In the years before the refuge's founding, multiple expeditions were made to the islands. Ornithologist Henry L. Ward, then-curator of the Milwaukee Public Museum, visited the area numerous times to study the herring gull populations. While visiting Gravel Island in 1906 and 1907, Ward noted very large colonies of herring gulls as well as Caspian terns while observing their behavior and collecting specimens from the island. In 1913, the refuge was formed by executive order from Gravel Island and Spider Island to protect the breeding grounds of birds living there. Upon its formation it became the 29th refuge in the United States and third in the Great Lakes region. In 1970 the refuge became part of the Wisconsin Islands Wilderness Area, one of the smallest in the country. Many studies have been performed at the refuge since the 1970s, and recent efforts have focused on tagging of the birds and studying their migration habits and breeding. In 2009 the refuge became part of a Comprehensive Conservation Planning program which will help manage the refuge more efficiently. The plan is intended to provide long-term continuity in refuge management, ensure that the refuge is consistent with the policies of the National Wildlife Refuge System, and improve budgets for the refuge.
Geography and geology
The refuge covers divided between two islands: Spider Island, spanning, and Gravel Island at a size of. The refuge is located off the east side of the Door Peninsula in Lake Michigan near Porte des Morts or "Death's Door", and is in a geographically rugged part of the Niagara Escarpment. The islands are composed primarily of limestone, with little to no vegetation growing on them. They were shaped by years of receding water, powerful pre-glacial rivers, and advancing glaciers. As a result, the islands are mainly flat and rise only a few yards above the lake.
Wildlife and ecology
Flora
Spider Island had a birch-cedar-tamarack forest until the late 1970s, but succumbed to the thousands of birds living on the island. The trees of Spider island have now fallen over or been washed away and no permanent vegetation is known on Gravel Island.
Fauna
The refuge is home for to a wide array of bird species that either use the islands as nesting grounds or as a place of shelter. The great black-backed gull is known to have a small breeding colony on Gravel Island, and historically on Spider Island. In 1994 the species was discovered on Spider Island, making it the westernmost breeding on record at the time. Large colonies of herring gulls and double-crested cormorants are found on both islands, while a colony of Caspian terns can be found on Gravel Island. Scattered populations of waterfowl nest on Spider Island; these include the Canada goose, American black duck and mallard.
