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Boa ConstrictorBoa constrictor

Every figure, record and mechanism on the Boa Constrictor profile was written from a source, and this is the working table behind it: 49 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

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Source
01

Smithsonian's National Zoo and Conservation Biology Institute

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

The page saysA nonvenomous snake that stops its prey's heart from pumping
The source saysit squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and outNote: tagline; nonvenomous: Smithsonian 'nonvenomous snakes'
The page saysDeserts, wet tropical forests, open savannas and cultivated fields, from northern Mexico to Argentina
The source saysBoa 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
The page saysLarge lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels
The source saysThey feed on large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels.Note: stats.diet
The page saysSqueezes just enough to stop the prey's heart pumping blood
The source saysit squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and outNote: stats.superpower
The page saysBoa constrictors are named for how they kill: constriction.
The source saysThe boa constrictor is named for its mode of predation: constriction.
The page saysThey are not venomous.
The source saysBoa constrictors are nonvenomous snakes
The page saysa boa strikes, grabs and squeezes until the prey is subdued, then swallows it whole
The source saysit strikes, grabs and squeezes until the prey is subdued. Once the prey is dead, the snake swallows it whole.
The page saysSmall hooked teeth give it a strong grip and keep the prey from wiggling free while the snake wraps its body around it.
The source saysTheir 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.
The page saysMany people believe boas crush bones or squeeze the lungs shut.
The source saysIt is commonly believed that boa constrictors subdue their prey by crushing their bones or squeezing their lungs to suffocate them
The page saysThe Smithsonian's National Zoo says recent research found something different.
The source saysrecent research on the constriction method revealed that these snakes employ a different strategy all together
The page saysThe snake squeezes just enough to cause "circulatory arrest" by cutting off the heart's ability to pump blood in and out.
The source saysit squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out
The page saysWith no blood reaching the brain, the animal dies.
The source saysBy keeping blood from flowing to the brain, the animal dies.
The page saysLarger members of the boa family have heat-sensitive pits on their heads, but boa constrictors do not.
The source saysLarger members of the Boidae family have heat-sensitive pits on their heads, but boa constrictors do not.
The page saysThey rely on their tongue and their excellent vision instead.
The source saysInstead, this animal relies on its tongue and its excellent vision to collect sensory information about its surroundings
The page saysIn most cases a boa is an ambush predator, which means it sits and waits for a meal to pass by.
The source saysIn most cases, they are ambush predators, meaning they sit and wait for a desirable prey item to pass by.
The page saysIf food is scarce, it becomes more active and goes looking.
The source saysif food is scarce, they become more active to seek out prey.
The page saysBoas hunt at night.
The source saysAs nocturnal animals, boa constrictors hunt at night.
The page saysThey eat large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels.
The source saysThey feed on large lizards, small or moderate sized birds, opossums, bats, mongooses, rats and squirrels.
The page saysA newborn boa is about 20 inches (50 cm) long.
The source saysThey range in length from 20 inches (50 centimeters) as newborns, or neonates, to 13 feet (3.9 meters) as adults.
The page saysAdults reach up to 13 feet (3.9 m)
The source saysto 13 feet (3.9 meters) as adults
The page sayscan weigh more than 100 pounds (45 kg) when full grown
The source saysThey can weigh more than 100 pounds (45 kilograms) when full grown.
The page saysBoa constrictors live 20 to 30 years in the wild.
The source saysBoa constrictors live 20-30 years in the wild.
The page saysboa constrictors are found from northern Mexico to Argentina
The source saysBoa constrictors are found from northern Mexico to Argentina.
The page saysOf all the boas, they can live in the greatest variety of habitats, from sea level to moderate elevation.
The source saysOf all the boas, constrictors can live in the greatest variety of habitats ranging from sea level to moderate elevation
The page saysThat includes deserts, wet tropical forests, open savannas and cultivated fields.
The source saysincluding deserts, wet tropical forests, open savannas and cultivated fields
The page saysThey are both terrestrial and arboreal
The source saysThey are both terrestrial and arboreal.
The page saysVery few cases of them attacking humans are known
The source saysthere are very few cases of them attacking humans
The page saysIn some places in South America they are even used to control rat infestations inside homes.
The source saysin some places in South America, boa constrictors are used to control rat infestations inside homes
The page saysA litter is 10 to 64 young, with an average of 25
The source saysLitter size: 10-64 young, average of 25
The page saysGestation takes 5 to 8 months
The source saysGestation: 5-8 months
The page saysthe mother gives birth to live young
The source saysFemales give birth to live, independent young.
The page saysA boa constrictor does not crush bones
The source saysIt is commonly believed that boa constrictors subdue their prey by crushing their bones or squeezing their lungs to suffocate them
The page saysIt squeezes just enough to stop its prey's heart from pumping blood
The source saysit squeezes just enough to cause a “circulatory arrest” by cutting off the ability of the heart to pump blood in and out
The page saysdangerLevel: Medium
The source saysthere are very few cases of them attacking humans
The page saystags: arboreal
The source saysThey are both terrestrial and arboreal.
The page saystags: ambush-predator
The source saysIn most cases, they are ambush predators, meaning they sit and wait for a desirable prey item to pass by.

Source
02

Animal Diversity Web, University of Michigan

Boa constrictor. Animal Diversity Web, University of Michigan.

The page saysa boa hanging from a branch can strike rapidly at an animal that passes by the branch
The source saysThey can rapidly strike at an animal that passes by a branch that they are suspended from, for example.
The page saysboas are generally 2 to 3 meters long
The source saysIndividuals are generally between 2 and 3 meters in length
The page saysthe maximum length reported was slightly over 4 meters
The source saysThe maximum length reported in B. constrictor was slightly over 4 meters.

Source
03

AnAge: The Animal Ageing and Longevity Database, Build 15, Human Ageing Genomic Resources

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

The page saysIn captivity, AnAge lists a maximum of 40.4 years.
The source saysMaximum longevity 40.4 years (captivity)

Source
04

Card et al. 2016

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

The page saysA 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.
The source saysmultiple lines of evidence for three widely-distributed clades roughly corresponding with the three primary land masses of the Western HemisphereNote: 2016 is the paper's publication year (reference metadata)
The page saysThe authors note that the snakes' different looks and many habitats suggest the genus may represent multiple species.
The source saysThe 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.
The page saysThere may be more than one species here.
The source sayscollectively suggest that the genus may represent multiple species

Source
05

Booth et al. 2011

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

The page saysone mother on record who had daughters with no father
The source sayswe provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced femalesNote: tagline
The page saysResearchers found evidence of facultative parthenogenesis in a Boa constrictor.
The source sayswe provide the first evidence of facultative parthenogenesis in a Boa constrictor
The page saysone mother producing viable female young with no father involved, and no experiment caused it
The source saysidentifying multiple, viable, non-experimentally induced femalesNote: fatherless: the paper's title; one mother: 'the offspring in relation to the mother'; non-experimentally induced = no experiment caused it
The page saysNo males were produced.
The source saysno males were produced

Source
06

Arzamendia et al. 2014

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

The page saysThe IUCN Red List rates the boa constrictor Least Concern.
The source saysIUCN Red List category: Least Concern (LC).
The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: stats.conservationStatus

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.