Heavy Metal and Selenium Levels in Feathers of Franklin's Gulls in Interior North America

Abstract

Although there are abundant data on heavy metals from coastal and oceanic seabirds, there is little for interior-nesting species. Heavy-metal and selenium levels in breast feathers of adult and fledgling Franklin's Gulls (Larus pipixcan) were examined in northwestern Minnesota, eastern South Dakota, eastern North Dakota, and central Montana in 1994. Metal levels in the feathers of Franklin's Gulls were within the range reported for other species. However, cadmium levels were at the high end and selenium levels at the low end. There were locational differences in metal levels for all metals for both adults and young. Using the levels in feathers of young as indicative of local exposure: (1) Lake Alice and Sand Lake had the lowest levels of lead and chromium, and the highest levels of mercury; (2) Agassiz and Benton had the lowest levels of manganese; and (3) Benton had the highest levels of selenium, lead, and chromium. There were age-related differences in metal levels for 19 of 24 possible comparisons. Adults had significantly higher levels of metals, except for selenium. Young birds had significantly higher levels of selenium than did adults.