Hognose
Encyclopedia
The hognose snake is a type of colubrid
snake
characterized by an upturned snout. They are notorious for playing dead when threatened. The hognose snakes consist of three distantly related genera
that are artificially grouped together by the "hognose" common name: Heterodon
which are predominantly found in United States
and northern Mexico
. Leioheterodon
the Madagascar
hognose snakes, and Lystrophis
the South American or tri-colored hognose snakes.
:
Genus Leioheterodon
:
Genus Lystrophis
:
Hognose snakes are extremely variable in color and pattern. H. nasicus and H. kennerlyi tend to be sandy colored with black and white markings, while H. platirhinos varies from red
s, green
s, orange
s, brown
s, to melanistic (i.e. black
) depending on locality. They are sometimes blotched and sometimes solid-colored. L. geayi is a brown or tan
colored snake with dark speckling on it. L. madagascariensis is typically green and yellow
with a black checkerboard pattern along its back. L. modestus is normally a gold-brown color. The species in the genus Lystrophis are referred to as tri-color hognose snakes and sometimes as false coral snake
s because they display alternating bands of red, white
, and black.
Leioheterodon are the largest of the hognose snakes, capable of reaching lengths of 1.8 m. H. platirhynos gets slightly larger than other species of the genus, reaching lengths of 80 cm, where other species in the genus as well as Lystrophis species usually average around 65 cm at adult size.
Hognose snakes (Heterodon) are rear-fanged and technically not venomous, but the saliva they excrete is considered toxic to prey but not considered to be dangerous to humans and they will never bite in defense (as the only way to get bitten by a hognose snake is to smell like their prey). There has been some debate whether or not hognose are venomous, but there is evidence that their saliva has some toxicity to smaller prey items, such as toads and frogs. The fangs have been referred to as just "enlarged teeth", but they are genuine fangs that are used for prey restraint. Despite the common belief, there is no evidence to support the fangs being used for "toad popping". Under this belief, the toads inflate their lungs to make swallowing difficult, but the fangs would penetrate the lungs and deflate them. However, whole toads with intact lungs are commonly regurgitated by recently captured hognoses.
The coloration of this essentially spotted snake is extremely variable,with color phases ranging from yellow and brown to black and gray. The most reliable field work is the turned-up, hoglike snout, which is used for digging out the toads that are its primary food.
, and hiss. They may sometimes feign strikes, but are not apt to bite. This behaviour has earned them several nicknames, such as "puff adder", "blowing adder", "flathead", "spreadhead", "spreading adder" or "hissing adder". Note, though, the nickname "puff adder" is only a nickname, and is not scientifically correct. There is a highly venomous viper
from Africa
called the puff adder, Bitis arietans
.
If this threat display does not work to deter a would-be predator
, hognose snakes will often roll onto their back and play dead, going so far as to emit a foul musk
and fecal matter
from their cloaca
and let their tongue
hang out of their mouth
, sometimes accompanied by small droplets of blood. If they are rolled upright while in this state, they will often roll back as if insisting they really are dead. It has been observed that the snake, while appearing to be dead, will still watch the animal that caused the death pose. The snake will 'resurrect' sooner if the threat is looking away from it than if the threat is looking at the snake.
Video of Display
are diurnal active foragers that typically consume their prey live without any constriction or body pinning.
For most hog nose snakes the bulk of their diet
is made up by rodent
s, and lizard
s. H. platirhinos is an exception, and specializes in feeding on toad
s although other food items such as eggs, insects and mice can make up as much as 50% of their diet.
trade. H. nasicus are often considered to be the easiest to care for, and captive bred stock is easily found. H. platirhinos is also commonly found, but their dietary requirements can be a challenge for some keepers, and there is anecdotal evidence to suggest that feeding them a diet of exclusively rodents contributes to liver problems and a shortened life span. Leioheterodon species are imported regularly from Madagascar, and are not often bred in captivity and get much larger, so can pose a set of different challenges for care. Lystrophis species are fairly new to the commercial reptile
trade, and are now commonly bred in captivity, but can be some of the more expensive hognose snakes available.
