Heterodon platirhinos
Latreille (in Sonnini and Latreille) 1801

hĕ-tĕr-ō-dŏn — plă-tĕ-rhī-nŏs

Kansas Species in Need of Conservation (SINC)

An adult Eastern Hog-nosed Snake from Comanche County. © Maci Loughrea.
An adult Eastern Hog-nosed Snake from Logan County. © John Kraft.
An adult Eastern Hog-nosed Snake from Ellis County, Kansas. Image © Lisa Wehrly.
Adult Eastern Hog-nosed Snake from Ellis County.  © Jacob Basler.
An adult from Barber County. Image © Suzanne L. Collins, CNAH.
An adult from Gove County. Image © Suzanne L. Collins, CNAH.
An adult from Gove County. Image © Suzanne L. Collins, CNAH.

HARMLESSLY VENOMOUS. Uses its venom to subdue prey, but is not dangerous to humans because a) they have an ineffective venom delivery mechanism, b) their mouths too small to gain purchase, and c) their venom is not adapted for causing physiological damage to mammals. 
Upturned snout; rough scales; underside of tail much lighter in color than the belly. Highly variable in color. Back, head and tail may be yellow, brown, tan, reddish, olive or gray, with 20–30 dark brown or black blotches on the back and similarly colored bands on the tail. Sides of the body with 2–3 series of small, dark spots alternating with the blotches on the back. Belly may be yellowish, gray, olive or reddish; becomes darker toward the rear. Young same as adults.
It has a thick body and slightly upturned, pointed snout. Adult coloration is extremely variable and may be mostly yellow, tan, olive, brown, gray, orange, or reddish-brown with dark brown or black large, irregularly shaped blotches on the back and smaller blotches on the sides. Melanistic (dark-brown to black) specimens are common to the east but have never been reported from Kansas. The belly may be yellow, light gray, or pinkish and may or may not be mottled gray or greenish. The underside of the tail is lighter than the rest of the belly. There is a dark line extending from the upper jaw through the eye. The scales are keeled, and there are 23-25 dorsal scale rows at midbody. The pupil is round.
Adults normally attain 510-760 mm (20-30 inches) in TL; largest specimen from Kansas: female (KU 221200) from Harper County with TL of 1,097 mm (43 1/8 inches) collected by Kevin Albright on 23 August 1992; maximum length throughout range: 45½ inches (Conant and Collins, 1998).

This species is spottily distributed in the eastern half of Kansas but is rather well-documented along riparian zones south and west of the Arkansas River valley and in the Smoky Hills. Pleistocene fossil specimens are known from Meade, Rice, and McPherson counties.

(, Museum Voucher) (, Observation) (, Literature Record)
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  • Occurrence Summary:  
  • 183 Total Records 
  • 157 Museum Vouchers 
  • 26 Other Observations 
Some county occurrences indicated below may be too imprecise to map above.
County Breakdown: County Name (# occurrences):
Allen (1); Barber (10); Barton (1); Cherokee (2); Clark (4); Comanche (6); Cowley (2); Crawford (1); Decatur (2); Doniphan (1); Douglas (9); Edwards (2); Ellis (19); Ellsworth (1); Finney (1); Ford (2); Franklin (5); Geary (3); Gove (2); Graham (2); Gray (1); Greenwood (1); Hamilton (8); Harper (7); Harvey (6); Hodgeman (1); Johnson (1); Kearney (4); Kiowa (3); Leavenworth (3); Logan (3); Meade (6); Miami (2); Morton (1); Norton (1); Pawnee (2); Phillips (1); Pottawatomie (1); Pratt (2); Reno (7); Rice (2); Riley (8); Rooks (2); Russell (5); Scott (2); Sedgwick (5); Seward (7); Stafford (6); Sumner (3); Trego (3); Wyandotte (3);

Natural History:
Lives in forested areas of eastern Kansas west along major streams to the Colorado border. Prefers sandy areas stretches along valleys of major rivers. Active from late April to October. Mating occurs during April and May; a single clutch of 4-61 eggs is laid; eggs are deposited in late June or July; incubation requires 50–65 days. Never bites. Feeds primarily on toads. When first encountered, spreads hood, hisses, lunges at an intruder and eventually rolls over and “plays dead.”
It lays eggs. Breeding takes place in both the spring and fall. Males often follow the female around for several days prior to courtship and copulation. They lay between 4-61 whitish, thin-shelled, leathery eggs 1.25 inches (3.2 cm) long. Eggs are deposited in a moist sandy, shallow hole, or under debris, and hatch in 39-65 days. Hatchlings are 6.5-9.5 inches (16-24 cm).

