Rg. Harper et al., ORGANOCHLORINE PESTICIDE CONTAMINATION IN NEOTROPICAL MIGRANT PASSERINES, Archives of environmental contamination and toxicology, 31(3), 1996, pp. 386-390
Organochlorine pesticide levels were determined in Neotropical migrant
passerines which have populations reported to be declining. Pesticide
residues ranging from 0.385 to 27.4 ng/g were found in 19 of 21 birds
, including both Hatch Year (HY) and After Hatch Year (AHY) age classe
s of nine different species. Eighteen of the 19 birds contained p,p'-D
DE, while dieldrin was found in 16 birds and heptachlor epoxide was pr
esent in 10 birds. There were no significant differences in pesticide
levels between HY and AHY birds, suggesting that HY birds are exposed
to pesticides in their diet on the breeding ground or that pesticides
are acquired from contaminated mothers, or both. Pesticide levels were
not related to gender. Although the effects of these low residue leve
ls on passerine fecundity are unknown, their presence has potential co
nservation implications for passerines and for the raptorial birds tha
t feed upon them.