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Western Hognose Snake

Western hognose snakeAKA Plains Hognose

Order:  Squamata - snakes & lizards

Family:  Colubridae

Scientific name:  Heterodon nasicus  

 

Description:  The snout of the Western Hognose Snake is sharply turned up (hence its name).  The body varies from gray to light yellow to brown, with dark brown blotches down the back and smaller ones on the sides.  Adult males have few blotches on the back and have longer tails than females. The belly has jet-black patches similar in appearance to piano keys.  Scales are keeled, thus rough to touch.  Adults usually grow from 14¾ inches to 27-5/8 inches. Females grow larger than males.   The largest specimen from Kansas was a female measuring 30¼.  Maximum size for this species is 35¼”.
    
RangeRange:  This snake lives throughout the western two thirds of Kansas, reaching peak abundance on High Plains ranging to Flint Hills.  Also occurs in New Mexico, the Texas panhandle and western Oklahoma, north to southern Canada.

 

Habitat:  Prairies, abandoned farmland, sparsely wooded flood plains, especially in areas of sandy or friable soil.

 

Reproductive Habits:  This snake usually mates in May after emergence from winter inactivity (on rare occasions will mate in the fall).  The number of eggs in the clutch varies from 4-23; the average is 9 eggs.  The eggs are laid in July in nests a few inches below the soil.  The 7” hatchlings emerge after about a two-month incubation period.  Females probably deposit a clutch every other year.  Their courtship has not been observed.

 

Diet in WildThey forage for small rodents, nesting birds, lizards and especially amphibians (frogs and toads).  Will occasionally eat small snakes and reptile eggs.  It detects prey by smell, digging a food item from its burrow beneath the soil, issuing its spade-like snout.

 

Diet in ZooMice and toads.

 

General InfoThe western performs a similar but less drastic defense procedure than its relative the eastern hognose.  The western usually does a slight spreading of the hood by flattening its neck giving the impression of a cobra, hissing softly, and if at all possible, quickly leaving the area.  Occasionally it may strike at an intruder, but in all instances, the strike is short and the mouth is closed.  If this fails to frighten off the intruder, it will writhe and contort, disgorge recently eaten food and roll over on its back and play dead.  It may remain “dead” for up to 5 minutes.  If left alone it rights itself and crawls away.   It detects its prey by smell, digging a food item from its burrow beneath the soil.  The upturned snout makes it very efficient at digging up toads, etc.  The generic name Heterodon means “different tooth”, a reference to enlarged rear teeth on the upper jaw that serve to introduce mild venom into prey.  It also is an adaptation that allows this species to puncture toads in order to swallow them, because toads typically inflate their bodies with air when threatened or captured.  The Western hognose is active from mid-April to October at temperatures between 70-95 degrees Fahrenheit.  They are diurnal and are active primarily in late morning and late afternoon.

 

Predators:   The Western hognose snake is preyed upon by medium sized mammals and raptors.

 

Bibliography

Amphibians & Reptiles in Kansas. 3rd Edition Revised. Joseph T. & Suzanne L. Colling.  University of Kansas, Museum of Natural History. 1993.  pp. 190-195.

 

The Encyclopedia of Snakes. Chris Mattison. Checkmark Books. New York, NY. 1995. pp. 218-219.