The western hognose snake (''Heterodon nasicus'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of snake in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Colubridae Colubridae (, commonly known as colubrids , from la, coluber, 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest species of the family date back to the Oligocene epoch. Colubrid snakes are found on ever ...

. The species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to North America.

Etymology

The specific name, ''nasicus'', is from the Latin '' nasus'' ("nose"), in reference to the upturned snout. The subspecific name, ''gloydi'', is in honor of

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

herpetologist Herpetology (from Greek ἑρπετόν ''herpetón'', meaning "reptile" or "creeping animal") is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) and rept ...

Howard K. Gloyd Howard Kay Gloyd (February 12, 1902 – August 7, 1978) was an American herpetologist who is credited with describing several new species and subspecies of reptiles, such as the Florida cottonmouth, ''Agkistrodon piscivorus conanti''. Also, he is h ...

(1902–1978).Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). ''The Eponym Dictionary of Reptiles''. Baltimore: Johns Hopkins University Press. Baltimore. xiii + 296 pp. . (''Heterodon nasicus gloydi'', p. 102; ''Heterodon nasicus kennerlyi'', p. 140). The subspecific (or

specific Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the fina ...

) name, ''kennerlyi'', is in honor of American naturalist Caleb Burwell Rowan Kennerly (1829–1861).

Common names

Common names for ''Heterodon nasicus'' include blow snake, bluffer, faux viper, plains hognose snake, prairie hognose snake, spoonbill snake, spreadhead snake, Texas hognose snake, Texas rooter, and western hognose snake.

Taxonomy

Some authors elevate '' H. n. kennerlyi'', also known as the Mexican hognose snake, to species level. Those same authors have subsumed ''H. n. gloydi'' into ''H. nasicus'' so that there are only two species (''H. nasicus'' and ''H. kennerlyi'') and no subspecies.

Description

The western hognose snake is a relatively small, stout-bodied snake. Its color and pattern is highly variable between

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

, although most specimens appear much like

rattlesnake Rattlesnakes are venomous snakes that form the genera ''Crotalus'' and ''Sistrurus'' of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small anim ...

s to the untrained eye, which appears to be

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, after his work on bu ...

. Males are considerably smaller than females, with adults rarely exceeding a total length (including tail) of . This snake gets its common name, "hognose", from the modified rostral (nose) scale that is formed in an upturned manner, providing a very "hog-like" look. Additionally, this adaptation makes these snakes adept burrowers. The species is not dangerous to humans, but there exists scientific debate regarding whether the mild toxins in the hognose's bite result from saliva, harmful to its preferred wild food source –

toads Toad is a common name for certain frogs, especially of the family Bufonidae, that are characterized by dry, leathery skin, short legs, and large bumps covering the parotoid glands. A distinction between frogs and toads is not made in scientif ...

– or an extremely mild venom produced in glands connecting to the hognose's minuscule rear fangs. In either case, no deaths or systemic effects from the extremely rare bite from this rear-fanged snake have been recorded. Although bites may uncommonly be medically significant, the species is not regarded as venomous. In captivity, the species has been bred into about 52 different "designer" color morphs.Berry, John R. (2012). ''Designer-Morphs: Western Hognose Snakes: A complete guide to care, breeding morphs and mutations''. Tom's Reptile Supplies. .

Distribution and habitat

The western hognose snake occurs from southern Canada throughout the United States to northern Mexico. It frequents areas with sandy or gravelly soils, including prairies, river floodplains, scrub and grasslands, semi-deserts, and some semiagricultural areas. It has been found at elevations of up to .

Ecology

Behavior

The western hognose snake is primarily diurnal. It is typically a docile snake (though known to be highly defensive in some individuals). If threatened (or perceiving a threat), it may flatten its neck (much like a cobra), hiss, and make 'mock' or 'bluff' strikes if harassed, which are strikes made at an intruder but with the snakes' mouth closed. Subsequently, even when further harassed, western hognose snakes virtually never bite as a self defense mechanism, but will instead usually resort to playing dead. Although it is more common that it will flatten its head, some individuals may puff up, filling the throat with air. This is more common with adolescent males.

