Significant Wildlife Habitats

Significant Wildlife Habitats are defined under Maine’s Natural Resources Protection Act (NRPA), which is administered by the Maine Department of Environmental Protection (DEP).

These habitats include:

Deer Wintering Areas (DWA) – forested areas used by deer when snow gets more than 12 inches deep in the open and in hardwood stands, when the depth that deer sink into the snow exceeds 8 inches in the open and in hardwood stands, and when mean daily temperature is below 32 degrees.

Inland Waterfowl / Wading bird Habitat (IWWH) – wetland complexes and a 250-foot-wide upland zone surrounding them. The quality of a wetland complex is determined by the dominant wetland type, the diversity of wetland types in the complex, the size of the wetland(s), the interspersion of the different types, and the relative amount of open water. IWWHs in organized townships were re-mapped and re-rated in 2008 using the most current, high resolution imagery.

Seabird Nesting Islands (SNI) – worldwide, seabirds live most of their lives over the open ocean and commonly nest on islands. Maine’s assemblage of seabirds utilize a wide range of habitat for nesting. For instance, some seabirds will nest on small, unforested islands vegetated sparsely with various grasses, forbs, and shrubs. Other seabirds require soil conditions suitable for burrowing. Some seabirds nest in rock crevices or on cliff ledges. In order to be suitable for nesting birds, these nesting islands must be disturbance-free, particularly from mammalian predators such as foxes, coyotes, and raccoons. Many seabird species were extirpated in Maine by the end of the 19th century but have recovered dramatically because of state and federal conservation laws and restoration efforts. In 1998, 234 Maine islands were afforded protection as Significant Wildlife Habitat for nesting seabirds under the Natural Resources Protection Act.

Shorebird areas – feeding and staging areas provide migrating shorebirds with the food resources they need to acquire the large fat reserves necessary to fuel their transoceanic migration to wintering areas. Shorebird areas can be feeding areas, roosting sites, or both. MDIFW surveys shorebird areas every year; this data is used to add, delete, or modify the mapped habitats.

Significant vernal pools (SVP) – also referred to as a seasonal forest pools, are natural, temporary to semi-permanent bodies of water occurring in shallow depressions that typically fill during the spring or fall and may dry during the summer. Vernal pools have no permanent inlet or outlet and no viable populations of predatory fish. A vernal pool may provide the primary breeding habitat for wood frogs (Rana sylvatica), spotted salamanders (Ambystoma maculatum), blue-spotted salamanders (A. laterale), and fairy shrimp (Eubranchipus sp.), as well as valuable habitat for other plants and wildlife, including several rare, threatened, and endangered species. For more information about identifying vernal pools and their regulation under NRPA, visit DEPs web site (see also SVP Field Form (PDF), Survey Timing Map (PDF), SVP Fact Sheet, and the 2011 Vernal Pool Press Release) (PDF)

Tidal Waterfowl / Wading bird Habitat (TWWH) – includes the following habitat types:

  • Eelgrass (Zostera marina) beds currently mapped by Maine Department of Marine Resources that are at least 2.5 acres in size
  • Mussel bars/beds
  • Emergent wetlands at least 2.5 acres in size
  • Mudflats at least 12.5 acres in size or adjacent to one of the above habitats such that the resulting complex is at least 2.5 acres in size

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