Site is important to one or more species listed as endangered or threatened in Wisconsin.
Site regularly supports significant breeding or non-breeding densities of one or more of the following species listed as endangered or threatened in Wisconsin. This applies to use of the site for breeding, wintering, or migration. The site should be of regular and recent (within the last 10 years) occurrence. Thresholds will vary but may be ≥ 1% of the state’s population within a season, if known, or one of the 10 sites with the highest regularly occurring numbers.
Endangered: Red-necked Grebe, Snowy Egret, Trumpeter Swan, Peregrine Falcon, Piping Plover, Caspian Tern, Forster’s Tern, Common Tern, Barn Owl, Loggerhead Shrike, Yellow-throated Warbler, Worm-eating Warbler
Threatened: Great Egret, Yellow-crowned Night-heron, Osprey, Red-shouldered Hawk, Greater Prairie-chicken, Spruce Grouse, Yellow Rail, Acadian Flycatcher, Bell’s Vireo, Kentucky Warbler, Hooded Warbler, Cerulean Warbler, Henslow’s Sparrow.
Site is important to one or more species identified as high conservation priorities in Wisconsin.
Site regularly supports significant breeding populations of one or more of the following species identified as high conservation priorities in Wisconsin. The site should be of regular and recent (within the last ten years) occurrence. Thresholds are stated below.
For the following species, the site should support 5 or more breeding pairs or be one of the 10 sites with the highest regularly occurring numbers:
Least Bittern, American Bittern, American Black Duck, Redhead, Hooded Merganser, Northern Harrier, Bald Eagle, Northern Goshawk, Sharp-tailed Grouse, Whooping Crane, Upland Sandpiper, Wilson’s Phalarope, Black Tern, Belted Kingfisher, Black-billed Cuckoo, Great Gray Owl, Short-eared Owl, Red-headed Woodpecker, Black-backed Woodpecker, Olive-sided Flycatcher, Black-throated Blue Warbler, Connecticut Warbler, Louisiana Waterthrush, Le Conte’s Sparrow, Nelson’s Sharp-tailed Sparrow.
For the following species, the site should support 25 or more breeding pairs:
Blue-winged Teal, Ring-necked Duck, Virginia Rail, Ruffed Grouse, American Woodcock, Common Nighthawk, Whip-poor-will, Yellow-billed Cuckoo, Chimney Swift, Yellow-bellied Sapsucker, N. Rough-winged Swallow, Eastern Wood-pewee, Willow Flycatcher, Yellow-bellied Flycatcher, Least Flycatcher, Yellow-throated Vireo, Sedge Wren, Marsh Wren, Brown Thrasher, Veery, Wood Thrush, Prothonotary Warbler, Blue-winged Warbler, Golden-winged Warbler, Nashville Warbler, Chestnut-sided Warbler, Blackburnian Warbler, Black-throated Green Warbler, Cape May Warbler, Ovenbird, Black-and-white Warbler, Mourning Warbler, Canada Warbler, Rose-breasted Grosbeak, Purple Finch, Field Sparrow, Swamp Sparrow, Grasshopper Sparrow, Dickcissel, Bobolink, Eastern Meadowlark, Western Meadowlark.
Site harbors an assemblage of species associated with a habitat type that is representative, rare, or threatened in Wisconsin.
Site regularly supports an assemblage of species wholly or largely associated with a habitat type that is representative, rare, or threatened in Wisconsin. This criterion mainly will cover relatively large areas that support, or could be managed to support, populations of species with particular habitat requirements. Sites will be judged based on the completeness of the avian assemblage. “Representative” sites are those of exceptional extent or undisturbed condition. Rare/threatened habitat types and examples of associated bird species are listed below; other species that occur may also be considered as part of the listing.
Hemlock Forest: Northern Goshawk, Red-shouldered Hawk, Solitary Vireo, Black-throated Green Warbler, Blackburnian Warbler, etc.
Pine Forest (dry, mesic, wet; white pine, red pine, Jack pine, some hardwoods): Northern Goshawk, Black-backed Woodpecker, Least Flycatcher, Solitary Vireo, Common Raven, Red-breasted Nuthatch, Brown Creeper, Veery, Hermit Thrush, Nashville Warbler, Black-throated Green Warbler, Blackburnian Warbler, Pine Warbler, Connecticut Warbler, Canada Warbler, Red Crossbill, Pine Siskin, Evening Grosbeak, etc.
Boreal Forest (spruce, fir, birch, aspen): Solitary Vireo, Swainson’s Thrush, Northern Parula, Magnolia Warbler, Cape May Warbler, Yellow-rumped Warbler, Purple Finch, Red Crossbill, Pine Siskin, Evening Grosbeak, etc.
Conifer Swamp (white cedar, tamarack, black spruce, black ash): Northern Saw-whet Owl, Black-backed Woodpecker, Olive-sided Flycatcher, Yellow-bellied Flycatcher, Philadelphia Vireo, Gray Jay, Boreal Chickadee, Golden-crowned Kinglet, Ruby-crowned Kinglet, Nashville Warbler, Cape May Warbler, Connecticut Warbler, Canada Warbler, Purple Finch, Pine Siskin, etc.
Upland Hardwood Forest (maple, basswood, oak): Red-shouldered Hawk, Broad-winged Hawk, Barred Owl, Whip-poor-will, Pileated Woodpecker, Eastern Wood-Pewee, Acadian Flycatcher, Yellow-throated Vireo, Blue-gray Gnatcatcher, Wood Thrush, Cerulean Warbler, Worm-eating Warbler, Louisiana Waterthrush, Kentucky Warbler, Hooded Warbler, Scarlet Tanager, etc.
