High Island American woodcock habitat crosswalk

What this adds

The official Forest Service species review gives us a useful historic link between High Island and American woodcock (Scolopax minor). It reports woodcock in old fields with shrub and young-tree cover, and in second-growth hardwood and conifer forests. The named associates include staghorn sumac, pin cherry, aspen, beaked hazelnut, red-osier dogwood, willow, apple, paper birch, sugar maple, red maple, and balsam fir.

This is an important complement to the existing High Island material. The 2015 MNFI survey describes boreal, dry-mesic northern, Nezewabegon, and shoreline communities, along with soils, tree structure, and disturbance history. The woodcock crosswalk adds a bird-centered early-succession and forest-edge interpretation that can be compared against the NLCD land-cover and canopy rasters, MNFI community records, and public observation records.

Historic demographic values

The Forest Service review reproduces High Island values of 85 percent hatching success and 89 percent nest success, attributed to Douglas A. Whitcomb’s 1974 study. These are preserved as historic secondary-source values only. They are not a current population estimate, and the original report’s sample sizes, definitions, and field tables still need to be checked.

The 2017 DNR management plan supplies an additional archival summary of the 1968–1971 field period. It describes the study as examining exploitation, immigration, singing-ground counts, wing collections, hunting effects, and behavioral limits on population growth. Its summary reports that extreme exploitation reduced the male population while immigration maintained the overall population, and that peenting counts were effective for measuring population trends. The 1993 MNFI report independently summarizes the study as a 78-page High Island investigation of population dynamics, hunting effects, singing-ground monitoring, and behavior, and reproduces the original report’s own abstract: the study’s population dynamics “suggested that the species could not sustain a high degree of hunting” on High Island.¹ This is the study’s stated conclusion as reported by a secondary source, not a figure independently checked against the original report’s data.

Source and catalog uncertainty

The official USGS catalogue identifies Whitcomb’s report as Michigan Wildlife Division Report No. 2720, OCLC 2060101, vi + 78 pages. The Forest Service bibliography gives No. 2702. This index uses the official catalog’s 2720 as the canonical identifier while preserving the secondary-source discrepancy. The USGS catalog page explicitly states that it has no digital-version link, and the original report scan remains a retrieval target.

How to use it in the map and KB

The evidence supports a candidate-habitat comparison, not a habitat-suitability claim. A useful next map can compare historic woodcock-associated cover with:

• old-field and shrub/young-tree patches in annual NLCD;
• canopy density and forest-edge structure in the NLCD canopy layer;
• High Island MNFI community polygons or site descriptions;
• soil moisture and organic-soil context; and
• GBIF and local bird observations, retaining their coordinate precision.

The result should show evidence classes separately: historic literature association, present-day mapped structure, and actual observations. Habitat class alone does not establish current occupancy.

High Island current-context comparison

The derived index now makes the comparison reproducible without turning it into a suitability model. The 2021 NLCD extract classifies 15.0921 km²: 8.4798 km² forest, 4.4055 km² wetlands, and 1.4634 km² barren rock/sand/clay. The 2025 extract reports 8.4771 km² forest, 4.4064 km² wetlands, and 1.8756 km² barren rock/sand/clay. The largest classified transition is 457 pixels from open water to barren land; that is a raster-class transition, not proof of shoreline change or habitat gain.

The SSURGO intersection covers 14.8993 km² and contains 13 map units. Its largest labels are Roscommon sand (3.9125 km²), Alpena–Kiva–East Lake soils (2.7296 km²), Belding–Breckenridge sandy loams (2.1087 km²), Deer Park–Dune land associations (4.0265 km² combined across undulating, rolling, and hilly units), and Lake beaches (1.0884 km²). These labels provide the soil and landform vocabulary needed for a future habitat analysis, but they are not field measurements at woodcock locations.

The 2017 MNFI index contains eight High Island occurrences across seven community types: boreal forest, dry-mesic northern forest, Great Lakes barrens, limestone cobble shore, mesic northern forest, open dunes, and sand and gravel beach. The GBIF snapshot retains three High Island American woodcock records, dated 1986 and 1988, all assigned to “High Island, Sect. 27” with an unknown coordinate-precision class. They are useful public-observation anchors, not standardized singing-ground counts or evidence of current occupancy.

The crosswalk therefore joins four distinct evidence layers: historic woodcock habitat associations; current broad land cover; county-scale soil map units; and public observation records. It does not draw candidate habitat polygons, assign any MNFI occurrence to a woodcock record, or claim that a soil, forest, wetland, or dune class predicts the species.

Limits

The original Whitcomb report is not yet held locally; the official catalog does not provide a digital copy. This record therefore does not reproduce its field methods, sampling frame, raw locations, or population estimate. The High Island habitat association is also not evidence that every listed cover type is present today or that woodcock occupy every such patch.

The generated JSON crosswalk preserves the extraction, source URLs, report number discrepancy, and retrieval boundary.

Added 3 August 2026. Recent changes