Gov’t-Funded Study Claims Illegal Pot Farms Are Poisoning Spotted Owls

Daily Caller News Foundation logo
Michael Bastasch Contributor
Font Size:

Illegal marijuana farms could be exposing endangered spotted owls to high levels of rat poison, according to a study funded by the U.S. Fish and Wildlife Service.

With the new year came the legalization of recreational marijuana use in California, which is expected to expand pot farms — legal and illegal — across the state. Researchers worry more and bigger illegal growing operations could harm spotted owls.

“Spotted owls are inclined to feed along forest edges,” Mourad Gabriel, a University of California-Davis and director of the group Integral Ecology Research Center, said in a statement.

“Because grow sites break apart these forest landscapes, they are likely source points for exposure,” said Gabriel, whose study will be published in the journal Avian Conservation and Ecology on Thursday.

There are thousands of unpermitted marijuana farms in Northern California, study authors estimate, meaning these grow sites can operate with no regulatory oversight. In places, like Humboldt County, pot growing operations are located in forests where spotted owls live.

Gabriel’s study found high levels of rat poison in spotted and barred owls. Seven of the 10 spotted owls and 40 percent of the 84 barred owls studied tested positive for rat poison.  The results support arguments that pot growing operations are exposing more animals to rat poison, Gabriel said.

Rat poison can keep owls and other animals from recycling Vitamin K, that can lead to clotting and internal bleeding. Gabriel and his co-authors studied dead spotted owls they found in the forest and samples taken from barred owls provided by other researchers.

U.S. officials listed spotted owls under the Endangered Species Act (ESA) in 1990, largely under arguments the timber industry was destroying the bird’s habitat. The ESA listing was a crippling blow to timber industry communities in Oregon, California and Washington.

But even as the timber industry was pushed out, spotted owl numbers did not recover. As it turned out, the barred owl has been driving spotted owls out of their habitat.

The U.S. Fish and Wildlife Service says “[s]potted owls are currently declining at an average rate of 2.9 percent rangewide each year.” Federal officials recently authorized the killing of 450 barred owls to relieve pressure on spotted owls.

Now, pot farms may pose another stressor for spotted owls, according to Gabriel’s study.

“When you have thousands of unpermitted grows and only a handful of biologists that regulate that for multiple counties, we’re deeply concerned that there aren’t sufficient conservation protective measures in place,” Gabriel said.

“If no one is investigating the level at which private marijuana cultivators are placing chemicals out there, the fragmented forest landscapes created by these sites can serve as source points of exposure for owls and other wildlife,” he said.


Follow Michael on Facebook and Twitter

Freedom of Speech Isn’t Free
The Daily Caller News Foundation is working hard to balance out the biased American media. For as little as $3, you can help us. Make a one-time donation to support the quality, independent journalism of TheDCNF. We’re not dependent on commercial or political support and we do not accept any government funding.

Content created by The Daily Caller News Foundation is available without charge to any eligible news publisher that can provide a large audience. For licensing opportunities of our original content, please contact