Western Hognose Snake (Heterodon nasicus) 



Description: The Western Hognose Snake is a mid-sized, heavy-bodied snake reaching 32". The 

 dorsal ground color is yellowish- to grayish-brown, with 3 rows of darker brown to black 

 blotches running down the back. The belly is dark gray to black, sometimes checkered. Its 

 nose has a keel on the top and is upturned. 



Eggs and Young: Clutches have 7-15 eggs which are white and elliptical, with thin, papery 

 shells; length averages 32.5 mm (26-38 mm) and width 18 mm (14-23 mm). Young are 139- 

 197 mm at hatching and are similar in color and pattern to adults (Piatt 1969). 



Similar Species: No other Montana snake has a keeled nose. Coloration is similar to both the 

 Gopher Snake, Western Rattlesnake and juvenile Racer. 



Habits and Habitat: The Western Hognose Snake is found on the plains of eastern Montana. It 

 seems to prefer arid areas, farmlands and floodplains, and particularly areas of gravelly or 

 sandy, loose soil. The keeled or shovel-like nose is thought to help it to dig down to its food, 

 which it finds by smell. Apparently toads are its preferred food, though frogs, insects, and 

 other small animals are also eaten (Piatt 1969). It is active primarily during the daylight 

 hours. Little is known of reproduction in Montana. It is likely that a female will only breed 

 every other year in Montana. 



The Hognose is famous for its behavior in the face of a threat. At first it will puff up its 

 neck, as does a cobra, and hiss and strike at its enemy. However, this is all a bluff; very 

 rarely will it actually bite. If this threatening strategy does not work, it will pretend to die. It 

 appears to go into convulsions, writhing on the ground, sticking its mouth in the dirt, and 

 eventually rolling on its back and going into a trance that makes it appear to be dead. If 

 turned right-side-up, it will roll back over and continue its deception. If left alone for a few 

 minutes, it will right itself and continue on its way. The initial aggressive display and basic 

 rattlesnake-like coloration cause many to be killed needlessly by people who mistakenly 

 believe it to be venomous. 



Surveying: They may be surveyed for by slowly walking through appropriate habitat and 

 carefully watching for them; conducting surveys on warm, sunny days enhances sampling 

 success. However, as with many lizards and snakes, they may easily be missed. Carefully- 

 documented incidental observations may provide the best clues to their distribution. They 

 may be also taken in pitfall or fiinnel traps with drift fences. Mark-recapture methods offer 

 the best opportunity for determining population status. 



Status: They were not found on the Sioux-CNF during this survey, however one was found a few 

 miles north of the Long Pines near Mill Iron, and there is an historic record south of the Long 

 Pines. Visher (1914) reports them as "fairly frequent on the sandy portions of the 

 floodplains" in Harding County. They may occur on the Sioux-CNF, particularly in sandy or 

 loose soil areas. They should be watched for on the Sioux-CNF; any sightings should be 

 documented. We have relatively few reports of the Western Hognose Snake from Montana. 

 It is collected for the pet trade, and populations may be vulnerable to commercial collectors. 

 Additionally, since toads are its preferred food, any decline in toad populations would be 

 expected to negatively impact Western Hognose Snakes. Of particular interest would be 

 documentation of any denning sites located. 



Montana Natural Heritage Program Rank: G5 S3? A Species of Special Concern. 



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