Western hognose snake
|Western hognose snake|
|Western hognose snake|
Baird & Girard, 1852
Heterodon nasicus, commonly known as the western hognose snake, is a species of harmless colubrid endemic to North America. Western hognose snakes are relatively small, stout-bodied snakes found throughout the Great Plains states of the United States from Canada to Mexico. Their color and pattern is highly variable from subspecies to subspecies, although most specimens appear much like the infamous rattlesnake to the untrained eye. This optical bluff, used in conjunction with a wide array of other clever defense tactics, makes these snakes unique among North American serpents.
Although there is still debate whether Heterodon is mildly venomous or nonvenemous with toxic saliva, it is generally agreed that the species is indeed venomous. Regardless, the extremely rare bite from this rear-fanged snake is of no medical importance to humans. Symptoms range from negligible to localized slight swelling and itching. As with any animal though, care must be taken not to receive a bite as allergic reactions and infection are always a slight possibility.
Males are considerably smaller than females, with adult lengths rarely exceeding 15-20 inches.
These snakes get their common name 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, which is a useful skill when hunting or seeking refuge from the elements.
Interaction with humans
Even though this snake does not cause harm to humans, people are the snake's biggest threat. People often mistake the hognose for a rattlesnake, killing it to protect themselves. Educating people that the hognose snake is harmless will increase the survival of the species. The eastern hognose snake (Heterodon platirhinos) is classified as a threatened species in some regions of its range and is therefore protected under those state's laws. Because the eastern and western species of hognose snakes are so similar in appearance, it would be wise to leave all hognose individuals alone in the wild.
Blow snake, bluffer, (western) hognose snake, faux viper, prairie hognose snake, spoonbill snake, spreadhead snake, Texas hognose snake, Texas rooter.
The western hognose snake is primarily diurnal. It is typically a docile snake (though known to be highly aggressive in some individuals). If threatened (or perceiving a threat), it may flatten its neck (much like a cobra), hiss, and make mock strikes if harassed. Occasionally, if stressed enough, it even plays dead. Although it is more common that they will flatten their heads out, some individuals may puff up, filling their throats with air. This is more common with adolescent males. In some rare cases the snake will use its rear hinged fangs to inject a semi harmful venom the snake injects by chewing. Most wet (venomous) bites will not do much more than swell, but in extreme cases the victim will experience organ failures, such as kidney or liver failure..
In the wild, they feed predominately on amphibians, such as large and medium-sized tree frogs, as well as small or medium-sized toads 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/"venom" into the bloodstream in order to incapacitate its meal. 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 hibernate underground during the winter months.
Western hog-nosed snakes have been observed in copulation as early as February and March. They are oviparous, with females laying 4-23 elongate, thin-shelled eggs in June–August. The eggs take approximately 60 days to hatch. Hatchlings are 13-23 cm (5–9 inches) in total length and reach sexual maturity after approximately two years (this is predominantly based on size, not so much age).
This species is more commonly kept and bred in captivity than any other member of its genus and makes for a wonderful terrarium pet. It is small, hardy and docile by nature. Commercially available rodents are readily consumed and not much space or specialized care is required. It is also bred commercially with many color variations available.
|Subspecies||Authority||Common name||Geographic range|
|H. n. gloydi||Edgren, 1952||Gloyd's hog-nosed snake||United States: southeastern Kansas and southeastern Missouri, eastern Oklahoma and all of Texas excluding the panhandle, trans-pecos Texas and the extreme southern Rio Grande Valley.|
|H. n. kennerlyi||Kennicott, 1860||Kennerly's hog-nosed snake||Mexico from Tamaulipas and central San Luis Potosí, north and west along the Sierra Madre Occidental, entering the United States in the extreme south of the Rio Grande Valley, trans-pecos Texas, southwestern New Mexico and southeastern Arizona.|
|H. n. nasicus||Baird & Girard, 1852||Western hog-nosed snake||Texas panhandle and adjacent New Mexico, north through western Oklahoma and Kansas to southwestern Manitoba and southeastern Saskatchewan in Canada. Also occurs in prairie regions of Minnesota and prairie relicts of Illinois.|
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 2 species (H. nasicus and H. kennerlyi) and no subspecies.
- Behler JL, King FW. 1979. The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf. 743 pp. LCCCN 79-2217. ISBN 0-394-50824-6.
- "Heterodon nasicus". Integrated Taxonomic Information System. Retrieved 28 November 2006.
- Wright AH, Wright AA. 1957. Handbook of Snakes of the United States and Canada. Comstock Publishing Associates. Ithaca and London. (7th printing, 1985). 1,105 pp. (in 2 volumes) ISBN 0-8014-0463-0. (Heterodon nasicus nasicus, pp. 297-301, Figure 91, Map 28.) (Heterodon nasicus kennerlyi, pp. 301-304, Figure 92 + Map 28 on p. 298.) (Heterodon nasicus gloydi, p. 304 + Map 28 on p. 298.)
|Wikimedia Commons has media related to Heterodon nasicus.|
- Heterodon nasicus at the Reptarium.cz Reptile Database. Accessed 14 September 2007.
- Heterodon nasicus at Herps of Texas. Accessed 14 September 2007.
- Heterodon nasicus at Illinois Natural History Survey. Accessed 14 September 2007.
- Heterodon nasicus at Animal Diversity Web. Accessed 14 September 2007.
- Heterodon nasicus at Kansas Herpetofaunal Atlas: . Accessed 14 September 2007.
- General care guide for H. n. nasicus, at Animal Allsorts. Accessed 14 September 2007.
- Western Hognose Snake at Herpnet.net. Accessed 14 September 2007.
- Western Hognose Snake Care Guide at .
- Baird, S.F., and C. Girard. 1852. Characteristics of some New Reptiles in the Museum of the Smithsonian Institution.
Proc. Acad. Nat. Sci. Philadelphia 6: 68-70. (Heterodon nasicum [sic], p. 70.)
- Baird, S.F., and C. Girard. 1852. In Stansbury, H. 1852. Exploration and Survey of the Valley of the Great Salt Lake of Utah, Including Reconnoissance [sic] of a New Route through the Rocky Mountains. Senate of The United States. Lippincott, Grambo & Co., Printers. Philadelphia. 487 pp.
(Hetorodon [sic] nasicus, pp. 352-353.)
- Conant, R., and W. Bridges. 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.) D. Appleton Century. New York and London. Frontispiece map + viii + 163 pp. + Plates A-C, 1-32. (Heterodon nasicus, pp. 40-41 + Plate 4, Figure 12.)
- Edgren, R.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)
- 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, pp. 336-337.)