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Invasive and nonnative animals in Wisconsin

Last checked November 3, 2026 against official sources.

On this page
  1. Spongy moth
  2. Emerald Ash Borer
  3. Checklists of Wisconsin Vertebrates (PUB-SS-954), Watermolen and Murrell
  4. Nuisance wildlife
  5. How to report
  6. Sources

4 nonnative animals are named on 4 official lists for Wisconsin: “Spongy moth” (Wisconsin Department of Natural Resources), “Emerald Ash Borer” (Wisconsin Department of Natural Resources), “Checklists of Wisconsin Vertebrates (PUB-SS-954), Watermolen and Murrell” (Wisconsin Department of Natural Resources, Bureau of Integrated Science Services) and “Nuisance wildlife” (Wisconsin Department of Natural Resources).

To report a sighting, see how to report.

Being on a list of nonnative species does not always mean an animal is harmful or established: each list below is described in its source's terms. A sighting of a listed animal is still worth reporting to the agency.

Spongy moth

Wisconsin Department of Natural Resources, undated page. 1 animal.

Emerald Ash Borer

Wisconsin Department of Natural Resources, undated page. 1 animal.

Checklists of Wisconsin Vertebrates (PUB-SS-954), Watermolen and Murrell

Wisconsin Department of Natural Resources, Bureau of Integrated Science Services, 2001. 1 animal.

Nuisance wildlife

Wisconsin Department of Natural Resources, undated page. 1 animal.

How to report a sighting in Wisconsin

Rattlesnake sightings: call DNR 1-888-WDNRINFO (1-888-936-7463), or use the DNR Rare Species Observation Form / DNR Wildlife Switchboard ([email protected], 608-267-0866). Threatening wolves or wolf depredation: USDA-Wildlife Services (north 1-800-228-1368, south 1-800-433-0663). Spongy moth outside quarantined counties: 1-800-642-MOTH (6684). Other invasive species: DNR Report invasive species page. Feral pig sightings: DNR reporting form or USDA Wildlife Services (north 800-228-1368, south 800-433-0663). Wisconsin Department of Natural Resources, Bureau of Endangered Resources

Do not try to catch or handle the animal. A photo taken from a safe distance, the place and the date help the agency.

Sources

  1. Spongy moth. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
    Quoted passages (1)
    “The European spongy moth (Lymantria dispar) was introduced into Massachusetts in 1869.”
  2. Emerald Ash Borer. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
    Quoted passages (1)
    “Emerald ash borer (Agrilus planipennis) is an invasive, wood-boring beetle that kills ash trees (Fraxinus spp.) by eating the tissues under the bark.”
  3. Checklists of Wisconsin Vertebrates (PUB-SS-954), Watermolen and Murrell. Wisconsin Department of Natural Resources, Bureau of Integrated Science Services. 2001; checked November 3, 2026.
    Quoted passages (1)
    “An unknown number of the non-native Beech Marten (Martes foina; also referred to as the Stone Marten) were released from a fur farm and are now established in and around the southern unit of the Kettle Moraine State Forest (Jefferson, Racine, Waukesha, and Walworth counties)”
  4. Nuisance wildlife. Wisconsin Department of Natural Resources. undated page; checked November 3, 2026.
    Quoted passages (1)
    “The Wisconsin DNR has adopted the position that feral pigs are exotic, non-native animals that pose significant threats to both the environment and to agricultural operations.”
  5. Amphibian and Reptile Frequently Asked Questions #4 - Snakes, PUB-ER-670. Wisconsin Department of Natural Resources, Bureau of Endangered Resources (Kapfer 2011). 2011; checked November 3, 2026.
    Quoted passages (1)
    “If you have a confirmed rattlesnake sighting, you can report it by calling: 1-888-WDNRINFO (1-888-936-7463).”