Wild pigs roam on the loose in 56 of California’s 58 counties. … [E]specially in warm weather, pigs love to hang out in streams and ponds. “They’ll wallow in the water sources, which is one of the types of damage they do,” [Santa Clara Valley Open Space Authority Natural Resource Technician David] Mauk said. “[It] harms the sides of banks, causes a lot of erosion, damages the vegetation in those riparian areas and really destroys the habitat for other animals that want to use those, like the California red-legged frog.”

Other invasive species news:

• The Sopris Sun (Carbondale, Colo.): CPW working hard to keep zebra mussels from sticking