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What the sources say

Green AnacondaEunectes murinus

Every figure, record and mechanism on the Green Anaconda profile was written from a source, and this is the working table behind it: 51 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

Green anaconda. Smithsonian's National Zoo and Conservation Biology Institute.

The page saysUp to 550 pounds of camouflaged ambush predator
The source sayscan weigh 550 pounds (250 kilograms)
The page sayswith eyes and nostrils on top of its head
The source saysTheir nose and eyes are located on the top of their heads to help them see and breathe while swimming in the water.
The page saysthat kills with suffocating coils
The source saysuse their muscular bodies to suffocate the prey before swallowing it whole
The page saysFish, birds and small mammals as juveniles; deer, capybaras, caimans, tapirs and large birds as adults
The source saysJuveniles tend to eat fish, birds and small mammals. Adults are able to consume much larger animals, including deer, capybara, caimans and large birds.
The page saysIts eyes and nostrils sit on top of its head, letting a green anaconda "see and breathe while swimming in the water,"
The source saysTheir nose and eyes are located on the top of their heads to help them see and breathe while swimming in the water.
The page saysFemales are considerably larger than males, and can reach 30 feet (9 meters) long, 12 inches (30.5 centimeters) across and 550 pounds (250 kilograms)
The source saysFemales are considerably larger than males. They can reach lengths of 30 feet (9 meters), diameters of 12 inches (30.5 centimeters) and can weigh 550 pounds (250 kilograms).
The page saysThe average life span in the wild is about 10 years; anacondas live much longer in human care, with some reports of them reaching their late 20s
The source saysTheir average life span in the wild is about 10 years. However, they live much longer in human care, with some reports of anacondas living into their late 20s.
The page saysthough large prey carries a risk of injury
The source saysthey are careful to weigh the risk of injury with large prey
The page saysJuveniles tend to eat fish, birds and small mammals; adults can take much larger animals, including deer, capybaras, caimans, tapirs and large birds
The source saysJuveniles tend to eat fish, birds and small mammals. Adults are able to consume much larger animals, including deer, capybara, caimans and large birds.
The page saysGreen anacondas have slow metabolisms, and apart from breeding females, they only need to eat once every few weeks
The source saysGreen anacondas have slow metabolisms, and with the exception of breeding females, only need to eat once every few weeks.
The page saysMating generally runs from March to May, during the dry season
The source saysMating generally occurs from March to May during the dry season.
The page saysMales form groups of up to 13 around one female, a "breeding ball" in which they compete for access to her, and the mating can last up to a month
The source saysMales form groups of up to 13 snakes and mate with one female. They form a “breeding ball,” where the males surround the female and compete for access to her cloaca. The mating can last for up to a month
The page saysAfterward she may eat one or more of the smaller males, as she will not eat again during the seven-month gestation
The source saysthe female may consume one of more of the smaller males, as she will not eat again for the seven month gestation periodNote: source's own wording is 'one of more', a typo for 'one or more'
The page saysShe gives birth to live young in the water, 20 to 40 at a time, and the largest litter on record was 82
The source saysFemales give live birth in the water ... can give birth to 20-40 young ... The largest litter on record was 82 young.
The page saysGreen anacondas are native to the northern regions of South America: most abundant in Colombia's Orinoco basin, Brazil's Amazon basin and Venezuela's flooded Llanos grasslands, and also found in Ecuador, Peru, Bolivia, Guyana, Paraguay, French Guiana and Trinidad
The source saysnative to the northern regions of South America ... most abundant in the Orinoco basin in Colombia, the Amazon River basin in Brazil, and the flooded Llanos grasslands in Venezuela ... also found in Ecuador, Peru, Bolivia, Guyana, Paraguay, French Guiana, and Trinidad
The page sayshabitat loss, hunting and the international pet trade work against it
The source sayshabitat loss is a threat to green anacondas ... Green anacondas are also hunted by people ... these snakes are also captured for the international pet trade
The page saysDuring the mating season, males form groups of up to 13 around one female, called a breeding ball, in which they compete for access to her. The mating can last for up to a month.
The source saysMales form groups of up to 13 snakes and mate with one female. They form a “breeding ball,” where the males surround the female and compete for access to her cloaca. The mating can last for up to a month
The page saysSlow-moving rivers and streams, flooded Llanos grasslands, and rainforest swamps across the northern regions of South America
The source saysnative to the northern regions of South America ... the flooded Llanos grasslands in Venezuela ... generally live in tropical rainforests and tend to prefer shallow, slow-moving waters, such as streams, rivers and flooded grasslands
The page saysFemales are the larger sex. They can reach lengths of up to 30 feet (9 meters), a diameter of 12 inches (30.5 centimeters), and weights of up to 550 pounds (250 kilograms).
The source saysFemales are considerably larger than males. They can reach lengths of 30 feet (9 meters), diameters of 12 inches (30.5 centimeters) and can weigh 550 pounds (250 kilograms).

