---
title: "What the sources say about the South American Bushmaster | AnimalTracks.wiki"
description: "48 claims from the South American Bushmaster profile, each beside the words of the source that backs it."
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---

# What the sources say about the South American Bushmaster (*Lachesis muta*)

> 48 claims from the South American Bushmaster profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [South American Bushmaster](https://animaltracks.wiki/animals/south-american-bushmaster/)

## Lachesis muta (South American bushmaster). Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Lachesis_muta/

| The page says | The source says |
| :--- | :--- |
| Its scientific name means "silent fate," | The scientific name Lachesis muta means "silent fate" referring to their tail shaking, though they lack a rattle. |
| a nod to the tail it shakes when threatened, though it has no rattle | Like other vipers, they rattle their tails when threatened, but there are no actual rattles. |
| Hatchlings emerge at approximately 30 to 50 centimeters long with a bright orange or yellow tail tip used to lure prey, a color that fades as they grow older. | The young hatch at approximately 30 to 50 cm with bright orange or yellow tail tips, used to lure prey; this color fades over time. |
| Nobody knows how long one lives in the wild | Lifespan of wild individuals is unknown. |
| where it is so secretive that many of its habits are unknown | Many of their habits are unknown as they are so secretive. |
| The Central American bushmasters were described as subspecies of Lachesis muta, and many now treat them as full species | At least three subspecies have been described are now considered full species by many authors (note: ADW 2012, after the 1994-2003 splits it cites; no quote names L. acrochorda, so it is left out) |
| the Central American bushmaster, from southeastern Nicaragua to the Pacific coast of Colombia and Ecuador, and the black-headed bushmaster of southeastern Costa Rica | Lachesis muta stenophrys, the Central American bushmaster, occurs from southeastern Nicaragua to the Pacific coast of Columbia and Ecuador. Lachesis muta melanocephala, black-headed bushmaster, occurs in southeastern Costa Rica |
| Lachesis muta keeps the rest of the range in South America. | Lachesis muta muta encompasses the remainder of the range in South America. |
| dangerLevel: Deadly | Their venom attacks the circulatory system and can cause death without treatment. |

## Lachesis muta (Bushmaster or Mapepire Zanana). The Online Guide to the Animals of Trinidad and Tobago, University of the West Indies.

https://sta.uwi.edu/fst/lifesciences/sites/default/files/lifesciences/documents/ogatt/Lachesis_muta%20-%20Bushmaster%20or%20Mapepire%20Zanana.pdf

