge entry for Boa constrictor. AnAge: The Animal Ageing and Longevity Database, Build 15, Human Ageing Genomic Resources.

https://genomics.senescence.info/species/entry.php?species=Boa_constrictor

| The page says | The source says |
| :--- | :--- |
| In captivity, AnAge lists a maximum of 40.4 years. | Maximum longevity 40.4 years (captivity) |

## Card et al. (2016). Phylogeographic and population genetic analyses reveal multiple species of Boa and independent origins of insular dwarfism. Molecular Phylogenetics and Evolution.

https://doi.org/10.1016/j.ympev.2016.05.034

| The page says | The source says |
| :--- | :--- |
| A 2016 genetic study found three widely distributed clades, or branches of the family tree, roughly matching the three main land masses of the Western Hemisphere. | multiple lines of evidence for three widely-distributed clades roughly corresponding with the three primary land masses of the Western Hemisphere (note: 2016 is the paper's publication year (reference metadata)) |
| The authors note that the snakes' different looks and many habitats suggest the genus may represent multiple species. | The distinct morphological traits and color patterns exhibited by these snakes, together with the wide diversity of ecosystems they inhabit, collectively suggest that the genus may represent multiple species. |
| There may be more than one species here. | collectively suggest that the genus may represent multiple species |

## Booth et al. (2011). Evidence for viable, non-clonal but fatherless Boa constrictors. Biology Letters.

https://doi.org/10.1098/rsbl.2010.0793

| The page says | The source says |
| :--- | :--- |
| one mother on record who had daughters with no father | we provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced females (note: tagline) |
| Researchers found evidence of facultative parthenogenesis in a Boa constrictor. | we provide the first evidence of facultative parthenogenesis in a Boa constrictor |
| one mother producing viable female young with no father involved, and no experiment caused it | identifying multiple, viable, non-experimentally induced females (note: fatherless: the paper's title; one mother: 'the offspring in relation to the mother'; non-experimentally induced = no experiment caused it) |
| No males were produced. | no males were produced |

## Arzamendia et al. (2014). Boa constrictor. The IUCN Red List of Threatened Species 2021: e.T197462A2486405.

https://doi.org/10.2305/iucn.uk.2021-2.rlts.t197462a2486405.en

| The page says | The source says |
| :--- | :--- |
| The IUCN Red List rates the boa constrictor Least Concern. | IUCN Red List category: Least Concern (LC). |
| Least Concern | IUCN Red List category: Least Concern (LC). (note: stats.conservationStatus) |