Source
02

San Diego Zoo Wildlife Alliance

Anaconda. San Diego Zoo Wildlife Alliance.

The page saysA stretchy, ligament-hinged jaw that swallows prey whole
The source saysJaws attached by stretchy ligaments allow the snake to swallow its prey whole.
The page saysSan Diego Zoo calls South America's green anaconda "the heaviest snake in the world."
The source saysSouth America’s green anaconda is the heaviest snake in the world
The page saysIts jaws are attached by stretchy ligaments, which let it swallow prey whole
The source saysJaws attached by stretchy ligaments allow the snake to swallow its prey whole.

Source
03

Animal Diversity Web, University of Michigan

Eunectes murinus (Anaconda, Green Anaconda). Animal Diversity Web, University of Michigan.

The page sayscamouflaged ambush predator
The source saysGreen anacondas rely on stealth and ambush techniques as they hunt. Their body pattern provides effective camouflage
The page saystapirs
The source saysfeed on large prey ... South American tapirs (Tapirus terrestris)Note: ADW lists the tapir among named large prey items; Smithsonian's list does not name it
The page saysdeath comes from suffocating coils, or just as often, from drowning near water
The source saysSince feeding usually takes place near the water, prey are as likely to die from drowning as from constriction.
The page saysits camouflage leaves a submerged anaconda virtually invisible from a short distance away
The source saysTheir body pattern provides effective camouflage, allowing a submerged anaconda to be virtually invisible from a short distance away.
The page saysIt grabs hold of prey with needle-sharp, curved teeth, throws coils of muscle around the body, and death follows from respiratory arrest and circulatory failure
The source saysrestraining their prey using their needle-sharp, curved teeth for a secure grip while killing it by constriction ... Death occurs through respiratory arrest and circulatory failure.
The page saysFeeding usually happens near water, where prey are as likely to drown as to die from constriction
The source saysSince feeding usually takes place near the water, prey are as likely to die from drowning as from constriction.
The page saysand headfirst
The source saysingests its victim headfirst
The page saystapirs
The source saysfeed on large prey ... South American tapirs (Tapirus terrestris)Note: ADW lists the tapir among named large prey items; Smithsonian's list does not name it
The page saysIt seizes prey with sharp, curved teeth, then coils around the body; death follows from respiratory arrest and circulatory failure. It usually feeds near water, where prey are just as likely to drown as to die from the squeeze.
The source saysrestraining their prey using their needle-sharp, curved teeth for a secure grip while killing it by constriction ... Death occurs through respiratory arrest and circulatory failure. Since feeding usually takes place near the water, prey are as likely to die from drowning as from constriction.
The page saysthrows coils of muscle around its prey and kills it by constriction, through respiratory arrest and circulatory failure
The source saysrestraining their prey using their needle-sharp, curved teeth for a secure grip while killing it by constriction ... Death occurs through respiratory arrest and circulatory failure.Note: vibe.reason (#692/#693)

Source
04

USGS Nonindigenous Aquatic Species Database

Eunectes murinus (Linnaeus, 1758). USGS Nonindigenous Aquatic Species Database.

The page saysThe US Geological Survey, citing a 2000 study, reports that breeding females are at least five times the size of breeding males
The source saysBreeding females are at least five times the size of breeding males (Rivas 2000).
The page saysdangerLevel: High
The source saysThere are few records of attacks on humans, and no well-documented deathsNote: #670: no source records a death, so not Deadly; Smithsonian: 'Reports of anaconda attacks on humans are rare'

Source
05

Shibata et al. 2017

Shibata et al. (2017). Facultative parthenogenesis validated by DNA analyses in the green anaconda (Eunectes murinus). PLOS ONE.

