Bone, feathers, and liver were analyzed for lead in herring gull chicks (Larus argentatus) of two different ages. The highest levels were found in the bone, evidence of chronic exposure. No differences were found within the bones. Differences occurred between different bones, with the ribs having twice the amount of lead than any other bone. These studies indicate that type of bone affects lead levels; thus researchers should clearly state which parts of which bones are examined. It is also suggested that for humans consistent location should be used for analysis by in vivo X-ray fluorescence.