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What the sources say

BoomslangDispholidus typus

Every figure, record and mechanism on the Boomslang profile was written from a source, and this is the working table behind it: 60 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

Luiselli et al. 2021

Luiselli et al. (2021). Dispholidus typus. The IUCN Red List of Threatened Species 2021: e.T190603A15357215.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: category read through GBIF's copy of the Red List, per docs/fact-check.md; anything else from the assessment is a hand check

Source
02

Animal Diversity Web, University of Michigan

Dispholidus typus (boomslang). Animal Diversity Web, University of Michigan.

The page saysKaroo scrub, arid savanna, and east African lowland forest
The source sayscommonly found in karoo scrubs, arid savannas, and east African lowland forests
The page sayschameleons and other tree lizards, plus frogs and occasional eggs
The source saysmain diet consists of small arboreal lizards and frogs, including chameleons. Occasionally, they feed on small mammals, birds, the eggs of reptiles and birds
The page saysIt's most common in Eswatini, Botswana, Namibia, Mozambique and Zimbabwe
The source saysmost abundant in Swaziland, Botswana, Namibia, Mozambique, and ZimbabweNote: the source names Swaziland, the country's name until it was renamed Eswatini in 2018; same territory
The page saysrecorded as far north as Nigeria and southern Chad
The source sayshave been observed as far north as Nigeria and southern Chad
The page saysfavors karoo scrub, arid savanna and east African lowland forest, keeping mostly to low trees and shrubs
The source sayscommonly found in karoo scrubs, arid savannas, and east African lowland forestsNote: 'mostly to low trees and shrubs' from adw-boomslang: 'They mainly live in low-lying shrubs and short trees.'
The page saysruns 1.2 to 1.5 meters long, occasionally reaching 2 meters
The source saysAverage length of an adult is 1.2 to 1.5 meters ... Range length 1.2 to 2.0 m
The page saysMost snakes have poor eyesight
The source saysSnakes, in general, do not have well developed eyesight but are able to see movement and color.
The page saysSymptoms can take several hours to appear
The source saysThis slow-acting venom causes symptoms to start occurring in the victim several hours after contact
The page saystags: savanna
The source sayscommonly found in karoo scrubs, arid savannas, and east African lowland forestsNote: task #613
The page saystags: arid
The source saysKaroo scrubs are low-lying semi-desert areas unique to South Africa.Note: task #613; replaces desert. Arid is "dry scrublands and rain shadows"; desert's definition (extreme water scarcity, burrowing) fits neither a semi-desert scrub nor an arboreal snake
The page saystags: forest
The source sayscommonly found in karoo scrubs, arid savannas, and east African lowland forestsNote: task #613; replaces woodland, whose definition is temperate deciduous and mixed forest. East African lowland forest is tropical

Source
03

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

Dispholidus typus (Boomslang). AnAge: The Animal Ageing and Longevity Database, Human Ageing Genomic Resources.

The page saysThe record lifespan is 8.7 years, set in captivity
The source saysMaximum longevity 8.7 years (captivity)

Source
04

Pla et al. 2017

Pla et al. (2017). What killed Karl Patterson Schmidt? Combined venom gland transcriptomic, venomic and antivenomic analysis of the South African green tree snake (the boomslang), Dispholidus typus. Biochimica et Biophysica Acta (BBA) - General Subjects.

