EASTERN HOG-NOSED SNAKE
Latreille (in Sonnini and Latreille), 1801
Kansas Species in Need of Conservation (SINC)
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, irregular shaped blotches on the back and smaller blotches on the sides. 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.
In eastern portions of their range (outside of Kansas) some individuals may be entirely black or dark gray without any pattern.
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..
County Breakdown: County Name (# occurrences)
Allen (1), Barber (8), Barton (1), Cherokee (1), Clark (2), Comanche (5), Cowley (1), Decatur (1), Doniphan (1), Douglas (9), Edwards (2), Ellis (16), Ellsworth (1), Ford (2), Franklin (5), Geary (2), Gove (2), Graham (2), Gray (1), Greenwood (1), Hamilton (7), Harper (5), Harvey (5), Hodgeman (1), Johnson (1), Kearney (4), Kiowa (3), Leavenworth (1), Logan (3), Meade (8), Miami (2), Morton (1), Norton (1), Pawnee (2), Phillips (2), Pottawatomie (1), Pratt (2), Reno (5), Rice (1), Riley (7), Rooks (1), Russell (5), Scott (1), Sedgwick (4), Seward (7), Stafford (6), Sumner (3), Trego (3), Wyandotte (3)
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).
The eastern hognose snake is renowned for its 'death feigning' behavior. When threatened, it flattens its head and neck and hisses loudly. It may strike, but only with its mouth closed. If it is further harassed, it will flip on its back and convulse for a short period and may defecate and regurgitate its food. It will then remain motionless with its belly up, mouth open, and tongue hanging out. It may play dead for several minutes before cautiously turning over, looking around to see if it is safe and then crawling away.
Heterodon means 'different tooth', which refers to the enlarged teeth on the rear of the upper jaw. These teeth inject a mild venom into its prey, and also serve to pop inflated toads like a balloon to enable ingestion. They use their blunt nose to search through leaf litter and soil for prey. The eastern hognose snake specializes in feeding on toads, having an immunity to the toxins toads secrete, but will sometimes eat other frogs, insects, and invertebrates. Juveniles eat small frogs and toads, insects, lizards, and small snakes.
Growth and Longevity:
Average adult size is 20-33 inches (51-84 cm), record is 45.5 inches (115.5 cm).
Pleistocene fossil specimens are known from Meade, Rice, and McPherson counties.
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.
1802. Sonnini, C. S. and P. A. Latreille. Histoire naturelle des Reptiles. Paris, 4. Pp. 1-410.
1969. Platt, Dwight R. Natural history of the hognose snakes Heterodon platyrhinos and Heterodon nasicus. University of Kansas, Museum of Natural History. 18(4): pp. 253-420.
1994. Fitzgerald, Eve and Charles Nilon. Classification of habitats for endangered and threatened species in Wyandotte County, Kansas. Kansas Department of Wildlife and Parks, Pp. 98 pp.
1997. Ahrens, John. Amphibian and reptile distributions in urban riparian areas. Master's Thesis, University of Missouri-Columbia. Pp. 70.