Cannabis use has been legalised in many US states, but it can still be grown illegally Daniel Brothers/Getty Images
Cannabis crops grown illegally on public lands along the west coast of the US are infringing on the habitats of native species, putting predators at risk of poisoning by dangerous pesticides.
Greta Wengert at the Integral Ecology Research Center in Blue Lake, California, first got an inkling of the scale of this human-wildlife conflict when cat-sized, ferret-like mammals called fishers (Pekania pennanti) turned up fatally poisoned by rodenticides. This was a surprise, considering the …