The page saysa 180-degree gape
The source saysBoomslangs have very long fangs and can open their mouths a full 180 degrees to bite.Note: adw-boomslang gives 170 degrees in a paragraph that also misclassifies the boomslang as Solenoglypha (fangs that fold); the peer-reviewed Pla et al. 2017 figure is used throughout
The page saysvenom that turns the blood against itself
The source saysDIC is caused by the consumption of fibrinogen (defibrination) into many small clots, resulting in blood that loses the ability to clot and thus the victim bleeds to death.Note: tagline paraphrase of the DIC mechanism
The page says180-degree gape that drives its rear fangs home
The source sayscan open their mouths a full 180 degrees to bite
The page saysspends almost all its time off the ground
The source saysalmost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake species
The page saysalong with chameleons and other tree lizards, frogs and the occasional egg
The source saysBoomslangs feed on chameleons and other arboreal lizards, frogs, and occasionally small mammals, birds, and eggs from nesting birds
The page saysThe boomslang is not a front-fanged snake: its fangs sit toward the back of its upper jaw
The source saysalmost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake speciesNote: opisthoglyphous means the enlarged fangs sit at the rear of the upper jaw; the same paper calls the boomslang a 'non-front-fanged colubroid' species
The page saysIt can open its mouth a full 180 degrees and work those long fangs into its target, a motion more like chewing than a strike
The source saysBoomslangs have very long fangs and can open their mouths a full 180 degrees to bite.Note: 'more like chewing' from adw-boomslang: 'When they bite, it appears as though they are chewing because of their rear-fangs.'
The page saysRoughly three-quarters of the toxins in boomslang venom are metalloproteinases
The source saysthe vast majority of toxin genes expressed in the venom gland transcriptome (~ 75%) and toxin proteins detected in secreted venom (~ 78%) are SVMPs
The page saysThe clotting factors get used up making many small, useless clots, and once they run out, the blood can't clot
The source saysDIC is caused by the consumption of fibrinogen (defibrination) into many small clots, resulting in blood that loses the ability to clot and thus the victim bleeds to death.
The page saysdisseminated intravascular coagulation, or DIC
The source saysdisseminated intravascular coagulation (DIC)-like syndrome
The page saysKarl Patterson Schmidt, an eminent American herpetologist
The source saysKarl Patterson Schmidt ... was an eminent American herpetologist at the Field Museum in Chicago
The page sayswas bitten on the thumb in 1957 by a juvenile boomslang sent to him for identification
The source saysSeptember 26, 1957 ... 24 h after being bitten on his thumb by a juvenile South African green tree snake ... The snake had been sent to him for identification
The page saysonly one fang went in, to its full length of about 3 mm
The source saysthe bite was made with the rear fangs only, only the right fang entering to its full length of about 3 mmNote: Schmidt's own account of that one bite, quoted in the paper; the snake was a juvenile
The page saysLike many herpetologists of his day, he wrongly believed a rear-fanged snake could not deliver a fatal dose to a human, so he kept meticulous notes on his own symptoms and refused medical care when it was offered
The source saysK. P. Schmidt, along with many of his contemporary herpetologists, wrongly believed that rear-fanged colubroid snakes could not produce a fatal venom dose for humans ... he made meticulous notes about the effects he experienced ... Schmidt was asked just a few hours before he died if he wanted medical care, but he refused
The page saysHe died of internal bleeding from his eyes, lungs, kidneys, heart and brain about 24 hours after the bite
The source saysHe died nearly 6 decades ago of internal bleeding from his eyes, lungs, kidneys, heart, and brain 24 h after being bitten on his thumb
The page saysone of the most dangerous snakes in Africa, probably causing more serious human bites than any other rear-fanged species
The source saysthe boomslang is considered one of the most deadly African snakes, and is probably responsible for more serious bites in humans than any other non-front-fanged colubroid species
The page saysBites generally happen only when someone tries to handle, catch or kill one
The source saysbites generally occur only when people attempt to handle, catch or kill the animal
The page saysRoughly three-quarters of the toxins in boomslang venom are metalloproteinases, enzymes that switch on the blood's clotting system.
The source saysthe vast majority of toxin genes expressed in the venom gland transcriptome (~ 75%) and toxin proteins detected in secreted venom (~ 78%) are SVMPsNote: FAQ 1, first sentence; 'switch on the blood's clotting system' from the same paper's 'procoagulant SVMPs' and 'depletion of fibrinogen from the blood as a result of prothrombin activation'
The page saysThe clotting factors get used up making many small, useless clots, and once they run out, the blood can't clot.
The source saysDIC is caused by the consumption of fibrinogen (defibrination) into many small clots, resulting in blood that loses the ability to clot and thus the victim bleeds to death.Note: FAQ 1, second sentence
The page saysDoctors call the result disseminated intravascular coagulation (DIC), and it's the mechanism that killed herpetologist Karl Patterson Schmidt about 24 hours after a bite on the thumb in 1957.
The source saysKarl Patterson Schmidt (June 19, 1890, Lake Forest, Illinois–September 26, 1957, Chicago) ... He died nearly 6 decades ago of internal bleeding from his eyes, lungs, kidneys, heart, and brain 24 h after being bitten on his thumb by a juvenile South African green tree snakeNote: FAQ 1, third sentence; the 1957 date is the death date in the same sentence, 24 h after the bite; DIC term from the paper's 'disseminated intravascular coagulation (DIC)-like syndrome'
The page saysThe boomslang is not a front-fanged snake: its fangs sit toward the back of its upper jaw.
The source saysalmost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake speciesNote: FAQ 2, first sentence; opisthoglyphous means the enlarged fangs sit at the rear of the upper jaw
The page saysTo use them, it can open its mouth a full 180 degrees and work those long fangs into its target.
The source saysBoomslangs have very long fangs and can open their mouths a full 180 degrees to bite.Note: FAQ 2, second sentence
The page saysit would rather flee than fight
The source saysThe boomslang is a mellow, shy snake that will flee from anything too large to eat, and will bite only when people attempt to handle, catch or kill the animal
The page saysswings its jaws open a full 180 degrees to bite
The source sayscan open their mouths a full 180 degrees to biteNote: vibe.reason

Source
05

Debono et al. 2017

Debono et al. (2017). Coagulating Colubrids: Evolutionary, Pathophysiological and Biodiscovery Implications of Venom Variations between Boomslang (Dispholidus typus) and Twig Snake (Thelotornis mossambicanus). Toxins.

