Wild pigs, feral pigs, feral hogs, or whatever you want to call them, are resident large animals found in many California counties.   These non-native critters became well established in the North Coast many decades ago, stemming from left-over open-range farm flocks from the 1800's through the 1940's, and from illegal but purposeful movement by clandestine efforts to increase sport hunting.   I have been told that many Sonoma County and Mendocino County feral pig populations really got a foot-hold during the depression era of the 1930's when banks foreclosed upon ranch properties, gathered up any profitable livestock for sale, but left the range-run hogs as they were not economically worth gathering at the time.

Wild pigs are usually viewed as, 1) a great sport hunting opportunity, or 2) a menace to rangelands and land managers... and these view points, of course, differ based upon perspective.  Here at the UC Hopland REC, wild pigs have become more common over the last 15 years, but their presence has low tolerance due to the potential risk of destructive damage to research plots.   

Control of wild pigs at HREC is carried out under the California Dept. of Fish & Game's ""Immediate Take" law, which is Fish & Game Code 4181.1.   This relatively unknown law allows the owner of livestock, land, or property, or that person's agent or employee, to immediately take any wild pig encountered upon that is damaging, destroying, or threatening to damage/destroy land or property.   No hunting license nor sport-hunting pig tag is required under these circumstances, but the DFG Regional Office must be notified within 24 hours.  Concise guidelines to this law can be found at:

http://www.dfg.ca.gov/wildlife/hunting/pig/depredation.html