Resource Management

Common Tern Project and String Grid

The common tern project was initiated on Hennepin Island, Mille Lacs National Wildlife Refuge, in 1993. Common terns compete with ring-billed gulls for nesting habitat and this project allows terns to nest while discouraging gulls. During the nesting season, a string grid is installed over the southern portion of Hennepin Island. The grid acts as a barrier to ring-billed gulls, and is spaced to allow terns access to the island. This portion of the island is better suited for nesting common terns as they prefer to build their nests on ground with pea sized gravel and smaller rock.. The Mille Lacs Band of Ojibwe Department of Natural Resources is a partner on this project. Double-crested cormorants have a successful rookery on Spirit Island. The number of waterbird nests is surveyed annually.