Diet

In the wild, the western hognose snake feeds predominately on

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

s, such as large and medium-sized

tree frog A tree frog (or treefrog) is any species of frog that spends a major portion of its lifespan in trees, known as an arboreal state. Several lineages of frogs among the Neobatrachia have given rise to treefrogs, although they are not closely relat ...

s, as well as small or medium-sized

and small lizards. There have been accounts of ''H. nasicus'' eating the occasional rodent in the wild as well. Not being a true constrictor, ''Heterodon'' bites and chews, driving the rear fangs into the prey as a way of introducing the saliva to help break down the toxins from toads. There have been many cases of hognose snakes in captivity that will not eat for about two to three-and-a-half months, from the months January to mid March. This is because hognose snakes' instinct is to

brumate Dormancy is a period in an organism's life cycle when growth, development, and (in animals) physical activity are temporarily stopped. This minimizes metabolic activity and therefore helps an organism to conserve energy. Dormancy tends to be clos ...

underground during the winter months. Heterodon nasicus2

Reproduction

Adult western hognose snakes have been observed in copulation as early as February and March. The species is

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

, with females laying 4–23 elongate, thin-shelled

egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...

s in June–August. The eggs take approximately 60 days to hatch. Each hatchling is in total length, and reaches sexual maturity after approximately two years (this is predominantly based on size, not so much age). (''Heterodon nasicus'', pp. 613–614 + Plate 572).

Subspecies

Conservation

Although some local declines have been reported, the species ''H. nasicus'' is widespread, has a large overall population size (> 100,000), and is effectively protected by a variety of conservation programs. It is therefore currently classified as

Least Concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

. The eastern hognose snake (''

Heterodon platirhinos The eastern hog-nosed snake (''Heterodon platirhinos''), also known as the spreading adder Wright, A.H., and A.A. Wright (1957). ''Handbook of Snakes of the United States and Canada''. (in 2 volumes). Ithaca and London: Comstock Publishing Assoc ...

'') is classified as a threatened species in some regions of its range and is therefore protected under those states' laws.

References

* Baird SF, Girard C (1852). "Characteristics of some New Reptiles in the Museum of the Smithsonian Institution". ''Proc. Acad. Nat. Sci. Philadelphia'' 6: 68–70. (''Heterodon nasicum'' ic new species, p. 70). *Baird SF, Girard C (1852). ''In'': Stansbury H (1852). ''Exploration and Survey of the Valley of the Great Salt Lake of Utah, Including Reconnoissance'' ic''of a New Route through the Rocky Mountains.'' Philadelphia: Senate of The United States. (Lippincott, Grambo & Co., printers). 487 pp. (''Hetorodon'' ic''nasicus'', pp. 352–353). * Boulenger GA (1894). ''Catalogue of the Snakes in the British Museum (Natural History). Volume II., Containing the Conclusion of the Colubridæ Aglyphæ.'' London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xi + 382 pp. + Plates I–XX. (''Heterodon nasicus'', pp. 156–157). * Conant, Roger; Bridges, William (1939). ''What Snake Is That? A Field Guide to the Snakes of the United States East of the Rocky Mountains''. (with 108 drawings by Edmond Malnate.) New York and London: D. Appleton-Century Company. Frontispiece map + viii + 163 pp. + Plates A–C, 1–32. (''Heterodon nasicus'', pp. 40–41 + Plate 4, Figure 12). *Edgren, Richard A. (1952). "A Synopsis of the Snakes of the Genus ''Heterodon'', with the Diagnosis of a New Race of ''Heterodon nasicus'' Baird and Girard". ''Nat. Hist. Misc., Chicago Acad. Sci.'' 112: 1–4. (''Heterodon nasicus gloydi'', new subspecies). * Kennicott R (1860). "Descriptions of New Species of North American Serpents in the Museum of the Smithsonian Institution, Washington". ''Proc. Acad Nat. Sci. Philadelphia'' 12: 328–338. (''Heterodon kennerlyi'', new species, pp. 336–337). * Powell R, Conant R, Collins JT (2016). ''Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition''. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 plates, 207 figures. . (''Heterodon nasicus'', pp. 407–408, Figure 189 + Plate 39). * Schmidt, Karl P.; Davis, D. Dwight (1941). ''Field Book of Snakes of the United States and Canada''. New York: G.P. Putnam's Sons. 365 pp., 34 plates, 103 figures. (''Heterodon nasicus'', pp. 115–118, Figures 25–26 + Plate 11). * Smith, Hobart M.; Brodie, Edmund D. Jr. (1982). ''Reptiles of North America: A Guide to Field Identification''. New York: Golden Press. 240 pp. (paperback), (hardcover). (''Heterodon nasicus'', pp. 164–167). * Stebbins RC (2003). ''A Field Guide to Western Reptiles and Amphibians, Third Edition''. The Peterson Field Guide Series ®. Boston and New York: Houghton Mifflin. xiii + 533 pp. (paperback). (''Heterodon nasicus'', pp. 347–348 + Plate 47 + Map 129). {{Authority control Colubrids Snakes of North America Reptiles of the United States Reptiles of Canada Reptiles of Mexico Reptiles described in 1852