Fierce yet adorable, Humboldt martens have been described as the west coast’s own Tasmanian devils. The biologist Tierra Curry compares the red-chested mammal to another small, tenacious creature: “It’s a kitten that thinks it’s a honey badger,” she said. “It will crawl right into a bee nest and eat the honeycomb and larvae, getting its face stung the whole time.”

But there are some dangers that the marten cannot withstand – such as marijuana cultivation.

The state of California has announced that it is seeking to declare the Humboldt marten an endangered species, owing to the risks it faces from deforestation and, surprisingly, the cannabis industry. It is not the only species for which pot poses a lethal problem.

Humboldt martens ‘symbolize the wild heart of the forest’, says a researcher. Photograph: Mark Linnell, US Forest Service

Martens live in dense forests where low branches, decaying logs and evergreen bushes provide them with cover from predators like coyotes and bobcats. Along with honey they eat lizards, insects, birds, voles, squirrels and flying squirrels. “They are secretive deep forest dwellers,” said Curry, a senior scientist with the Center for Biological Diversity, a not-for-profit advocacy group that has petitioned state and federal authorities to list the animal as endangered. “They symbolize the wild heart of the forest.”

But as redwood forests have shrunk in northern California, so has the marten population. There are two populations, with 100 in Oregon and an estimated 200 in three northern California counties – which, unfortunately for them, overlap with California’s Emerald Triangle, an epicenter of cannabis cultivation.

In one county alone, Humboldt, there are thought to be 4,000 to 15,000 cannabis cultivation sites on private property, in addition to illegal or “trespass grows” on public or tribal lands. Not only is forest habitat lost to cannabis crops, but many growers in Humboldt use anticoagulant rodenticides to keep rodents from chewing through irrigation lines or eating their food supplies.

This inserts the poison into the forest food webs, which can cause birds and mammals that prey upon rodents – such as the marten – to die from uncontrollable internal bleeding. The rat poison and pesticides also run off into rivers, where wild salmon are at less than 5% of their historical population.



‘They are secretive deep forest dwellers.’ Photograph: Mark Linnell, US Forest Service

In Humboldt county, 70% of northern spotted owls and 40% of barred owls found dead or killed tested positive for poison in a recent study. The deaths of a number of fishers, rare, weasel-like forest-dwelling mammals related to martens, have been directly attributed to rat poison used by cannabis farmers.

While specific data on martens is lacking, “it’s like they all shop at the same grocery store. And we have clear and stark evidence that the food web for the northern spotted owl is contaminated, and martens live in the same habitat,” said Mourad Gabriel, co-director of Integral Ecology Research Center and the lead author of the study.

Any protections approved by California would only apply within the borders of the state – it is far more difficult to obtain powerful federal protections – and would not apply to the large tracts of federally owned land in California.

In Oregon, there are other kinds of threats. It is legal there to trap the animals commercially, and there is no limit on how many. Their silky, mink-like pelts sell for about $20 each on the fur market.