Heptachlor seed treatment contaminates hawks, owls, and eagles of Columbia Basin, Oregon

Raptor Research
By: , and 


  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS | Dublin Core


We evaluated organochlorine residues in 12 species of hawks. owls, and eagles from the Columbia Basin of Oregon between 1978 and 1981. Companion studies showed that heptachlor epoxide (HE) induced adult mortality and reduced productivity of the Canada Goose (Branta canadensis) and American Kestrel (Falco sparverius).ln this study, brain tissue from raptors found dead and sample eggs from 90 nests were analyzed for organochlorines. The primary concern was HE that entered raptor food chains through the ingestion of heptachlor-treated seed by their prey. HE residues were detected in eggs from 9 of 10 species and ranged as high as 4.75 ppm (wet wt), but no definite effects of HE on productivity were readily apparent from the limited series of nests. However, the hazard of heptachlor seed treatments to birds of prey was demonstrated by the occurrence of lethal residues of HE in brain tissue of 3 Golden Eagles (Aquila chrysaetos) and 1 Rough-legged Hawk (Buteo lagopus). Other organochlorine pesticides were present in the eggs and significant relationships were found between DDE and eggshell thickness for the Swainson's Hawk (Buteo swainsoni) and Western Screech-Owl (Otus kennicotti), although shell thinning (9.6% and 7.4%) was below the generally accepted range where reproductive problems have been known to occur.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Heptachlor seed treatment contaminates hawks, owls, and eagles of Columbia Basin, Oregon
Series title Raptor Research
Volume 18
Issue 2
Year Published 1984
Language English
Contributing office(s) Patuxent Wildlife Research Center
Description 41-48
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Raptor Research
First page 41
Last page 48
Google Analytic Metrics Metrics page