Outer-island and legacy ecology evidence index

What this index does

The outer-island record is not one homogeneous survey. It is a connected set of evidence layers with different dates, methods, and geographic footprints. The generated index retains 68 source records from eight existing indexes and groups them by the island name reported by each source. The nested source record remains available for exact wording, pages, occurrence identifiers, species lists, and evidence limits.

This makes the ecology corpus broader without flattening its uncertainties. The 2015 MNFI addendum, the 2019 Fox prioritization, the EGLE mapped-dune reports, the Whiskey cormorant study, and the 1999/2002 MNFI records can now be searched together while remaining visibly different kinds of evidence.

North Fox and South Fox

North Fox has two complementary layers. The 2019 MNFI prioritization preserves three historical natural-community occurrences—boreal forest, mesic northern forest, and northern hardwood swamp—with old survey dates, plus candidate open-dune and sand-and-gravel-beach targets. The later EGLE material records 2021 MNFI survey descriptions in mapped dune complexes 76 and 77. MDC 76 is a 105.4-acre southwestern parabolic barrier-dune complex with a maximum mapped height of 153.2 feet and four documented natural-community occurrences: open dunes, boreal forest, mesic northern forest, and sand-and-gravel beach. The report counts two rare-plant and two rare-animal element occurrences there.

The occurrence descriptions connect active foredune, blowouts, burial and abrasion to stabilized mesic forest, boreal forest, and shoreline habitat. The tree record includes northern white-cedar, paper birch, balsam fir, aspen, sugar maple, green ash, red oak, basswood, beech, maple, ironwood, and Canada yew. A sugar maple was estimated at 236 years and a mature cedar at more than 300 years in the mesic forest; several boreal-forest cedars were estimated at more than 200 years. These are surveyed-stand age observations, not an islandwide age distribution.

South Fox is the strongest outer-island landscape connection currently held. EGLE mapped-dune complex 75 encompasses the island-scale dune-related topography: high west-facing and lower east-facing parabolic dunes, beach ridges, perched dunes, bluffs, and interdunal depressions. The overview is approximately 3,430 acres with 11.6 miles of shore and a maximum mapped height of 365.9 feet. It preserves eight 2021-surveyed natural-community occurrences: three open dunes, an interdunal wetland, boreal forest, mesic northern forest, sand-and-gravel beach, and clay bluff. The report counts eight rare-plant and seven rare-animal element occurrences.

South Fox’s forest and wetland records show why the Fox Islands belong in the same ecological conversation as Beaver, Garden, High, and Hog. Boreal forest on steep bluffs and dunes is dominated by uneven-aged northern white-cedar, with old trees, blowout edges, windthrow, erosion, and coarse woody debris. Mesic northern forest includes mature and old-growth sugar maple, beech, cedar, paper birch, basswood, red oak, and white ash. The interdunal wetland record documents standing water, calcareous indicators, rushes, sedges, beak-rush, native reed, toads, dragonflies, and feeding habitat for migrating shorebirds, waterfowl, and songbirds. These are occurrence-level descriptions, not a complete flora, fauna, or wetland-boundary inventory.

Garden, High, and Hog

The 2015 Garden/High MNFI addendum supplies detail that the newer broad raster layers cannot: shallow alkaline loams and loamy organics over limestone cobble in Garden’s boreal forest; alkaline sands and gravelly sands over acidic organic layers in High’s boreal forest; acidic sands in High’s dry-mesic forest; and old sugar-maple, yellow-birch, hemlock, oak, and cedar structure in High’s Nezewabegon Forest. It also adds 2015 bat-acoustic detections, rare invertebrates, mollusks, incidental fauna, and community-priority information. The source is a targeted addendum, not a complete inventory.

Hog connects the older MNFI wetland record to the newer mapped-dune layer. The 1999 Baldimore Bay observation names Great Lakes marsh, northern fen, interdunal wetlands, and swamp forest, with northern white-cedar and emergent marsh vegetation under unusually low water. EGLE MDC 101 covers a smaller northwest wooded dune-and-swale and shoreline setting, with Great Lakes marsh, limestone cobble shore, and mesic northern forest. The mesic-forest description includes red oak, white pine, red maple, white ash, basswood, cedar, paper birch, and mature-to-old-growth trees estimated at roughly 146–203 years. Only part of the larger occurrences lies inside the mapped complex.

Whiskey Island and birds

Whiskey’s evidence is structurally different. The 2017 MDNR management plan provides a broad cover-type baseline—mixed conifer, balsam fir, and aspen—plus a dated natural-heritage survey gap, colonial-waterbird habitat, and bald-eagle nesting context. The separate 2010 peer-reviewed cormorant study gives direct single-season evidence: early and late counts recorded 332 and 107 nests, respectively, with both ground and tree nests, and the study modeled chick survival and prey consumption. Those modeled values should not be converted into a current colony trend or islandwide bird inventory.

The 1999 MNFI report provides a different kind of bird evidence: standardized survey-period comparisons among Beaver, Garden, and Bois Blanc, targeted species work, and habitat-linked observations. The 2002 synthesis explains how natural-feature occurrences were digitized and used to define significant biodiversity areas. Together, these older records document the historical methodological bridge between field observations and map-based conservation planning; they do not replace current surveys.

Small-island historical ecology layer

The modern outer-island sources do not cover every small island in the same way. The visually verified GLO crosswalk supplies a separate historical layer for several of them:

These records are line- and page-bounded observations, not small-island inventories. The 1942 typed pages are deliberately not merged into the 1845–1849 handwritten layer: they have a different survey form, date, and observation vocabulary. Neither layer supplies a current wetland delineation, bird census, species-abundance estimate, or inferred habitat polygon. Their value is comparative: they keep small islands visible in the archipelago’s soil–shore–vegetation–wildlife history even where modern survey coverage is thin.

Coverage and map limits

The index’s coverage matrix is deliberately explicit:

• Beaver, Garden, High, and Hog have the richest combination of modern MNFI occurrence evidence and older targeted records, with Garden and High also receiving the 2015 detailed addendum.
• North Fox and South Fox now have the 2019 historical-prioritization layer plus 2021-surveyed EGLE mapped-dune descriptions; South Fox’s mapped complex is island-scale, while North Fox’s two complexes are not a complete island inventory.
• Whiskey has direct bird-study evidence and management context but still has a dated natural-heritage survey gap.
• Bois Blanc and other islands appear as legacy comparison records in the 1999/2002 sources and should not be silently treated as part of the seven named Beaver-archipelago islands.

Representative occurrence points in the EGLE source indexes are retained as representative points, not natural-community boundaries. Candidate polygons from the 2019 prioritization are not confirmed occurrences. Island-level SSURGO, geology, NLCD, canopy, and GBIF summaries are contextual joins only. Missing records, zero public observations, missing coordinates, and source survey gaps are coverage results—not evidence that a species, forest type, wetland, or animal is absent.

The next high-value expansion is to seek authorized MNFI/MiFI occurrence geometry and source-safe survey tables for the Fox and Whiskey islands, then reconcile occurrence IDs and survey dates without replacing the source-bounded records preserved here.

Added 3 August 2026 · revised 9 August 2026. Recent changes