Pituophis catenifer (Blainville, 1835)
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Basis for Listing
The gophersnake is widely distributed throughout the central and western United States, southwestern Canada, and northern Mexico. It is presently divided into six subspecies (Crother 2008), with the bullsnake (Pituophis catenifer sayi) being the subspecies found in Minnesota. Most of the Minnesota records of this species are from counties along the Minnesota, Mississippi, and St. Croix rivers, although there is an unconfirmed record from Polk County in northwestern Minnesota, where a single specimen was reportedly collected near Fertile in 1939 (Oldfield and Moriarty 1994). The gophersnake is considered a desirable pet species, and while many animals in the pet trade are captive bred, many are collected from the wild. The primary threat to this species is habitat loss and degradation from agriculture, urban sprawl, and lack of fire.
The gophersnake is a large, heavy bodied snake. Adults range from 94-183 cm (37-72 in.) long (Conant and Collins 1991), with the record being 254 cm (100 in.) long (Harding 1997). The Minnesota record is a female from Wabasha County that measured 188 cm (74 in.) long (Oldfield and Moriarty 1994). The base color of this snake's back is usually a straw yellow, which is marked with a series of black to brown blotches that transition to a banded pattern on the tail. The head is yellow with irregular dark markings and a pointed nose. The chin and belly are pale yellow, and the belly has scattered black or brown mottled rectangles. The scales are heavily keeled and the anal plate is single. Young gophersnakes have a pattern similar to adults, but their coloration is lighter (Oldfield and Moriarty 1994). The gophersnake resembles the western foxsnake (Pantherophis vulpinus), but adult foxsnakes have a solid brown or reddish-brown, unmarked head and a rounded nose (Oldfield and Moriarty 1994).
The gophersnake prefers areas of well-drained, loose sandy and gravel soils. Dry sand prairies and bluff prairies are prime habitat. Hibernation sites include rodent burrows and rock fissures in bluffs and outcrops. Females will nest in old mammal burrows or excavate a nest chamber in sandy soils.
Biology / Life History
The gophersnake is a permanent resident, emerging from hibernation in the spring. Breeding takes place in the spring and the males may engage in a combat ritual. From 3-24 eggs are laid in June or early July in a nest excavated by the female under a large rock or log (Oldfield and Moriarty 1994). The eggs will hatch in 56-100 days, and the young are 25.5-44 cm (10-17 in.) long and are precocial (Oldfield and Moriarty 1994). The gophersnake feeds on a variety of small animals, including gophers, mice, voles, ground squirrels, tree squirrels, frogs, and ground nesting birds. Bird eggs may also be consumed (Oldfield and Moriarty 1994). Gophersnakes will try to escape when encountered, but if cornered, they will hiss, vibrate their tail, and strike. The vibrating tail can make a sound resembling that of a rattlesnake, especially if the snake is in dry leaves, but the gophersnake is a nonvenomous species. The gophersnake is normally a solitary species, but it may hibernate in groups, sometimes with other species such as timber rattlesnakes (Crotalus horridus) where their ranges overlap.
Conservation / Management
While the gophersnake is collected for the pet trade, the major threat to its conservation is habitat destruction and degradation. Historically, agriculture was the primary threat, but today urban sprawl and lack of fire, which allows habitats to become overgrown with woody species, top the list. While fire is beneficial to maintaining open habitats, fires over several consecutive years or conducted at the wrong time of year could have a negative impact on snake populations. General prescribed burning guidelines have been developed for amphibians and reptiles in the Midwest, although land managers conducting burns in areas with known rare reptile or amphibian species or high concentrations of reptiles and/or amphibians may wish to contact their Regional Nongame Wildlife Specialist for input on burn planning, including timing of burns, so as to minimize impacts on these species.
Conservation Efforts in Minnesota
All of the counties within the known range of the gophersnake in the state have been surveyed by the Minnesota Biological Survey. Field surveys where the species was reportedly found in Polk County failed to find another specimen. In 1991, a reintroduction effort was undertaken in Hennepin County with some success (Moriarty 1991). Fortunately, many of the gophersnakes records in Minnesota are from public lands where habitat is generally protected.
Conant, R., and J. T. Collins. 1991. A field guide to reptiles and amphibians of eastern and central North America. Third edition. Houghton Mifflin Company, Boston, Massachusetts. 450 pp.
Crother, B. I., editor. 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Sixth Edition. Society for the Study of Amphibians and Reptiles Herpetological Circular 37. 94 pp.
Harding, J. H. 1997. Amphibians and reptiles of the Great Lakes Region. The University of Michigan Press, Ann Arbor, Michigan. xvi + 378 pp.
Moriarty, J. J. 1991. Reintroduction of Bullsnakes into the Crow-Hassan Prairie restoration. Final report submitted to the Nongame Wildlife Program, Minnesota Department of Natural Resources. Unpaged.
Oldfield, B., and J. J. Moriarty. 1994. Amphibians and reptiles native to Minnesota. University of Minnesota Press, Minneapolis, Minnesota. 237 pp.