Common Loon

Species Name: Gavia immer


Species Distribution in Massachusetts


Federal Rank: None

Massachusetts State Rank: Special Concern

Habitat Description

More water- dependent than any other inland bird, only coming to the shoreline in spring to breed and nest. It nests on islands or tall aquatic plants in large, clear northern lakes and ponds, and often returns to the same nesting site for years.

Threats to Survival

Lead poisoning induced by the ingestion of fishing sinkers lost by anglers is the foremost cause of adult loon mortality on New England lakes. Acid rain caused by pollutants from power plants and automobiles contaminates lakes with mercury, aluminum and cadmium which reduce loons’ reproductive success and render them more susceptible to infectious disease. Additional threats include pesticides, shoreline development, growing numbers of recreational boaters and flooding of nests due to human control of water levels in nesting areas.

Actions Recommended to Ensure Survival

Limit human development that destroys nests, limiting the use of lead sinkers by fishermen so that lead poisoning decreases, stricter environmental legislation to prevent acid rain and pesticide use, and limiting disruptive recreational boating.