Here’s the introduction to their piece. We believe any growers using illegal, or for that matter, any pesticides that affect local flora and fauna should be prosecute with the full force of the law

The northern spotted owl has had many adversaries.

Three decades ago it was loggers, whose forays into the remote forests of the Pacific Northwest threatened the shy creatures, which have zero tolerance for the clatter of development.

Now, a new menace is taking root among the ancient trees: unpermitted marijuana farms suspected of spreading rat poison up the owl’s food chain, according to a study led by researchers at UC Davis in cooperation with the California Academy of Sciences.

“We have discovered a new potentially lethal threat to this struggling species that many conservationists have spent decades trying to save from extinction,” said Mourad Gabriel, lead author of the study and a researcher with the UC Davis Karen C. Drayer Wildlife Health Center.

Seven of 10 spotted owls and 34 of 84 barred owls collected between 2009 and 2013 tested positive for anticoagulant rodenticides, the study published Thursday in the journal Avian Conservation and Ecology shows.

The study area encompassed Humboldt, Mendocino and Del Norte counties, a region where increasing numbers of marijuana cultivation sites overlap with the owls’ hunting grounds, Gabriel said.

There are an estimated 15,000 marijuana farms in Humboldt County alone operating without regulatory oversight, Gabriel said.