Historically, Thacher Island provided important nesting grounds for several species of terns. In 1956, 1,125 pairs of arctic, common, and roseate terns were recorded. However, since that time the terns have been displaced by opportunistic herring and black-backed gulls.
The island has the potential to be reestablished as a prime tern nesting area. The habitat remains ideal for tern breeding. Nesting terns are currently supported on islands strategically located to the north and south of Thacher Island, and could be attracted to re-establish nesting colonies on the refuge.
U.S. Fish and Wildlife Service biologists have developed a tern restoration proposal which describes the area and the preferred procedures to be incorporated into the restoration project. The proposed method allows for gulls to breed and nest in adjacent areas on the island but not within the specified restoration area.
Thacher Island is home to Cape Ann Light Station, recently designated a National Historic Landmark. A unique feature of this site are the twin light towers. The North Tower is located on refuge property. The South Tower and associated buildings are located on adjacent town property. The U.S. Fish and Wildlife Service works in partnership with the Thacher Island Association and the Thacher Island Town Committee to manage this important cultural resource.
Specific Management Goals for Thacher Island National Wildlife Refuge Include: