Identification
This is relevant for all animals belonging to Terrestrial Snakes in Mexico and Central America.
Snake not available
Distribution
See Geographical Distribution to narrow down the possible culprits on country/state level.
Biological Features
Mexico and Central America
Description of the most important representatives:
| General behaviour | Habitats | Appearance | Defensive behaviour | Factors relevant to envenoming | |
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Micrurus sp. and
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primarily nocturnal ground-dwelling |
primarily in mesic and dry forests, up to altitudes of over 2,000 m, some species also in stony or sandy arid areas; sometimes close to human settlements and in coffee plantations |
conspicuous warning colouring consisting of black, red and yellow cross bands (a number of harmless colubrids also have this colouring) |
when threatened, the end of the tail is raised in the air and moved back and forth; the head is sometimes hidden under the coils of the body |
generally non-aggressive behaviour; accidents uncommon |
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nocturnal in warm weather, diurnal in cool ground-dwelling |
dry forests, A. bilineatus also in savanna-like regions |
sturdy body, rarely over 1 m; A. bilineatus has 2 white lines along each side of the head |
accidents due to A. bilineatus appear to be relatively rare |
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primarily nocturnal ground-dwelling |
in forested areas and plantations; often along rivers |
sturdy body, length up to around 2 m or more |
generally irritable; they dart forwards from a tensed position and often strike repeatedly |
common cause of serious snakebites |
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primarily nocturnal ground-dwelling |
open arid areas, from the lowlands to mountains; sometimes also in savanna-like grasslands, as well as sparse forest |
stout body with characteristic rattle on the end of the tail; smaller species around 60 cm, the largest up to 1.5 m |
a typical dry and high warning sound is produced by vibration of the rattle; during this process the body is coiled into a tight S-shape |
in Mexico, where many species are found, the most common cause of severe snakebite envenoming |
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nocturnal ground-dwelling |
primary rainforest, remote from civilisation |
stout body, length up to 3.5 m! |
relatively unaggressive during the day, marked defensive behaviour at night, neck is inflated and the tip of the tail is vibrated, then easily provoked into striking |
as Lachesis hardly ever comes into contact with humans, accidents are relatively rare |
Snake available
Morphological Identification
Morphological key to the terrestrial venomous snakes
| Only ever pick up dead snakes! Caution - reflex bites are possible in snakes that have only just been killed. Hold the snake with one hand behind the head, and with the other hand open the mouth using tweezers and observe the dentition (also look for teeth that may be hidden in mucosal folds). | ||||
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Are all the teeth +/- of the same size? | yes |
Harmless snakes (local symptoms may occur) |
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| no
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Enlarged teeth (venom fangs, generally grooved at the front or with a venom duct orifice near the tip) are +/- at the back; there are always normal teeth in front of these venom fangs! | yes |
some species of Colubridae |
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| no
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Venom fangs are at the very front of the row of teeth and are +/- fixed (not moveable) in the upper jaw. May be so small as to be barely visible! | yes
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Elapidae (no Elapidae in Europe!) » proceed to regional identification |
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| no
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| Exceedingly long venom fangs at the very front of the upper jaw that can be erected forwards, in rare cases laterally. Normally they are folded back and covered by mucosal sheaths! | ||||
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Is there a pit between the nostril and the eye? | yes
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Crotalinae (no Crotalinae in Central and Southern Africa, and Australia!) » proceed to regional identification |
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| no | ||||
| Viperinae (no Viperinae in the Americas and Australia!) | ||||