Monarch migration stepping stones across the Great Lakes

Monarch habitat in the middle of Lake Michigan? Yes! One of America’s oldest national wildlife refuges is a Great Lakes migration route for migratory birds and other species, like monarchs. From urban to rural, and even remote geographies, we at the U.S. Fish and Wildlife Service protect habitat for native species. Take a few minutes to learn more about this remote beauty. 

On February 21, 1912, President William Howard Taft established Green Bay National Wildlife Refuge, our nation’s 28th refuge and only the second refuge in the Great Lakes region. Located in Lake Michigan, off the tip of Wisconsin’s Door Peninsula, the refuge started as a mere 2-acre island that was originally named Green Bay Reservation. Today, this essential stopover habitat for birds and other migratory species consists of five islands and is framed by Wisconsin and Michigan. 

Biologists and land managers have been roughing the waves and extreme weather of Lake Michigan to help colonial nesting waterbirds birds for more than 100 years, but the refuge boasts more than nesting birds. While they started with a small footprint that focused on bird conservation, botanists and other researchers from around the world have come to study the diverse plant life that has persisted here for millennia. In 2007, the refuge grew with the addition of Plum and Pilot islands, in Wisconsin. Later in 2015, Rocky Island and part of St. Martin Island, in Michigan, also grew this remote gem. 

Stepping stones across the Great Lakes 

The chain of islands running north off of Door County, Wisconsin, up to the southern part of Michigan’s Garden peninsula, act as a set of stepping stones for migratory birds and monarchs to rest and replenish their energy needs with ample supplies of food. The islands are also a geologically unique feature, being part of the Niagara Escarpment, a fault line extending from Niagara Falls through Canada, Michigan and Wisconsin. 

The islands that make up the refuge protect a special ecosystem type called alvar, a limestone covered by a thin soil layer, which is absent on the mainland. Some of the islands also contain northern mesic forest communities that are home to 45 species of concern. St. Martin Island supports 43 neo-tropical migrant birds and 26 species of greatest conservation need in Michigan. More than 400 plant species, including the federally threatened dwarf lake iris, have been found here, and the island’s broad shallow areas offshore, known as flats, are prime areas for spawning fish. 

Common sightings in the refuge include white-tailed deer, snakes and newts. You’re also likely to see water-loving birds like mergansers, ring-billed gulls, bald eagles, herons, egrets and pelicans, as well as birds that prefer woodland habitats, like warblers and pileated woodpeckers. If you’re lucky you might see an American redstart or a Caspian tern. 

Some of the species of plants found on the refuge have been completely decimated on the mainland, such as Canada yew, a shrubby understory species. Other species of concern found on the refuge include American sea rocket, dune goldenrod, white camas and climbing fumitory. 

You can visit! 

The Plum and Detroit Island units of Green Bay National Wildlife Refuge provide a beautiful backdrop for Door County, one of Wisconsin’s greatest tourism areas, and lures city dwellers from Milwaukee and Chicago throughout the summer season. The weather-sculpted landscapes and sense of isolation can leave visitors feeling that they are worlds away from their everyday lives. The feeling of seeing old lighthouses and other remnants of human history leave some with an eerie sense that they are not alone. 

This rich maritime geography has a dark and stormy past, being home to the most recorded shipwrecks in Lake Michigan. Squarely situated in Death's Door, also known as Porte des Morts, the refuge has the benefit of strong public support for keeping this history alive through the Friends of Plum and Pilot Island. Plum Island is home to one of the last remaining examples of U.S. Coast Guard Duluth-style crew quarters and Roosevelt-style boathouses in the Great Lakes. Friends of Plum and Pilot Island have been working with the U.S. Fish and Wildlife Service for more than a decade to preserve the many historical structures on the islands and are a valued partner. 

People typically visit Plum Island to learn about the cultural aspects of maritime life through an interpretive hike led by refuge staff and Friends docents. Annual events like the Door County Lighthouse Festival and the Ridges Sanctuary’s Festival of Nature provide excellent opportunities to visit and learn about the rich natural and cultural history of the islands. Wildlife observation and photography are always a part of the experience. You’re welcome to take the short half-mile hike across the island to see additional structures. Please note that while the trail is open to all, the structures remain closed to public access. The Plum and Detroit Island units are open Memorial Day weekend through Labor Day. If you make the trip out to experience it for yourself, plan ahead.

Learn more about Green Bay National Wildlife Refuge.