| The page says | The source says |
| :--- | :--- |
| The longest of all vipers | This terrestrial snake is the longest of all viperids. (note: UWI (Trinidad guide, c. 2011, after the splits) says this of Lachesis muta itself; the 1997 Toxicon 'world's longest pit viper' and ADW 2012 'second longest venomous snake' lines were broad-sense bushmaster and were cut) |
| able to aim a strike in the dark by body heat alone | If an endothermic (warm-blooded) animal is closer than 50 cm in any direction from the bushmaster, it can detect its heat signature and aim its strike precisely without any other sensory information. (note: 'in the dark': 'Bushmasters hunt at night and are ambush predators') |
| from the only pit vipers in the Americas that lay eggs | Bushmaster females are oviparous (egg-laying) and are the only oviparous pit vipers in the Western Hemisphere. (note: source's own plural: all bushmasters (the genus) lay eggs, so the rank is not pinned on L. muta alone) |
| Small rainforest mammals, especially the rice rat Oryzomys, and sometimes birds | The small rice rat, Oryzomys sp., is the bushmaster's favourite in the wild. ... commonly small mammals and sometimes birds up to 120 g |
| Facial heat-sensing pits that let it aim a strike at a warm body within 50 centimeters with no other senses needed | If an endothermic (warm-blooded) animal is closer than 50 cm in any direction from the bushmaster, it can detect its heat signature and aim its strike precisely without any other sensory information. |
| backed by venom produced in quantities of up to 400 milligrams | is produced in such large quantities (up to 400 mg) that the prey is dead within minutes |
| By day the South American bushmaster (*Lachesis muta*) rests in a burrow | They spend most of the daylight period in their burrows resting until the sun goes down. |
| it did not dig, stolen from or shared with an agouti or an armadillo | The bushmaster does not make its own home but scouts its environment for burrows made by large rodents such as agouti or armadillos and either steals the burrow for itself or shares it with the other animal. |
| it moves infrequently and very slowly | Bushmasters are very cryptic, move infrequently and very slowly |
| Adults are usually well over 2.5 meters long and weigh 3 to 5 kilograms | Adults are usually well over 250 cm and 3-5 kg (note: 250 cm converted to 2.5 m) |
| some of the longest reach about 3.5 meters | with some of the longest approximately 350 cm (note: 350 cm converted to 3.5 m) |
| making it the longest of all vipers | This terrestrial snake is the longest of all viperids. |
| A bushmaster hunts at night by ambush | Bushmasters hunt at night and are ambush predators. |
| hidden under leaves or dense foliage until prey comes within range | They are ambush predators and so lie in the dark waiting, hidden under leaves or in dense foliage until prospective prey comes within strike range. |
| A pair of pits between its eyes and nostrils reads infrared heat | bushmasters have one heat-sensing pit, on each side of their head midway between the nostril and eye |
| if a warm body comes within 50 centimeters, the snake can aim its strike from that heat signature alone, with no other senses involved | If an endothermic (warm-blooded) animal is closer than 50 cm in any direction from the bushmaster, it can detect its heat signature and aim its strike precisely without any other sensory information. |
| Its favorite meal in the wild is the small rice rat. | The small rice rat, Oryzomys sp., is the bushmaster's favourite in the wild. |
| Prey over 120 grams is usually struck, released and trailed by scent. | They usually strike-release then perform chemosensory searching and trail-following if they prey weighs over 120 g (note: 'trailed by scent' for 'chemosensory searching and trail-following') |
| Its venom is relatively weak next to its close relatives', but it comes in volume | Its venom, though relatively weak to closely related species, is produced in such large quantities |
| up to 400 milligrams, one of the largest amounts produced by any snake | is produced in such large quantities (up to 400 mg) that the prey is dead within minutes. This is one of the largest volumes of venom produced by any species of snake. |
| enough that even released prey usually dies within minutes | Even if the prey gets away because of its size, the venom will usually kill it within minutes. |
| The Egg-Laying Exception | Bushmaster females are oviparous (egg-laying) and are the only oviparous pit vipers in the Western Hemisphere. |
| Bushmasters are the only pit vipers in the Western Hemisphere that lay eggs. | Bushmaster females are oviparous (egg-laying) and are the only oviparous pit vipers in the Western Hemisphere. |
| A female lays 8 to 12 white eggs, each a little larger than a chicken egg, coils her body around the clutch, and does not leave it for any reason until the eggs hatch roughly 78 days later. | She lays eight to twelve white eggs, a little larger than a chicken egg. After laying, she wraps her body around them and protects them until approximately 78 days later when they hatch ... She does not leave her eggs for any reason during this period. (note: eight to twelve spelled out as 8 to 12) |
| A bushmaster lies hidden under leaves until prey comes within strike range | They are ambush predators and so lie in the dark waiting, hidden under leaves or in dense foliage until prospective prey comes within strike range. |
| a warm body closer than 50 centimeters is enough to aim by heat alone | If an endothermic (warm-blooded) animal is closer than 50 cm in any direction from the bushmaster, it can detect its heat signature and aim its strike precisely without any other sensory information. |
| weightKg: 4 | Adults are usually well over 250 cm and 3-5 kg (note: 4 kg is the midpoint of the 3 to 5 kg adult range; every value in it is the Light class) |

## AnAge entry for Lachesis muta. AnAge: The Animal Ageing and Longevity Database.

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

| The page says | The source says |
| :--- | :--- |
| The longest-lived on record reached 31.6 years in captivity. | Maximum longevity 31.6 years (captivity) (note: AnAge Build 15 (2023) supersedes ADW's 2012 captive record of 24 years; 'longest-lived on record' restates 'Maximum longevity') |
| The longest-lived on record reached 31.6 years in captivity. | Maximum longevity 31.6 years (captivity) (note: FAQ copy of the body's lifespan claim; FAQ ref is AnAge, which states the figure; 'longest-lived on record' restates 'Maximum longevity') |