The page saysA mother without a mate at Ueno Zoo in Tokyo had been kept alone for eight years and two months
The source saysa female anaconda isolated from other individuals for eight years and two months at Ueno Zoo, Japan.
The page saysUeno Zoo in Tokyo
The source saysbrought to Ueno Zoo, Tokyo, Japan
The page sayswhen she died of pneumonia in 2015
The source sayson November 8, 2015, she died of pneumonia.
The page saysHer autopsy found two almost fully developed but dead female offspring
The source saysAutopsy revealed two developed fetuses ... Both fetuses were almost fully developed but dead ... Examination of gonads by dissection confirmed both to be female.
The page saysat all 16 informative DNA markers they carried only her alleles and no paternal ones
The source sayswe analyzed 18 microsatellite markers of which 16 were informative. We observed only maternal alleles and no paternal alleles for all 16 markers.
The page saysThe researchers call it the first case of parthenogenesis in Eunectes validated by DNA analysis
The source saysThis is the first case of parthenogenesis in Eunectes to be validated by DNA analysis
The page saysA female caught in Guyana
The source sayswas caught in Guyana and brought to Ueno Zoo, Tokyo, Japan
The page sayslived alone at a Tokyo zoo for over eight years
The source saysa female anaconda isolated from other individuals for eight years and two months at Ueno Zoo, Japan.Note: eight years and two months; Tokyo from 'brought to Ueno Zoo, Tokyo, Japan'
The page saysWhen she died, she was carrying two female young
The source sayson November 8, 2015, she died of pneumonia. Autopsy revealed two developed fetuses ... Both fetuses were almost fully developed but dead ... Examination of gonads by dissection confirmed both to be female.
The page sayswhose DNA, at 16 markers, showed no sign of a father
The source sayswe analyzed 18 microsatellite markers of which 16 were informative. We observed only maternal alleles and no paternal alleles for all 16 markers.
The page sayswhich the researchers say is the first DNA-confirmed case in the anaconda genus
The source saysThis is the first case of parthenogenesis in Eunectes to be validated by DNA analysis

Source
06

Rivas et al. 2024

Rivas et al. (2024). Description of the Northern Green Anaconda (Eunectes akayima sp. nov. Serpentes; Boidae): What Is in a Name? Diversity.

The page saysIn 2024 Rivas and colleagues named the northern green anaconda, Eunectes akayima, as a separate species, saying the two separated about 10 million years ago
The source sayswe previously documented the existence of two distinct species, Eunectes akayima sp. nov. and Eunectes murinus (Linnaeus, 1758), that separated approximately 10 million years agoNote: 2024 is the reference's own year; the title is 'Description of the Northern Green Anaconda (Eunectes akayima sp. nov.)'
The page saysand differ notably in how much bigger females grow than males
The source sayssupported by a notable difference in sexual size dimorphism (SSD) intensity between the two species
The page saysthe describers' later paper says it rectifies earlier oversights in that description
The source saysThis paper also rectifies earlier oversights in the description of the new species

Source
07

Vásquez-Restrepo, Alfonso-Rojas & Palacios-Aguilar 2024

Vásquez-Restrepo, Alfonso-Rojas & Palacios-Aguilar (2024). On the validity of the recently described northern green anaconda Eunectes akayima (Squamata, Serpentes). Bionomina.

The page saysOther researchers argued that the original description broke the International Code of Zoological Nomenclature and sank the new name as a synonym
The source saysthe article in question violates fundamental aspects of the International Code of Zoological Nomenclature ... leading to the synonymizing of the recently described species

Source
08

Calderón et al. 2021

Calderón et al. (2021). Eunectes murinus. The IUCN Red List of Threatened Species 2021: e.T44580041A44580052.

The page saysThe IUCN lists Eunectes murinus as Least Concern
The source saysIUCN Red List category: Least Concern (LC).Note: category read through GBIF's copy of the Red List; iucnredlist.org refuses scripts

Source
09

Rivas 2023

Rivas (2023). What can studying anacondas tell us about Titanoboa cerrejonensis? Exploring the life of an extinct giant snake using an extant pretty big snake. The Herpetological Journal.

The page saysweightKg: 22.5
The source saysMass (NP) 22496.4 14699.4 54000 4700 104Note: task #739; mean mass of 104 non-pregnant adult females, 22,496 g, from 823 Llanos anacondas caught 1992 to 2014 (Table 1, masses in grams), rounded to 22.5 kg. Medium class (10 to 100 kg). Males in the same table average 5,678.6 g (Light), and the whole sample 11,437.1 g (Medium)

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.