Metal levels in feathers of cormorants, flamingos and gulls from the Coastof Namibia in Southern Africa

Arsenic, cadmium, chromium, lead, manganese, mercury, selemium, and tin con centrations were measured in the feathers of Cape cormorant (Phalacrocorax capensis), Hartlaub's gull (Larus hartlaubii), kelp gull (Larus dominicanus ), and lesser flamingo (Phoeniconaias minor) from the coast of Namibia in s outhern Africa. Metal concentrations in feathers represent the concentratio ns in the blood supply at the time of feather formation. Cape Cormorants ar e piscivores; kelp gulls are primarily piscivores; Hartlaub's gull is an om nivore; and lesser flamingos eat primarily blue-green algae and invertebrat es filtered from the water and sediment of hypersaline lagoons. We predicte d that metal concentrations would reflect these trophic level differences. There were significant species differences in the concentrations of all met als, with flamingos having the lowest levels, and cormorants having the hig hest levels of 4 metals but not mercury. The gulls had the highest levels o f mercury, perhaps reflecting their more scavenging behavior.