Colubrid
A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...
snake
Snake
Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...
characterized by an upturned snout. They are notorious for playing dead when threatened. The hognose snakes consist of three distantly related genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
that are artificially grouped together by the "hognose" common name: Heterodon
Heterodon
Heterodon is a genus of harmless colubrids found in North America. They are stout with upturned snouts and are perhaps best known for their characteristic threat displays. Three species are currently recognized.-Description:...
which are predominantly found in United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and northern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. Leioheterodon
Leioheterodon
Leioheterodon is a genus of harmless colubrids found only on the island of Madagascar. Three species are currently recognized.- Species :* Speckled Hognose Snake, Leioheterodon geayi...
the Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
hognose snakes, and Lystrophis
Lystrophis
Lystrophis is the genus of tri-colored South American hognose snakes.They mimic milk snakes or coral snakes with their red, black, and white ringed patterns.- Species :The genus Lystrophis has 4 recognized species:...
the South American or tri-colored hognose snakes.
Species
Genus HeterodonHeterodon
Heterodon is a genus of harmless colubrids found in North America. They are stout with upturned snouts and are perhaps best known for their characteristic threat displays. Three species are currently recognized.-Description:...
:
- Mexican Hognose Snake, Heterodon kennerlyi (KennicottRobert KennicottRobert Kennicott was an American naturalist.-Biography:Kennicott was born in New Orleans and grew up in "West Northfield" , Illinois, a town in the prairie north of the then nascent city of Chicago....
, 1860) - Heterodon nasicusHeterodon nasicusHeterodon nasicus is a harmless colubrid species found in North America and northern Mexico. Three subspecies are currently recognized, including the typical form described here.-Description:...
- Dusty Hognose Snake, Heterodon nasicus gloydi (Edgren, 1952)
- Western or Plains Hognose Snake, Heterodon nasicus nasicus (BairdSpencer Fullerton BairdSpencer Fullerton Baird was an American ornithologist, ichthyologist and herpetologist. Starting in 1850 he was assistant-secretary and later secretary of the Smithsonian Institution in Washington, D.C...
& GirardCharles Frédéric GirardCharles Frédéric Girard was a French biologist specializing in ichthyology and herpetology.Born in Mulhouse, France, he studied at the College of Neuchâtel, Switzerland as a student of Louis Agassiz. In 1847, he accompanied Agassiz as his assistant to Harvard...
, 1852) - Eastern Hognose Snake, Heterodon platirhinos (LatreillePierre André LatreillePierre André Latreille was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare species he found in the prison, Necrobia ruficollis...
, 1801) - Southern Hognose Snake, Heterodon simusHeterodon simusHeterodon simus is a harmless snake species found in the southeastern United States. No subspecies are currently recognized.-Description:Adults are 35.5-61 cm in length. Stout with a wide neck and a sharply upturned snout...
(LinnaeusCarolus LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1766)
Leioheterodon
Leioheterodon is a genus of harmless colubrids found only on the island of Madagascar. Three species are currently recognized.- Species :* Speckled Hognose Snake, Leioheterodon geayi...
:
- Speckled Hognose Snake, Leioheterodon geayi (Mocquard, 1905)
- Malagasy Giant Hognose Snake, Leioheterodon madagascariensis (DumérilAndré Marie Constant DumérilAndré Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...
& BibronGabriel BibronGabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...
, 1854) - Blonde Hognose Snake, Leioheterodon modestus (GüntherAlbert C. L. G. GüntherAlbert Karl Ludwig Gotthilf Günther FRS, also Albert Charles Lewis Gotthilf Günther , was a German-born British zoologist, ichthyologist, and herpetologist....
, 1863)
Genus Lystrophis
Lystrophis
Lystrophis is the genus of tri-colored South American hognose snakes.They mimic milk snakes or coral snakes with their red, black, and white ringed patterns.- Species :The genus Lystrophis has 4 recognized species:...
:
- South American Hognose Snake, Lystrophis dorbignyi (DumérilAndré Marie Constant DumérilAndré Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...
, BibronGabriel BibronGabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...
& DumérilAuguste DumérilAuguste Henri André Duméril was a French zoologist. He was professor of Herpetology and Ichthyology at the Muséum National d'Histoire Naturelle in Paris from 1857. His father André Marie Constant Duméril was also a zoologist...
, 1854) - Jan's Hognose Snake, Lystrophis histricus (Jan, 1863)
- Lystrophis matogrossensis (Scrocchi & Cruz, 1993)
- Tri-color Hognose Snake, Lystrophis pulcher (Jan, 1863)
- Ringed Hognose Snake, Lystrophis semicinctus (DumérilAndré Marie Constant DumérilAndré Marie Constant Duméril was a French zoologist. He was professor of anatomy at the Muséum National d'Histoire Naturelle from 1801 to 1812, when he became professor of herpetology and ichthyology...
