Are illicit marijuana grows turning forest research into a dangerous science?

By Alastair Bland

In the forests of Northern California, illegal marijuana growers armed with guns are turning wildlife research into an unexpectedly dangerous profession.

As recently as five years ago, UC Davis biologist Mourad Gabriel said he could freely roam the woods tracking radio-collared bobcats and Pacific fishers, an endangered weasel-like predator, across the Coast Range and the Sierra Nevada. But the increasingly common presence of gun-toting weed growers is making that a dangerous proposition.

More than once, Gabriel or his colleagues have been chased or shot at, and at least one biologist has been captured and interrogated by pot growers, he said.

The marijuana industry is booming from what is called the “green rush,” and numerous plantations are appearing on public lands. In places, trees are cut down, and seasonal camps are built to accommodate growers, who often live on-site for the summer growing season and may guard their plantations with firearms.

As a result, Gabriel and his colleagues only conduct field work while accompanied by armed state and federal agents during the April-November growing season, and they avoid certain areas altogether where growers are suspected to be present. “Between 10 and 25 percent of our project area can’t be monitored at all during the growing season,” Gabriel said.

Marijuana growers don’t only threaten the safety of scientists. They use rodent poison in their grows and this has become a significant cause of death for nontarget species that sometimes eat culled rats and mice.

Gabriel has spent a decade observing fishers’ behavior and making regional population assessments. He said between 80 and 90 percent of fishers found dead in his study regions have contained rodent poison in their systems. He warns that the animals themselves and the ability of scientists to track them are being compromised by marijuana farmers.

“They have completely hindered our capacity to conduct science for the protection of an imperiled species,” he said.

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