A UC Davis study shows more fishers are dying from rodenticides used on illegal marijuana farms. The mid-sized weasels are threatened under the California Endangered Species Act.
The study published in the journal PLOS ONE, shows increasing numbers of fishers are being exposed to and dying from greater varieties of rodenticides found on illegal pot farms. The study builds on 2012 research that recorded four fisher deaths and found a 79 percent exposure rate.
Since then nine more fishers have died, and exposure rates have increased to 85 percent. Mourad Gabriel with the Integral Ecology Research Center was the lead author.
"If the fisher is being impacted, and it’s an omnivorous carnivore that consumes a wide breadth of prey species, then other species of concern are most likely also at risk,” says Gabriel.
Gabriel says the number of illegal pot farms on public lands has also increased, which could account for the greater number of fisher deaths.