, BibronGabriel BibronGabriel Bibron was a French zoologist. He was born in Paris. Son of an employee of the Museum national d'histoire naturelle, he had a good foundation in natural history and was hired to collect vertebrates in Italy and Sicily. He classified a number of reptile species with André Marie Constant...
& DumérilAuguste DumérilAuguste Henri André Duméril was a French zoologist. He was professor of Herpetology and Ichthyology at the Muséum National d'Histoire Naturelle in Paris from 1857. His father André Marie Constant Duméril was also a zoologist...
, 1854)
Description
Hognose snakes' most distinguishing characteristic is their upturned snout, which aids in digging in sandy soils by using a sweeping, side to side motion. They also like to burrow in masses of humus.Hognose snakes are extremely variable in color and pattern. H. nasicus and H. kennerlyi tend to be sandy colored with black and white markings, while H. platirhinos varies from red
Red
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
s, green
Green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
s, orange
Orange (colour)
The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The...
s, brown
Brown
Brown is a color term, denoting a range of composite colors produced by a mixture of orange, red, rose, or yellow with black or gray. The term is from Old English brún, in origin for any dusky or dark shade of color....
s, to melanistic (i.e. black
Black
Black is the color of objects that do not emit or reflect light in any part of the visible spectrum; they absorb all such frequencies of light...
) depending on locality. They are sometimes blotched and sometimes solid-colored. L. geayi is a brown or tan
Tan (color)
Tan is a pale whiteish, tawny shade of white. The name is derived from tannum used in the tanning of leather.The first recorded use of tan as a shade name in English was in the year 1590....
colored snake with dark speckling on it. L. madagascariensis is typically green and yellow
Yellow
Yellow is the color evoked by light that stimulates both the L and M cone cells of the retina about equally, with no significant stimulation of the S cone cells. Light with a wavelength of 570–590 nm is yellow, as is light with a suitable mixture of red and green...
with a black checkerboard pattern along its back. L. modestus is normally a gold-brown color. The species in the genus Lystrophis are referred to as tri-color hognose snakes and sometimes as false coral snake
Coral snake
The coral snakes are a large group of elapid snakes that can be subdivided into two distinct groups, Old World coral snakes and New World coral snakes...
s because they display alternating bands of red, white
White
White is a color, the perception of which is evoked by light that stimulates all three types of color sensitive cone cells in the human eye in nearly equal amounts and with high brightness compared to the surroundings. A white visual stimulation will be void of hue and grayness.White light can be...
, and black.
Leioheterodon are the largest of the hognose snakes, capable of reaching lengths of 1.8 m. H. platirhynos gets slightly larger than other species of the genus, reaching lengths of 80 cm, where other species in the genus as well as Lystrophis species usually average around 65 cm at adult size.
Hognose snakes (Heterodon) are rear-fanged and technically not venomous, but the saliva they excrete is considered toxic to prey but not considered to be dangerous to humans and they will never bite in defense (as the only way to get bitten by a hognose snake is to smell like their prey). There has been some debate whether or not hognose are venomous, but there is evidence that their saliva has some toxicity to smaller prey items, such as toads and frogs. The fangs have been referred to as just "enlarged teeth", but they are genuine fangs that are used for prey restraint. Despite the common belief, there is no evidence to support the fangs being used for "toad popping". Under this belief, the toads inflate their lungs to make swallowing difficult, but the fangs would penetrate the lungs and deflate them. However, whole toads with intact lungs are commonly regurgitated by recently captured hognoses.
The coloration of this essentially spotted snake is extremely variable,with color phases ranging from yellow and brown to black and gray. The most reliable field work is the turned-up, hoglike snout, which is used for digging out the toads that are its primary food.
Behavior
When threatened, hognose snakes will flatten their necks and raise their heads off the ground, like a cobraCobra
Cobra is a venomous snake belonging to the family Elapidae. However, not all snakes commonly referred to as cobras are of the same genus, or even of the same family. The name is short for cobra capo or capa Snake, which is Portuguese for "snake with hood", or "hood-snake"...
