---
title: "What the sources say about the Boomslang | AnimalTracks.wiki"
description: "60 claims from the Boomslang profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/boomslang-1.webp"
canonical: "https://animaltracks.wiki/animals/boomslang/sources/"
---

# What the sources say about the Boomslang (*Dispholidus typus*)

> 60 claims from the Boomslang profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Boomslang](https://animaltracks.wiki/animals/boomslang/)

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

https://doi.org/10.2305/iucn.uk.2021-2.rlts.t190603a15357215.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN 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) |

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

https://animaldiversity.org/accounts/Dispholidus_typus/

| The page says | The source says |
| :--- | :--- |
| Karoo scrub, arid savanna, and east African lowland forest | commonly found in karoo scrubs, arid savannas, and east African lowland forests |
| chameleons and other tree lizards, plus frogs and occasional eggs | main diet consists of small arboreal lizards and frogs, including chameleons. Occasionally, they feed on small mammals, birds, the eggs of reptiles and birds |
| It's most common in Eswatini, Botswana, Namibia, Mozambique and Zimbabwe | most abundant in Swaziland, Botswana, Namibia, Mozambique, and Zimbabwe (note: the source names Swaziland, the country's name until it was renamed Eswatini in 2018; same territory) |
| recorded as far north as Nigeria and southern Chad | have been observed as far north as Nigeria and southern Chad |
| favors karoo scrub, arid savanna and east African lowland forest, keeping mostly to low trees and shrubs | commonly found in karoo scrubs, arid savannas, and east African lowland forests (note: 'mostly to low trees and shrubs' from adw-boomslang: 'They mainly live in low-lying shrubs and short trees.') |
| runs 1.2 to 1.5 meters long, occasionally reaching 2 meters | Average length of an adult is 1.2 to 1.5 meters ... Range length 1.2 to 2.0 m |
| Most snakes have poor eyesight | Snakes, in general, do not have well developed eyesight but are able to see movement and color. |
| Symptoms can take several hours to appear | This slow-acting venom causes symptoms to start occurring in the victim several hours after contact |
| tags: savanna | commonly found in karoo scrubs, arid savannas, and east African lowland forests (note: task #613) |
| tags: arid | Karoo 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) |
| tags: forest | commonly found in karoo scrubs, arid savannas, and east African lowland forests (note: task #613; replaces woodland, whose definition is temperate deciduous and mixed forest. East African lowland forest is tropical) |

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

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

| The page says | The source says |
| :--- | :--- |
| The record lifespan is 8.7 years, set in captivity | Maximum longevity 8.7 years (captivity) |

## 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.

https://doi.org/10.1016/j.bbagen.2017.01.020

| The page says | The source says |
| :--- | :--- |
| a 180-degree gape | Boomslangs 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) |
| venom that turns the blood against itself | DIC 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) |
| 180-degree gape that drives its rear fangs home | can open their mouths a full 180 degrees to bite |
| spends almost all its time off the ground | almost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake species |
| along with chameleons and other tree lizards, frogs and the occasional egg | Boomslangs feed on chameleons and other arboreal lizards, frogs, and occasionally small mammals, birds, and eggs from nesting birds |
| The boomslang is not a front-fanged snake: its fangs sit toward the back of its upper jaw | almost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake species (note: 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) |
| It can open its mouth a full 180 degrees and work those long fangs into its target, a motion more like chewing than a strike | Boomslangs 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.') |
| Roughly three-quarters of the toxins in boomslang venom are metalloproteinases | the vast majority of toxin genes expressed in the venom gland transcriptome (~ 75%) and toxin proteins detected in secreted venom (~ 78%) are SVMPs |
| The clotting factors get used up making many small, useless clots, and once they run out, the blood can't clot | DIC 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. |
| disseminated intravascular coagulation, or DIC | disseminated intravascular coagulation (DIC)-like syndrome |
| Karl Patterson Schmidt, an eminent American herpetologist | Karl Patterson Schmidt ... was an eminent American herpetologist at the Field Museum in Chicago |
| was bitten on the thumb in 1957 by a juvenile boomslang sent to him for identification | September 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 |
| only one fang went in, to its full length of about 3 mm | the bite was made with the rear fangs only, only the right fang entering to its full length of about 3 mm (note: Schmidt's own account of that one bite, quoted in the paper; the snake was a juvenile) |
| Like 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 | K. 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 |
| He died of internal bleeding from his eyes, lungs, kidneys, heart and brain about 24 hours after the bite | 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 |
| one of the most dangerous snakes in Africa, probably causing more serious human bites than any other rear-fanged species | the 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 |
| Bites generally happen only when someone tries to handle, catch or kill one | bites generally occur only when people attempt to handle, catch or kill the animal |
| Roughly three-quarters of the toxins in boomslang venom are metalloproteinases, enzymes that switch on the blood's clotting system. | the vast majority of toxin genes expressed in the venom gland transcriptome (~ 75%) and toxin proteins detected in secreted venom (~ 78%) are SVMPs (note: 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 clotting factors get used up making many small, useless clots, and once they run out, the blood can't clot. | DIC 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) |
| Doctors 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. | Karl 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 snake (note: 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 boomslang is not a front-fanged snake: its fangs sit toward the back of its upper jaw. | almost exclusively arboreal opisthoglyphous (rear-fanged) colubroid snake species (note: FAQ 2, first sentence; opisthoglyphous means the enlarged fangs sit at the rear of the upper jaw) |
| To use them, it can open its mouth a full 180 degrees and work those long fangs into its target. | Boomslangs have very long fangs and can open their mouths a full 180 degrees to bite. (note: FAQ 2, second sentence) |
| it would rather flee than fight | The 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 |
| swings its jaws open a full 180 degrees to bite | can open their mouths a full 180 degrees to bite (note: vibe.reason) |