## Gutiérrez-Cárdenas et al. (2021). Lachesis muta. The IUCN Red List of Threatened Species 2021: e.T62254A44946798.

https://doi.org/10.2305/iucn.uk.2021-3.rlts.t62254a44946798.en

| The page says | The source says |
| :--- | :--- |
| Least Concern | IUCN Red List category: Least Concern (LC). (note: read through GBIF's copy of the Red List, since iucnredlist.org refuses scripts (docs/fact-check.md); assessment DOI dated 2021, after ADW 2012's 'Vulnerable') |
| the IUCN lists the species as Least Concern | IUCN Red List category: Least Concern (LC). (note: read through GBIF's copy of the Red List; assessment DOI dated 2021) |

## Pinho & Pereira (2001). Ofidismo. Revista da Associação Médica Brasileira.

https://doi.org/10.1590/s0104-42302001000100026

| The page says | The source says |
| :--- | :--- |
| Rainforest across the Amazon and Atlantic Forest, with pockets of humid forest in northeastern Brazil | Habitam áreas florestais como Amazônia, Mata Atlântica e alguns enclaves de matas úmidas do Nordeste (note: translated from Portuguese: 'They inhabit forest areas like the Amazon, the Atlantic Forest and some humid forest enclaves of the Northeast') |
| A 2001 Brazilian medical review notes that most of the country's snakebites come from lanceheads and rattlesnakes, and that bites by Lachesis are rare. | A maioria destes acidentes deve-se a serpentes do gênero Bothrops (jararaca, jararacuçu, urutu e outros) e Crotalus (cascavel), sendo raros os produzidos por Lachesis (note: translated from Portuguese: 'Most of these accidents are due to snakes of the genus Bothrops (jararaca, jararacuçu, urutu and others) and Crotalus (rattlesnake), those produced by Lachesis being rare'; 'lanceheads' is the standard English name for Bothrops; 2001 is the review's publication year (reference year); 'most' translates 'A maioria') |
| Their systemic effects can include low blood pressure, dizziness, darkened vision, a slowed heartbeat, abdominal cramps and diarrhea, grouped as a "vagal syndrome." | As manifestações sistêmicas incluem hipotensão arterial, tonturas, escurecimento da visão, bradicardia, cólicas abdominais e diarréia ("síndrome vagal") (note: translated from Portuguese: 'Systemic manifestations include low blood pressure, dizziness, darkening of vision, bradycardia, abdominal cramps and diarrhea ("vagal syndrome")'; scoped to the Brazilian review) |
| The bushmaster lives in forest across the Amazon and the Atlantic Forest, with pockets of humid forest in Brazil's northeast | Habitam áreas florestais como Amazônia, Mata Atlântica e alguns enclaves de matas úmidas do Nordeste (note: translated from Portuguese, same passage as the stats.habitat claim) |
| In the national figures for 1990 to 1993, Lachesis caused 1.4 percent of the snakebites whose snake genus was recorded, against 90.5 percent for Bothrops lanceheads and 7.7 percent for rattlesnakes. | no período de 1990 a 1993 ocorreram 81.611 acidentes ... Dentre os casos em que o gênero da serpente foi informado, Bothrops foi responsável por 90,5% dos casos, Crotalus por 7,7%, Lachesis por 1,4% (note: translated from Portuguese: 'in the period 1990 to 1993 there were 81,611 accidents ... Among the cases where the snake's genus was reported, Bothrops was responsible for 90.5% of cases, Crotalus 7.7%, Lachesis 1.4%'; decimal commas converted) |

## Junqueira-de-Azevedo et al. (2006). Lachesis muta (Viperidae) cDNAs Reveal Diverging Pit Viper Molecules and Scaffolds Typical of Cobra (Elapidae) Venoms: Implications for Snake Toxin Repertoire Evolution. Genetics.

https://doi.org/10.1534/genetics.106.056515

| The page says | The source says |
| :--- | :--- |
| A Viper's Venom with Cobra Parts | an ohanin-like toxin, which would be the third member of the most recently described class of Elapidae toxins (note: the paper's title calls these 'Scaffolds Typical of Cobra (Elapidae) Venoms') |
| Geneticists sequencing bushmaster venom genes found atypical molecules "never observed in the hundreds of Viperidae snakes studied so far," | atypical molecules never observed in the hundreds of Viperidae snakes studied so far are highly expressed (note: 'venom genes' for the paper's cDNAs of possible toxins) |
| including one from a class of toxins described from Elapidae, the snake family that includes cobras and mambas | an ohanin-like toxin, which would be the third member of the most recently described class of Elapidae toxins (note: 'the snake family that includes cobras and mambas' identifies Elapidae for readers; standard taxonomy) |