Occurrences

Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

This snake usually occurs in moist, grassy habitats such as prairies, savannas, meadows, old fields, pastures, roadsides, vacant lots, stream borders, and marsh and lake edges. They also can be found in open moist deciduous and pine forests and along forest edges. They will forage, bask on, and/or hide in or under stumps, logs and other woody debris, low shrubs, rocks, or anthropogenic debris such as boards or concrete. They lay their eggs in or under rotting wood, underground in burrows, or under logs, rocks, boards or other similar cover objects. They overwinter in abandoned ant hills and small mammal burrows. They may hibernate communally with other small snakes.

Natural Community Types

• Coastal fen
• Dry-mesic northern forest
• Dry-mesic prairie
• Dry-mesic southern forest
• Lakeplain oak openings
• Lakeplain wet prairie
• Lakeplain wet-mesic prairie
• Mesic northern forest
• Mesic prairie
• Mesic sand prairie
• Mesic southern forest
• Northern fen
• Northern wet meadow
• Oak barrens
• Oak-pine barrens
• Pine barrens
• Prairie fen
• Southern shrub-carr
• Southern wet meadow
• Wet prairie
• Wet-mesic prairie
• Wet-mesic sand prairie

Methodology

Management Recommendations

Main threats to this species are pesticide use and habitat loss due to conversion to intensive agricultural use. Because this species feeds primarily on insects, they are particularly vulnerable to the direct and indirect effects of pesticides that are widely sprayed in agricultural areas as well as residential areas. Maintaining and protecting suitable habitats within extant populations are critical to conservation of this species. Minimizing the use of pesticides within and adjacent to occupied habitats would help maintain sufficient prey and reduce the potential for adverse impacts to extant populations of this species. Targeted surveys and research are needed to obtain enhanced information and a better understanding of this species’ current status and distribution, ecology, particularly habitat requirements, and specific threats facing the state’s remaining populations. Surveys to assess and monitor the prevalence of snake fungal disease in extant populations also are needed to assess impact of this disease and determine if and when management is warranted.

Active Period

Active from second week of April to fourth week of October

Breeding from third week of April to fourth week of August

Nesting from third week of June to second week of September

Survey Methods

Surveys can be conducted any time during the active season. The best way to survey for this species is with visual surveys in which observers walk slowly through areas with suitable habitat looking for snakes primarily under cover objects (e.g., downed woody debris, stumps, logs, rocks, etc.) as well as individuals basking, resting, foraging, or moving on the surface. Artificial cover surveys which consist of placing and checking coverboards (e.g., plywood) in the field also may be effective and could complement visual surveys. Surveys should be conducted under appropriate weather conditions during which the species is expected to be active and/or visible (i.e., between 60-80°F [16-27°C], wind less than 15 mph, no or light precipitation). Multiple survey visits to the same site should be conducted.

Cover board survey

Survey Period: From second week of April to fourth week of October

Time of Day: Daytime
Air Temperature: Above 60 degrees
Precipitation: Just after rain
Wind: No Wind

Visual encounter surveys

Survey Period: From second week of April to fourth week of October

Time of Day: Daytime
Air Temperature: Above 60 degrees
Precipitation: Just after rain
Wind: No Wind

References

Survey References

• Graeter, G.L., K.A. Buhlmann, L.R. Wilkinson, and J.W. Gibbons (editors). 2013. Inventory and Monitoring: Recommended Techniques for Reptiles and Amphibians. Partners in Amphibian and Reptile Conservation Technical Publication IM-1, Birmingham, AL. 321 pp.

• Karns, D.R. 1986. Field Herpetology: Methods for the Study of Amphibians and Reptiles in Minnesota. Occ. Pap. No. 18. J.F. Bell Museum of Natural History, University of Minnesota, Minneapolis.

Technical References

• Animal Diversity Web. “Opheodrys vernalis" (On-line), Accessed March 29, 2020 at https://animaldiversity.org/accounts/Opheodrys_vernalis/

• Ernst, C.H., and E.M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Books, Washington, D.C.

• Harding, J.H., and D.A. Mifsud. 2017. Amphibians and Reptiles of the Great Lakes Region, Revised Edition. University of Michigan Press, Ann Arbor, MI. 408 pp.

• NatureServe Explorer 2.0. 2020. <https://explorer.natureserve.org/> NatureServe, Arlington, VA. Accessed 29 Mar 2020.