Common Tern Monitoring

Save The River’s Common Tern Monitoring Program is a cornerstone of our long-term effort to restore and protect one of the St. Lawrence River’s most threatened species. Common Terns rely heavily on artificial nesting sites—such as navigation cells, shoals, and protected grids—because natural habitat has dwindled due to rising water, storms, disturbance, and competition from other birds.

Each year, Save The River staff and volunteers maintain, monitor, and improve several nesting sites across the Thousand Islands. Fall maintenance includes replacing protective fencing, clearing debris, and preparing the gravel substrate so terns can safely return and nest in spring. Seasonal work also involves taking down or rebuilding tern grids—structures that shield nests from predators during the vulnerable breeding months.

Community involvement is a vital part of this program. Volunteers help with hands-on work like grid removal, habitat preparation, and even building tern shelters and birdhouses. Recent family workshops at the Antique Boat Museum introduced young volunteers to woodworking as they built new shelters for upcoming nesting seasons—many using tools for the first time.

Throughout the breeding season, staff monitor nest activity, track population health, and document emerging threats. These efforts directly support the long-term recovery of the species and help guide conservation strategies for the River.

By maintaining safe nesting habitat and engaging the community in stewardship, Save The River is helping ensure that Common Terns continue to raise their chicks on the St. Lawrence for generations to come.