Occurrence Activity:
Hog-nosed Snakes are in the genus Heterodon, (= different tooth). They have an enlarged tooth on each side toward the rear of their upper jaws. The hypothesized function is to aid the ingestion (actually deflation) of toads (their preferred food). When captured, toads fill themselves up with air, making themselves much bigger (and more difficult to swallow). The enlarged teeth are not connected to a venom delivery system.
Hog-nosed (and many other 'harmless') snakes may technically produce venom in their saliva... however, they should not be considered dangerous or venomous. They lack the efficient venom delivery systems of the pit-vipers (rattlesnakes, copperheads, etc.) and their venom is of such a small quantity, w/ high prey specificity, and/or low toxicity. They are also behaviorally reluctant to bite. Nearly all envenomations result from accidents during the feeding of a pet snake, combined with hypersensitivity to the saliva on the part of the bitten person. In any case, the worst symptoms include localized swelling, slight discoloration/bruising, and the formation of small blisters.
The records from the Flint Hills east are in need of corroboration, particularly the Greenwood County specimen (KU 18115) collected in 1933. Fitzgerald and Nilon (1994) and Ahrens (1997) reported recent examples of this snake from Camp Naish in urban Wyandotte County. West of the Flint Hills this taxon is locally abundant, particularly in sandy areas, such as alluvial corridors and stabilized dune sands. These areas also support healthy populations of Bufo woodhousii and B. cognatus, the preferred food of the Eastern Hognose Snake.
William L. Hoyle observed an Eastern Hog-nosed Snake in an orchard in a sandy area in Cowley county on April 30, 1933, just as it was in the act of stalking a Prairie Lizard (Sceloporus consobrinus). Damp sand was still on the snake's back and the snake's track was traced back to the entrance of a hole about six feet away, where digging disclosed the den, which was about three feet long and about eight inches deep. The hole averaged about three inches in diameter (Burt and Hoyle, 1935).