, and hiss. They may sometimes feign strikes, but are not apt to bite. This behaviour has earned them several nicknames, such as "puff adder", "blowing adder", "flathead", "spreadhead", "spreading adder" or "hissing adder". Note, though, the nickname "puff adder" is only a nickname, and is not scientifically correct. There is a highly venomous viper
Viperidae
The Viperidae are a family of venomous snakes found all over the world, except in Antarctica, Australia, Ireland, Madagascar, Hawaii, various other isolated islands, and above the Arctic Circle. All have relatively long, hinged fangs that permit deep penetration and injection of venom. Four...
from Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
called the puff adder, Bitis arietans
Bitis arietans
Bitis arietans is a venomous viper species found in savannah and grasslands from Morocco and western Arabia throughout Africa except for the Sahara and rain forest regions. It is responsible for causing the most fatalities in Africa owing to various factors, such as its wide distribution and...
.
If this threat display does not work to deter a would-be predator
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
, hognose snakes will often roll onto their back and play dead, going so far as to emit a foul musk
Musk
Musk is a class of aromatic substances commonly used as base notes in perfumery. They include glandular secretions from animals such as the musk deer, numerous plants emitting similar fragrances, and artificial substances with similar odors. Musk was a name originally given to a substance with a...
and fecal matter
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
from their cloaca
Cloaca
In zoological anatomy, a cloaca is the posterior opening that serves as the only such opening for the intestinal, reproductive, and urinary tracts of certain animal species...
and let their tongue
Tongue
The tongue is a muscular hydrostat on the floors of the mouths of most vertebrates which manipulates food for mastication. It is the primary organ of taste , as much of the upper surface of the tongue is covered in papillae and taste buds. It is sensitive and kept moist by saliva, and is richly...
hang out of their mouth
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
, sometimes accompanied by small droplets of blood. If they are rolled upright while in this state, they will often roll back as if insisting they really are dead. It has been observed that the snake, while appearing to be dead, will still watch the animal that caused the death pose. The snake will 'resurrect' sooner if the threat is looking away from it than if the threat is looking at the snake.
Video of Display
Diet
HeterodonHeterodon
Heterodon is a genus of harmless colubrids found in North America. They are stout with upturned snouts and are perhaps best known for their characteristic threat displays. Three species are currently recognized.-Description:...
are diurnal active foragers that typically consume their prey live without any constriction or body pinning.
For most hog nose snakes the bulk of their diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
is made up by rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
s, and lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s. H. platirhinos is an exception, and specializes in feeding on toad
Toad
A toad is any of a number of species of amphibians in the order Anura characterized by dry, leathery skin , short legs, and snoat-like parotoid glands...
s although other food items such as eggs, insects and mice can make up as much as 50% of their diet.
In captivity
Hognose snakes are frequently found in the exotic petExotic pet
An exotic pet is a rare or unusual animal pet, or an animal kept as a pet which is not commonly thought of as a pet.The definition is an evolving one; some rodents, reptiles, and amphibians have become firmly enough established in the world of animal fancy to no longer be considered exotic...
trade. H. nasicus are often considered to be the easiest to care for, and captive bred stock is easily found. H. platirhinos is also commonly found, but their dietary requirements can be a challenge for some keepers, and there is anecdotal evidence to suggest that feeding them a diet of exclusively rodents contributes to liver problems and a shortened life span. Leioheterodon species are imported regularly from Madagascar, and are not often bred in captivity and get much larger, so can pose a set of different challenges for care. Lystrophis species are fairly new to the commercial reptile
Reptile
Reptiles are members of a class of air-breathing, ectothermic vertebrates which are characterized by laying shelled eggs , and having skin covered in scales and/or scutes. They are tetrapods, either having four limbs or being descended from four-limbed ancestors...
trade, and are now commonly bred in captivity, but can be some of the more expensive hognose snakes available.
Toxicity
Though not life threatening, they are still potent. Causes swelling and numbness of area of bite. Lasts around three days.Popular culture
- The song "Copperline" by James TaylorJames TaylorJames Vernon Taylor is an American singer-songwriter and guitarist. A five-time Grammy Award winner, Taylor was inducted into the Rock & Roll Hall of Fame in 2000....
contains the lyrics:
- "Half a mile down to Morgan Creek, leaning heavy on the end of the week.
- Hercules and a hognosed snake, down on Copperline, we were down on Copperline."
External links
- http://www.thehognosesnake.co.ukthehognosesnake.co.uk Hognose snakes are really important.
- Hognose.com
- Dutch Breeder of colour mutations of hognose, many pictures
- The European Molecular Biology Laboratory Reptile Database
- *Western Hognose Snake Species account from the Iowa Reptile and Amphibian Field Guide
- *Eastern Hognose Snake Species account from the Iowa Reptile and Amphibian Field Guide