Piping Plovers Nest on Three Apostle Islands as Lake Levels Shrink Their Beaches

Piping plovers explored Apostle Islands National Lakeshore early in the 2019 nesting season, looking for sites. Reports came first from Cat and Michigan Islands, but the birds ended up nesting on Long, Stockton and Outer Islands. Plovers began nesting on Long Island in the mid-1970s, and between 2006 and 2015 the greatest number of chicks hatched and fledged there, between 5 and 17 a year. High water and more storms in recent years have narrowed the beach habitat on Long Island, which probably prompted the early searching.

Island by island

Outer Island. The second year, to the park's knowledge, that plovers nested here. They chose the west side of the sandspit, south of the lagoon. Plovers nest on beaches away from trees and shrubs, which can hide predators, and among rocks that help hide the eggs.

Stockton Island. At the beginning of June, staff at Julian Bay heard the plover's distinctive "peep-lo" call and found a nest with 3 eggs. They closed a small area and placed a wire mesh exclosure over the nest to protect the eggs from predators and people. Adults go back into exclosures within minutes of setup and keep incubating.

A piping plover returning to her eggs inside an exclosure (NPS photo).

Long Island. Three pairs set up in the traditional nesting area. One nest was soon abandoned. A second held 4 eggs, which hatched, but the adult male and one chick disappeared. Normally females begin heading south within a week of hatching and males tend the young at the end, but this female stayed until the three remaining chicks fledged. The third nest had 3 eggs; on June 24 a monitor saw that the adults had left it.

A full clutch is 4 eggs. Plovers make a simple scrape in the sand and rely on the eggs' camouflage (NPS photo).

A rescue by captive rearing

Monitors are trained to spot the signs of a nest about to fail, and some nests are inevitably lost each season, most often when a predator takes an adult or high water washes the nest out. For the abandoned Long Island nest, a monitor consulted park staff and moved the eggs to a portable incubator for transport off the island. Staff met the boat, drove the incubator to the Upper Peninsula and handed it to Great Lakes Piping Plover staff, who took it to the Captive Rearing Station in Pellston, Michigan, where the eggs were checked by candling. The three chicks were raised and released with others of the same age at Whitefish Point on August 6.

The eggs after arriving at the Pellston Captive Rearing Station, where staff candled them to check that they were still viable (NPS photo/Peggy Burkman).

Banding

On July 15 staff banded chicks on all three islands: four on Long Island, three on Stockton and two on Outer. Each gets a single metal band and colored plastic bands on the upper and lower legs, which identify the bird and where it hatched. Bands make population counts more accurate and show whether and how birds move between Great Lakes nesting grounds, which in turn shows how genetically diverse the population is, important to its long-term survival.

The birds

Plovers in the park belong to the endangered Great Lakes population, rare because of habitat loss from commercial, residential and recreational development, natural predators, and nest disturbance by people. Their Latin name, Charadrius melodus, refers to the melody of the peep-lo call. Adults are about the size of robins, with buff backs and pale underparts, dark bands across the forehead and around the neck, and a dark-tipped short bill; the bands are more developed in males. A red leg band on a male marks one reared at the captive rearing station in Pellston.

Who manages them, and how to help

Management involves the Bad River Band of the Lake Superior Tribe of Chippewa Indians, the U.S. Fish and Wildlife Service, the Wisconsin Department of Natural Resources, The Nature Conservancy and the Johnson family, and University of Minnesota researchers, with funding in recent years from the Great Lakes Restoration Initiative. Visitors can help by:

• staying away from nesting enclosures, walking near the water where nests are marked and obeying closure signs;
• keeping dogs on a non-retractable 6-foot leash, since dogs can chase plovers and cause nests to be abandoned;
• leaving lake vegetation and driftwood on beaches, which give chicks food and shelter;
• learning more at GreatLakesPipingPlover.org.

Piping plover tracks (NPS photo).

Sources

• National Park Service, Apostle Islands National Lakeshore, Piping Plovers On The Move; rewritten in hubnx's own words.