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

https://doi.org/10.3390/toxins9050171

| The page says | The source says |
| :--- | :--- |
| huge round-pupil eyes | very large eyes with circular pupils and acute vision |
| Birds, chameleons and other tree lizards, plus frogs and occasional eggs | Birds 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) |
| hunts the canopy | Birds account for the majority of Dispholidus prey items as it hunts in the canopy. |
| unusually large eyes, round pupils and sharp vision | very large eyes with circular pupils and acute vision |
| agile, fast-moving snake that chases prey through the branches rather than waiting in ambush | As 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') |
| It hunts birds in the canopy | Birds account for the majority of Dispholidus prey items as it hunts in the canopy. |
| Chameleons are slow and harmless, and it takes them by day, when their own circulation is running fastest | they are non-dangerous and slow moving and are also taken during their diurnal activity period when blood circulation is at its maximum |
| whose fast circulation leaves them quick to subdue | The fast-moving, endothermic blood circulatory system of avians is similar to mammals in being vulnerable to rapid prey subjugation by stroke formation (note: of birds, the prey named in the same sentence) |
| an agile snake that chases birds through the canopy rather than waiting in ambush | As D. typus is an agile and fast-moving snake, it is able to pursue prey, thus minimising escape potential. (note: vibe.reason) |
| chases birds through the canopy | Birds account for the majority of Dispholidus prey items as it hunts in the canopy. (note: vibe.reason) |

## 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.

https://doi.org/10.1016/j.toxcx.2022.100118

| The page says | The source says |
| :--- | :--- |
| A metalloproteinase-loaded hemotoxin that triggers uncontrolled clotting | highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen (note: 'triggers uncontrolled clotting until the clotting factors run out' paraphrases prothrombin activation plus clotting-factor consumption in this quote) |
| until the blood's clotting factors run out | highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen |
| across sub-Saharan Africa | D. typus exhibits a broad geographical distribution throughout much of sub-Saharan Africa |
| enzymes that switch on the blood's clotting system | highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen (note: 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') |
| There's only one treatment: a monovalent antivenom made specifically for boomslang venom | The only available treatment for D. typus envenoming is the monovalent SAIMR Boomslang antivenom. |
| It's often hard to source, and at around $6,000 a vial, it's out of reach for many snakebite patients | this antivenom is often difficult to source and, at US$6000/vial, typically unaffordable for most snakebite patients |
| researchers are now testing whether cheaper drugs that block the same clotting enzymes could work as a backup | marimastat and DMPS should be further explored as potentially valuable early intervention therapeutics to broadly treat VICC following snakebite envenoming in sub-Saharan Africa |
| cheaper drugs that block the same clotting enzymes | Small molecule drugs have a number of potentially advantageous characteristics over antivenoms, including improved affordability and stability |
| There's only one: a monovalent antivenom made specifically for Dispholidus typus venom. | The only available treatment for D. typus envenoming is the monovalent SAIMR Boomslang antivenom. (note: FAQ 3, first sentence) |
| It'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. | this 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 therapeutics (note: 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') |
| tags: venomous | highly abundant prothrombin-activating snake venom metalloproteinases (SVMPs) consume clotting factors and deplete fibrinogen (note: task #613; the profile carried no venomous tag) |

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

https://doi.org/10.4102/jsava.v75i1.441

| The page says | The source says |
| :--- | :--- |
| Dogs may be bitten more often than people | The boomslang (Dispholidus typus) and the vine snake (coagulopathic venom) rarely bite humans but dogs may be bitten more frequently. |
| because they go after snakes mouth-first, snakebites on dogs usually land on the face or neck | The 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) |