Powell and Cuthbert Piping Plover habitat and reproductive success on Great Lakes islands, 1987–1990

Why this source matters

This is the strongest direct bird–dune–vegetation connection currently held for the archipelago. Powell and Cuthbert searched Beaver and High Islands every breeding season from 1987 through 1990, walking beaches both along the shoreline and behind the dunes. Potential habitat was surveyed weekly; active nests were observed every two to five days from at least 25 meters, and nests were checked one to four times per week until hatching or failure.

The study found nesting Piping Plovers on Beaver and High Islands in all four years. It reported no plovers on South Fox, Garden, Hat, Hog, Pismire, Squaw, Trout, or Whiskey Islands during the study, and none on the Manitou Islands. Those are effort-bounded non-detections, not claims of historical or current absence.

Dune, substrate, and vegetation mosaic

The western shores of Beaver and High were described as large dune systems and wide sand beaches. The recurring sequence was a smaller foredune 20–40 meters from the lake, a flat area of cobble mixed with sand, and a larger inland dune system. The lake-facing beach generally had less than five percent vegetation, a one-to-three-meter wrack line, and ephemeral pools with sedges.

The foredune vegetation was primarily willow (Salix glaucopylloides), beach grass (Ammophila breviligulata), and bearberry (Arctostaphylos uva-ursi), with 75–100 percent cover. The intermediate dune area was patchily vegetated, with bearberry dominant and raised cobble strips running parallel to the foredunes. This makes the study directly useful for joining the bird evidence to the project’s soils, geology, dunes, wetland, land-cover, and natural- community layers.

Beaver Island sites

One pair nested at McFadden’s Point in both 1988 and 1989. The state-owned site was described as undeveloped and relatively undisturbed; the nests were on the inland side of the foredune, on raised cobble surrounded by sand and sparse vegetation. In 1990, two pairs nested at Donegal Bay, a developed summer-home area where plovers had not nested for more than fifteen years. One nest was within 100 meters of a cottage; another was 34 meters from a road and had cottages 100–300 meters away.

All four Beaver nests were behind the foredunes. Their mean distance was 69 ± 7 meters from the lake and 10 ± 4 meters from the dunes; mean beach width was 34 ± 1 meters and mean dune width 25 ± 4 meters. Predator exclosures and a 50–100-meter seasonal closure were used at Donegal Bay.

High Island sites

High Island’s western beach supported nesting in all four study years. Five of eight nests there were behind the foredunes in cobble and sparse vegetation; those sites averaged 87 ± 9 meters from the lake and 30 ± 8 meters from the dunes, with beaches 23 ± 3 meters wide and dunes 32 ± 5 meters wide. Three nests were on the lake side of the dune; one was destroyed when a storm washed 25 meters onto the beach.

The northeastern point also supported nests in 1988 and 1989 on raised cobble. Herring Gull nests were within 20 meters, and 7,000–10,000 Ring-billed Gulls nested approximately 150 meters west. The paper associates these nearby gull colonies with poor chick outcomes, while retaining the precise mechanism as an observation-based interpretation rather than a general predator model.

Reproductive outcomes and management

Across both islands, annual breeding-pair counts were 2, 4, 5, and 5 from 1987 through 1990. Hatching success was 100%, 92%, 80%, and 92%; fledging success was 63%, 50%, 13%, and 18%; and mean young fledged per nest ranged from 2.5 to 0.4. Storms, American Crow predation, gulls, a Great Horned Owl, and human disturbance were documented or implicated in failures. The paper reports that 1990 exclosures protected all Beaver eggs, but high hatching success did not translate into sufficient recruitment.

The central habitat finding is that plover habitat was not just the open beach. Five of eight High Island nests and all described Beaver nests were behind the foredunes. Chicks crossed dunes through dense vegetation to reach the lake and foraged near ephemeral pools and vegetative cover. Because surveys restricted to the lake-facing beach can miss inland foredune habitat, the article provides a direct methodological warning for future mapping and monitoring.

Map and evidence limits

The article includes a general map of northern Lake Michigan islands, but no nest-coordinate table or georeferenced occurrence layer. The structured index therefore retains named sites, distances, island comparison results, and habitat measurements without inferring points or polygons. It is a primary study of 1987–1990 conditions, not current monitoring or a complete species census.

Added 3 August 2026. Recent changes