1801 Latreille, Pierre Andr. XXII Genre. Hétérodon, Heterodon. Pages 32-37 in Sonnini and Latreille, Histoire Naturelle des Reptiles avec figures dessinées d’après nature, Vol. 4: Chez Deterville, Paris, France.. pp.
1877 Mozley, Annie E List of Kansas snakes in the museum of the Kansas State Univeristy Transactions of the Kansas Academy of Science 6():34-35
1904 Branson, Edwin B. Snakes of Kansas. University of Kansas Science Bulletin 2(13):353-430
1917 Wooster, Lyman D. Nature Study Bulletin Kansas State Printing Plant, Topeka, Kansas.. 63pp.
1928 Burt, Charles E. Some distributional and ecological records of Kansas reptiles. Transactions of the Academy of Science St. Louis 26():186-208
1929 Taylor, Edward H. A revised checklist of the snakes of Kansas. University of Kansas Science Bulletin 19(5):53-62
1929 Taylor, Edward H. List of reptiles and batrachians of Morton County, Kansas, reporting species new to the state fauna. University of Kansas Science Bulletin 19(6):63-65
1932 Gloyd, Howard K. The herpetological fauna of the Pigeon Lake Region, Miami County, Kansas. Papers of the Museum of Zoology, University of Michigan 15():389-408
1934 Brennan, Lawrence A. A check list of the amphibians and reptiles of Ellis County, Kansas. Transactions of the Kansas Academy of Science 37():189-191
1935 Brennan, Lawrence A. Notes on the Distribution of Amphibia and Reptilia of Ellis County, Kansas. Thesis. Fort Hays State University, Hays, Kansas. 114pp.
1935 Burt, Charles E. Further records of the ecology and distribution of amphibians and reptiles in the middle west. American Midland Naturalist 16(3):311-366
1935 Burt, Charles E. and William L. Hoyle. Additional records of the reptiles of the central prairie region of the United States Transactions of the Kansas Academy of Science 37():193-216
1937 Brennan, Lawrence A. A study of the habitat of reptiles and amphibians of Ellis County, Kansas. Transactions of the Kansas Academy of Science 40():341-347
1950 Smith, Hobart M. Handbook of Amphibians and Reptiles of Kansas. University of Kansas, Museum of Natural History, Miscellaneous Publication (2):336
1956 Smith, Hobart M. Handbook of Amphibians and Reptiles of Kansas. Second edition. University of Kansas Museum of Natural History Miscellaneous Publication (9):1-356
1962 Gish, Charles D. The Herpetofauna of Ellis County, Kansas. Thesis. Fort Hays State University, Hays, Kansas. 34pp.
1969 Platt, Dwight R Natural history of the hognose snakes Heterodon platyrhinos and Heterodon nasicus University of Kansas, Museum of Natural History 18(4):253-420
1974 Collins, Joseph T. Amphibians and Reptiles in Kansas University of Kansas Museum of Natural History Public Education Series (1):283 pp
1981 Blem, Charles R. Heterodon platyrhinos. Catalogue of American Amphibians and Reptiles (282):1-2
1982 Collins, Joseph T. Amphibians and Reptiles in Kansas. 2nd ed. University of Kansas Museum of Natural History Public Education Series (8):
1983 Collins, Joseph T. New records of fishes, amphibians, and reptiles in Kansas for 1982 . Technical Publication of the State Biological Survery of Kansas 13():9-21
1983 Platt, Dwight R. Heterodon. Catalogue of American Amphibians and Reptiles (315):1-2
1989 Platt, Dwight R. Seasonal activity of snakes on a sand prairie. Pages 251-254 in Proceedings of the 11th North American Prairie Conference University of Nebraska Press, Lincoln. pp.
1992 Taggart, Travis W. Heterodon platirhinos. Geographic distribution. Herpetological Review 23():91
1992 Taggart, Travis W. Observations on Kansas amphibians and reptiles Kansas Herpetological Society Newsletter (88):13-15
1993 Collins, Joseph T. and Suzanne L. Collins. Amphibians and Reptiles in Kansas. Third Edition. University Press of Kansas, Lawrence, Lawrence. 397pp.
1993 Freeman, Craig C. and William H. Busby. A survey for endangered and threatened species on the Sunflower Army Ammunition Plant, Johnson County, Kansas. Report No. 54. Kansas Biological Survey, Lawrence. 115pp.
1994 Fitzgerald, Eve and Charles Nilon Classification of habitats for endangered and threatened species in Wyandotte County, Kansas Kansas Department of Wildlife and Parks, Pratt, Kansas. 98pp.
1997 Ahrens, John Amphibian and reptile distributions in urban riparian areas. Thesis. University of Missouri, Columbia, Missouri. 70pp.
2000 Taggart, Travis W. Biogeographic analysis of the reptiles (Squamata) in Ellis County, Kansas. Kansas Herpetological Society Newsletter (121):7-16
2004 Delisle, Jennifer M. and William H. Busby Biological inventory for vertebrates at Fort Larned National Historic Site of the southern plains network. Natural Heritage Inventory, Kansas Biological Survey, Lawrence. 61pp.
2006 Taggart, Travis W. Distribution and status of Kansas herpetofauna in need of information. State Wildlife Grant T7. Kansas Department of Wildlife and Parks, Pratt. vii + 106pp.
2010 Collins, Joseph T., Suzanne L. Collins, and Travis W. Taggart. Amphibians, Reptiles, and Turtles of Kansas Eagle Mountain Publishing., Provo, Utah. 400pp.
2012 Rohweder, Megan R. Spatial conservation prioritization of Kansas for terrestrial vertebrates. Thesis. Fort Hays State University, Hays, Kansas. 151pp.
Account Last Updated:
5/14/2019 12:10:55 PM

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