Common Terns Return to Lake Butte des Morts

Date: September 01, 2008

By Art Techlow and Nicole DeKeuster.

In March of this year the Butte des Morts Conservation Club, together with the WDNR, built several nesting islands on Lake Butte des Morts. We are happy to report that we successfully attracted eleven nesting pairs of the State Endangered Common Tern.

The island is only about 30 x 40 feet across the top and 3 ½ feet above the lake surface. It is small, remote, unvegetated, and predator free – just what common terns like for nesting. Art Techlow, Biologist with the WDNR, counted eleven common tern nests with eggs on the island at the end of July. Adult terns had no problem warding off potential threats to their chicks, they defend their nests by swooping and diving at the perceived menace. Most often these are large birds such as geese, pelicans and cormorants which might accidentally trample nests and eggs. But sometimes they go after humans, as Art found out after being struck in the head several times over the years while checking nesting sites.

It only takes about three weeks for the young to fledge (i.e. to be able to fly), and by late August all the adults and their young had left the island. This is typical; the birds quickly disperse to better foraging areas as the young take wing. (Common terns feed on minnows and other small fish by diving on the wing.)

The successful hatch of common terns on the newly constructed island is the first on Lake Butte des Morts in well over ten years. And this new site is one of only four in Wisconsin currently being used by the birds for nesting. The success of these birds represents the strong commitment of all those involved in supporting, funding, designing and constructing this project.

Common terns are just one of many species that have been adversely affected by PCB contamination in the lower Fox River and Green Bay. The funds for construction of the islands came from the settlement reached with the companies responsible for releasing the toxin into our environment. No taxpayer money was used.

The island is part of the 1183 acre Terrell’s island property owned by the non-profit Butte des Morts Conservation Club. The property is open to the public and more information can be found on their website The club’s mission is to provide Conservation, Preservation, and Restoration (CPR) to the wetlands and wildlife habitat of Lake Butte des Morts, its' tributaries, and surrounding wetlands.