The page sayshuge round-pupil eyes
The source saysvery large eyes with circular pupils and acute vision
The page saysBirds, chameleons and other tree lizards, plus frogs and occasional eggs
The source saysBirds account for the majority of Dispholidus prey items as it hunts in the canopy.Note: the sources disagree on rank: debono-2017 makes birds the majority of prey, while adw-boomslang and pla-2017 make arboreal lizards and frogs the main diet and birds occasional, so the stat line and the body list prey without ranking it
The page sayshunts the canopy
The source saysBirds account for the majority of Dispholidus prey items as it hunts in the canopy.
The page saysunusually large eyes, round pupils and sharp vision
The source saysvery large eyes with circular pupils and acute vision
The page saysagile, fast-moving snake that chases prey through the branches rather than waiting in ambush
The source saysAs D. typus is an agile and fast-moving snake, it is able to pursue prey, thus minimising escape potential.Note: the source draws the same contrast, against the ambush-feeding Thelotornis: 'T. mossambicanus however is a slower moving cryptic snake that ambush feeds'
The page saysIt hunts birds in the canopy
The source saysBirds account for the majority of Dispholidus prey items as it hunts in the canopy.
The page saysChameleons are slow and harmless, and it takes them by day, when their own circulation is running fastest
The source saysthey are non-dangerous and slow moving and are also taken during their diurnal activity period when blood circulation is at its maximum
The page sayswhose fast circulation leaves them quick to subdue
The source saysThe fast-moving, endothermic blood circulatory system of avians is similar to mammals in being vulnerable to rapid prey subjugation by stroke formationNote: of birds, the prey named in the same sentence
The page saysan agile snake that chases birds through the canopy rather than waiting in ambush
The source saysAs D. typus is an agile and fast-moving snake, it is able to pursue prey, thus minimising escape potential.Note: vibe.reason
The page sayschases birds through the canopy
The source saysBirds account for the majority of Dispholidus prey items as it hunts in the canopy.Note: vibe.reason

Source
06

Menzies et al. 2022

Menzies et al. (2022). In vitro and in vivo preclinical venom inhibition assays identify metalloproteinase inhibiting drugs as potential future treatments for snakebite envenoming by Dispholidus typus. Toxicon: X.

The page saysA metalloproteinase-loaded hemotoxin that triggers uncontrolled clotting
The source sayshighly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogenNote: 'triggers uncontrolled clotting until the clotting factors run out' paraphrases prothrombin activation plus clotting-factor consumption in this quote
The page saysuntil the blood's clotting factors run out
The source sayshighly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen
The page saysacross sub-Saharan Africa
The source saysD. typus exhibits a broad geographical distribution throughout much of sub-Saharan Africa
The page saysenzymes that switch on the blood's clotting system
The source sayshighly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogenNote: pla-2017 states the same for this venom: 'A central feature of the clinical pathology produced by envenomations by procoagulant SVMPs is a DIC-like ... syndrome'
The page saysThere's only one treatment: a monovalent antivenom made specifically for boomslang venom
The source saysThe only available treatment for D. typus envenoming is the monovalent SAIMR Boomslang antivenom.
The page saysIt's often hard to source, and at around $6,000 a vial, it's out of reach for many snakebite patients
The source saysthis antivenom is often difficult to source and, at US$6000/vial, typically unaffordable for most snakebite patients
The page saysresearchers are now testing whether cheaper drugs that block the same clotting enzymes could work as a backup
The source saysmarimastat and DMPS should be further explored as potentially valuable early intervention therapeutics to broadly treat VICC following snakebite envenoming in sub-Saharan Africa
The page sayscheaper drugs that block the same clotting enzymes
The source saysSmall molecule drugs have a number of potentially advantageous characteristics over antivenoms, including improved affordability and stability
The page saysThere's only one: a monovalent antivenom made specifically for Dispholidus typus venom.
The source saysThe only available treatment for D. typus envenoming is the monovalent SAIMR Boomslang antivenom.Note: FAQ 3, first sentence
The page saysIt's often hard to source, and at around $6,000 a vial, it's out of reach for many snakebite patients, which has pushed researchers to test whether cheaper drugs that block the same clotting enzymes could work as a backup treatment.
The source saysthis antivenom is often difficult to source and, at US$6000/vial, typically unaffordable for most snakebite patients ... marimastat and DMPS should be further explored as potentially valuable early intervention therapeuticsNote: FAQ 3, second sentence; 'cheaper' from the same paper's 'Small molecule drugs have a number of potentially advantageous characteristics over antivenoms, including improved affordability and stability'
The page saystags: venomous
The source sayshighly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogenNote: task #613; the profile carried no venomous tag

Source
07

Leisewitz et al. 2004

Leisewitz et al. (2004). The diagnosis and management of snakebite in dogs - a southern African perspective. Journal of the South African Veterinary Association.

The page saysDogs may be bitten more often than people
The source saysThe boomslang (Dispholidus typus) and the vine snake (coagulopathic venom) rarely bite humans but dogs may be bitten more frequently.
The page saysbecause they go after snakes mouth-first, snakebites on dogs usually land on the face or neck
The source saysThe most common bite site in dogs is cranial to the shoulders, especially the face and the loose skin around the neck as dogs attack snakes with their mouths.Note: the bite-site figure is for snakebite in dogs in southern Africa generally, not boomslang bites alone, which is how the sentence is worded

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.