"Traces of the rat poison, Brodifacoum, have been found in two little blue penguins that died in the Hauraki Gulf, a month after the Department of Conservation dropped the poison on Rangitoto and Motutapu islands...Is makes us wonder if these people know what they're doing. We've all read the reports about bait coming down like hail on fishermen in the vicinity of the islands, it doesn't take much to guess that birds in the area, including penguins, may have ingested some of it.
Poison-drop project manager Richard Griffiths said the finding of Brodifacoum was "alarming" and DoC did not know how it had happened....
DoC's resource consent to drop Brodifacoum on Rangitoto and Motutapu envisaged that some of the poisoned cereal baits would end up in the sea, and fishermen reported seeing pellets fall into the ocean at the time...." (See our blog post: Mass poison drops scheduled to wipeoout pests)
"Brodifacoum is a highly lethal anti-coagulant poison used to control not only rodents but also possums. It's is highly lethal to mammals and birds and extremely lethal to fish. It is a highly cumulative poison.
The American Bird Conservancy cites several studies indicating that secondary poisonings of predatory birds and animals are common due to the extreme persistance of the pesticide within both target and non-target species. It may also be dispersed by insects that feed on poisoned bait without harm and retain the pesticide within their bodies." - Wikipedia