Trial monitoring of pesticides in wings of mallards and black ducks.

CONCLUSIONS: The results of the trial monitoring indicate that mallard and black duck wings are satisfactory monitoring media, that pesticidal residues were present in all pools, and that due to the variability in levels, the pool size should not be reduced from 25 wings unless there is a wing shortage. Differences in DDE residues between adult and immature wings of both species indicate that the age classification should be maintained in sampling. For analytical reasons, State identification will be necessary in nation-wide monitoring even though significant residue differences between New York and Pennsylvania wings were not demonstrated.