Floodplain Forest (silver maple, river birch, green ash): Yellow-crowned Night-Heron, Red-shouldered Hawk, Barred Owl, Yellow-bellied Sapsucker, Pileated Woodpecker, Brown Creeper, Cerulean Warbler, American Redstart, Prothonotary Warbler, etc.
Oak Savanna: Red-headed Woodpecker, Eastern Kingbird, Blue-gray Gnatcatcher, Eastern Bluebird, Field Sparrow, Lark Sparrow, Orchard Oriole, etc.
Pine Barrens: Sharp-tailed Grouse, Upland Sandpiper, Common Nighthawk, Eastern Kingbird, Eastern Bluebird, Brown Thrasher, Chestnut-sided Warbler, Rufous-sided Towhee, Clay-colored Sparrow, Vesper Sparrow, Brewer’s Blackbird, etc.
Shrub wetlands (alder thicket, shrub carr): Green-backed Heron, Black-billed Cuckoo, Alder Flycatcher, Willow Flycatcher, Eastern Kingbird, Gray Catbird, Golden-winged Warbler, Yellow Warbler, Mourning Warbler, Common Yellowthroat, Rose-breasted Grosbeak, etc.
Grasslands (dry, mesic, or wet prairie; idle warm or cool season grasses/forbs; dry oldfield): Northern Harrier, Greater Prairie-Chicken, Upland Sandpiper, Barn Owl, Short-eared Owl, Field Sparrow, Henslow’s Sparrow, Grasshopper Sparrow, Dickcissel, Bobolink, Eastern Meadowlark, Western Meadowlark, Brewer’s Blackbird, etc.
Sedge meadow: American Bittern, Northern Harrier, Virginia Rail, Sora, Yellow Rail, Sandhill Crane, Sedge Wren, Le Conte’s Sparrow, Nelson’s Sharp-tailed Sparrow, Bobolink, etc.
Open bog/Muskeg/Poor fen: Northern Harrier, Yellow Rail, Short-eared Owl, Palm Warbler, Lincoln’s Sparrow, etc.
Emergent/Submergent/Floating-leaved marsh: American White Pelican, Least Bittern, American Bittern, Blue-winged Teal, Redhead, Ruddy Duck, King Rail, Virginia Rail, Sora, Common Moorhen, American Coot, Forster’s Tern, Black Tern, Marsh Wren, Yellow-headed Blackbird, etc.
Great Lakes shoreline/dune/beach: Piping Plover, Killdeer, Caspian Tern, Common Tern, etc.
Site where significant numbers of birds concentrate for breeding, migration/staging, or wintering.
Sites that regularly, but not necessarily yearly, hold significant numbers of one or more species, breeding or non-breeding, including migration. The numerical thresholds provided below are guidelines, not absolute numbers. Except where noted, numerical estimates should be based on total counts of birds made over a single, short period of time (e.g., one day), not on cumulative totals. Introduced, feral, and nuisance species (resident Canada Goose, European Starling, House Sparrow) should not be counted.
WI-4a. Single species: The site is known or thought to hold 5% or more of the state’s population of a species in a given season. If population thresholds are unknown, this may be applied to the one site with the largest proportion of a species’ population.
WI-4b. Waterfowl: e.g., ducks, swans, geese (excluding resident Canada Goose), etc.
- Breeding: The site regularly supports at least 500 pairs
- Wintering: The site regularly supports at least 500 individuals
- Migration/staging: The site regularly supports at least 5000 individuals
WI-4c. Shorebirds: e.g., plovers, sandpipers, snipe, woodcock, phalaropes, etc.
- Migration/staging: The site regularly supports daily totals of at least 200 individuals, or at least 10 species total for the season (for AMERICAN GOLDEN PLOVER: 25 individuals; for GREATER YELLOWLEGS: 25 individuals; for BUFF-BREASTED SANDPIPER: 10 individuals).
Colonial: e.g., pelicans, herons, egrets, terns, etc. (this criteron excludes cormorants and gulls).
- Breeding: The site regularly supports at least 50 pairs.
- Migration/staging: The site regularly supports at least 100 individuals.
Non-colonial: e.g., loons, grebes, rails, bitterns, etc.
- Breeding: The site regularly supports at least 25 pairs of any mix of species.
- Migration/staging: The site regularly supports at least 100 individuals or the site regularly supports at least 2000 cranes.
WI-4e. Landbirds and Raptors: Landbirds include flycatchers, vireos, warblers, sparrows, etc. Raptors include eagles, hawks, falcons, etc. The site is regularly an important migratory stopover or seasonal concentration site for an exceptional number or diversity of migratory landbirds and/or raptors. Thresholds have not been set except where noted (see below) due to the scarcity of quantitative data, but the site should clearly be an outstanding staging area, migratory stopover, wintering area, or breeding area.
Wintering raptors: for GOLDEN EAGLE: 5 individuals; for BALD EAGLE: 25 individuals; for SHORT-EARED OWL: 10 individuals.
Site is important for long-term research and/or monitoring projects that contribute substantially to ornithology, bird conservation and/or education.
These are generally sites with a distinguished record and/or unique potential for long-term research and monitoring or exceptional educational value. Such sites may occur in urban, suburban, rural, or other settings. Evidence should be cited showing the area’s value, such as publications of research conducted at the site.